GOOD GARDENING PRACTICES IN BARCELONA: CONSERVING AND IMPROVING BIODIVERSITY INDEX INTRODUCTION 3 LINED TREES 5 SHRUB GROUPS AND HEDGES 43 GRASSES, FIELDS AND GRASSLANDS 83 URBAN ALLOTMENTS 135 AQUATIC ENVIRONMENTS AND PONDS 173 CLIFFS, WALLS AND PARTY WALLS 221 C OURTYARDS, SMALL GARDENS, BALCONIES, TERRACES AND GREEN ROOFS 255 BIBLIOGRAPHY 299 ILNINTERDO DTURCETEISON A garden, a habitat Gardening in the city, public and private alike, brings remarkable benefits. Public green spaces offer a wide range of services: social, environmental, regulatory, cultural etc. Green spaces are privileged areas for health, enjoyment, meetings and relaxation. Private green spaces also offer the city environmental and eco- logical services, through gardening, a special interaction with nature. All together, the city’s green areas therefore constitute an asset that encourages quality ur- ban living. Barcelona has been promoting an expansion of green spaces and ways of managing them that favour ecosystem services and biodiversity conservation. It is within this context that this manual has been prepared, entitled Good gar- dening practices in Barcelona: conserving and improving biodiversity. The manual is a technical tool for disseminating good practices that will help to maintain quality green spaces, through work, above all, on their structures; the aim here is to improve their habitat conditions and thereby enable collaboration in the de- velopment of the flora and animal groups, vertebrates and invertebrates alike. It therefore encourages not just the conservation and improvement of the natural heritage, but also a richer contact between city residents and urban nature. The proposals it contains can be applied to both public and private areas. Its contents are organised into seven main chapters: lined trees; shrub groups and hedges; grasses, fields and grasslands; urban allotments; aquatic environ- ments and ponds; cliffs, walls and party walls; courtyards, small gardens, bal- conies, terraces and green roofs. Each of the chapters features conservation and biodiversity-improvement initiatives. The conservation strategy is basic and aimed at preventing the loss of our rich range of flora and fauna. For example, not using chemically synthesised phytosanitary products in urban allotments is a conservation initiative; by contrast, creating margins with shrubs and herbs to enrich habitats is an improvement initiative. The city offers shelter to a valuable range of flora and many species of protected fauna that require sensitive man- agement and which have a useful ecological function, such as controlling urban insect populations, of direct use not just for city residents but also for keeping certain pests in check. The manual takes an in-depth look at the relationships that arise in every natural ecosystem between the soil, vegetation and fauna, as well as the measures we can take to boost natural processes and relationships between their elements. We are talking about promoting a strategy for naturalising the city and making it a more balanced ecosystem, something that will necessarily benefit biodiversity conservation and the well-being and health of everyone. 3 INDEX INTRODUCTION 6 CONSERVATION INITIATIVES Using biological phytosanitary treatments 8 Selecting the period of application for phytosanitary treatments 10 IMPROVEMENT INITIATIVES Diversifying species of street trees 12 Selecting species of trees 14 Pruning needs to be made compatible with the presence of fauna 18 Managing woodland 20 Leaving some dry trees upright 22 Managing dead wood 24 Maintaining tree hollows 26 Planting plant species in tree pits 28 ANNEXE 1 Biological control in Barcelona 30 ANNEXE 2 Biodiversity associated with trees: birds and mammals 32 5 LINED TREES LININTERDO DTURCETEISON One of the most outstanding components of the urban environment are lined trees. Trees are found in parks, squares, gardens and, most especially, streets and avenues, making up rows that can reach several kilometres in length. Bar- celona is one of the European cities where trees are most evident, with some 160,000 specimens of lined trees that help to make up for the lack of large-sized green spaces in some districts, such as Eixample. On the other hand, some of the city’s parks —such as Montjuïc, Laberint d’Horta and Parc del Guinardó— boast large woodland areas. Lined trees provide environmental benefits to the entire urban system: they re- duce the effects of atmospheric pollution; regulate temperatures by tempering warming caused by the “urban heat island” phenomenon and prevent loss of heat during the winter; they capture CO2, which is the gas that contributes most to the greenhouse effect, and increase biodiversity. With regard to this latter aspect, trees lining streets act as connectors between green spaces, as they enable fau- na to move from one to the next, and each specimen constitutes a focus of at- traction in itself for various animals, invertebrates and birds in particular. As far as biodiversity is concerned, you can currently find over 150 species in Barcelona’s streets. Plane trees are by far the most abundant species. Note that many plane trees which can still be seen in public spaces date back to the sec- ond half of the 19th century. The last few years have seen other species making Managing lined-trees inroads into this dominance by plane trees, despite these remaining the identi- fying trees on the city’s major avenues. This is because their dominance in the Managing lined trees has to take account of issues such as pruning and use of city poses a high risk for lined trees in the event of widespread disease and also phytosanitary products. The tendency is for moderation in both cases, avoiding presents adaptation problems in an urban context (droughts, pollution, etc.) excessive pruning and overuse of certain products to control pests and diseases. This is generally a complex form of management, as it involves a type of work that Diversification strategy has a major impact on public spaces and also has consequences that are highly visible within the urban landscape. Interventions on the city’s trees need to find a balance between function and environmental improvement, if we are to obtain Diversifying Barcelona’s lined trees, along with an identifying criterion, has be- healthy trees, properly introduced in each context, which bring environmental come a long-term strategy that has been applied since 1995, to protect and im- services and are maintained as a cornerstone to biodiversity. prove this natural heritage. The aim is for lined trees to adapt well to Mediterra- nean-climate conditions — and in this sense to ensure they have no great water or fertilisation needs — ensuring they are capable of resisting the very pressure of the urban environment and can adapt to the specific features of the spaces they are allocated to, to provide maximum environmental services. And, in addi- tion to these considerations, the criterion of giving preference to native species or even to species that correctly adapted to our climate long ago. We also need to take account of other aspects that promote biodiversity when it comes to selecting species, such as fruiting, which encourages the presence of fauna. Not to mention that the large old trees form hollows that are usually occupied by birds. 6 7 CONSERVATION INITIATIVES Using biological phytosanitary treatments to cosus) and is becoming a key biological control of this plague in citrus cultiva- tion. Also common is the use of a predatory true bug (Anthocoris nemoralis) for conserve biodiversity controlling sycamore lace bugs (Corythuca ciliata), although it is worth pointing out that the results obtained in cities have not been fully satisfactory. That same true bug, however, has shown very effective results in controlling jumping plant lice (Cacopsylla pulchella), a pest that affects Judas trees (Cercis siliquastrum) and which excretes sticky secretions, lerps, which soil cars, urban furniture and pavements. These are all examples of biological control. (See annexe 1: Biological control in Barcelona). > Biological insecticides are used: for tackling pests and diseases through the direct use of living creatures or natural products (chemically synthetic products are excluded). Note, however, that certain biological insecticides, such as Bacil- lus thuringiensis bacteria, which are frequently used for tackling pine proces- sionaries (Thaumetopoea pityocampa), are not selective and can therefore ad- versely affect the pest’s natural predators. > Pheromones, inhibitors and repellents are used for tackling pests and dis- eases. It is true, however, that some incidents in Barcelona become emergencies and therefore require a rapid response. This means that a comprehensive manage- ment model combining chemical methods and biological control is becoming the most appropriate strategy in the urban context we are facing. Likewise, however, preference has to be given to biological-control methods and pesticides should Seven-spot ladybird (Coccinella septempunctata) be used as a last resort. Description/application Royal Decree 1311/12, establishing the framework of action for a sustainable use > A commitment to biological control. This of phytosanitary products, and the Register of Phytosanitary Products author- strategy involves fighting against align- ised by Spain’s Ministry of Agriculture, Food and Environment, are the reference ment-tree pests and diseases through their documents that have to be followed. natural enemies, whether predators, parasi- toid or pathogens. It means using organisms (useful fauna) that act against pests and help to reduce their population levels. To give a few examples of biological controls through direct predation, we could mention the control car- ried out by seven-spot ladybirds (Coccinella septempunctata) on aphids (fam. Aphididae) or vedalia beetles (Rodolia cardinalis), an- other type of ladybird, on the cottony cush- ion scales (Icerya purchasi). The larval stage of hoverflies (flies that resemble wasps) are also aphid predators. A species from the cales genus (Cales noacki), a small wasp, acts as a parasitoid against whitefly (Aleurothrixus floc- Aphidius colemani. Photo: Xelo Ribes 8 9 CONSERVATION INITIATIVES Selecting the period for applying phytosanitary So, before any treatment is applied, the time of year has to be taken into account and, in any case, where there is an urgent need for action, an exhaustive inspec- treatments so they do not interfere with species’ life tion must be conducted to detect the presence of fauna associated with the lined cycles trees that are to be treated. Where there is an emergency and where breeding of protected birds and bats has been detected, the Generalitat of Catalonia’s Cos d’Agents Rurals must be informed of this (consult the list of protected species of native wild fauna in Legislative Decree 2/2008 approving the consolidated text of the Animal Protection Act. Generalitat of Catalonia). birds bats January February March April May Breeding seasons of birds and bats June Bat mating season July Bat hibernation August September October November December Eurasian blue tit (Cyanistes caeruleus) Description/application > The life cycles of species of fauna associat- ed with lined trees must be taken into account. Action should be taken outside the breeding periods for birds and bats (from March to July) and the mating period for bats (from August to October). Attempts must be made to avoid acting on trees where winter bat colonies have been detected. These mammals use several nesting substrates throughout the year. Dur- ing the spring they look for warm shelters for establishing their breeding colonies whereas during the winter they use other shelters for spending the cold season in and establishing their hibernation colonies. (See annexe 2: Biodiversity associated with trees: annual cycle for bats). Common pipistrelle (Pipistrellus pipistrellus). Photo: Sergi Garcia. 10 11 IMPROVEMENT INITIATIVES Diversifying alignment-tree species to protect against vulnerabilities associated with dominant species Passeig de Sant Joan’s lined trees Male house sparrow (Passer domesticus) rearing its young in a hollow. Parc de la Ciutadella. Description/application > We need to highlight the ecological role they play as the city’s green-space connec- > Barcelona City Council has a plant-species diversification programme whose tors, as nesting substrates for finches (mainly goal is for no species of alignment tree to exceed 15% of the city’s total number goldfinches, greenfinches and serins) provid- of trees by 2062. The aim here is to prevent the presence of dominant species ing branches for them to build their nests be- from attracting pests or diseases or to prevent any other environmental change tween during the spring and offering hollows, from being able to adversely affect the city’s tree heritage. when the trees are old and large, that are occu- pied by house sparrows (Passer domesticus), > With lined trees, the interests of the actual trees are often limited by the great tits (Parus major), common well gecko physical features of their replacements and make pruning work essential if such (Tarentola mauritanica), lizards and also bats, trees are to coexist with the city. Note here the importance of selecting species of among other animals. lined trees and shape pruning so trees can adapt to their available spaces. 12 13 IMPROVEMENT INITIATIVES Selecting species of trees to improve the quality of the The adult females of this butterfly look for There are many examples which demonstrate southern nettle trees to lay their eggs on, so this relationship between native flora and fau- habitat their larvae can feed off their leaves. Common na, although species do adapt over time and hawthorns (Crataegus monogyna) are also make use of the resources that the alien spe- a host plant for a lovely species of butterfly, cies offer them. It is well known, for example, scarce swallowtails (Iphiclides feisthamelii). that a large number of birds, including war- blers, feed on the fruit of glossy privets (Ligus- trum lucidum) and that blackbirds incorporate the seeds of Japanese mock oranges (Pitto- sporum tobira) into their diet. Olive trees in Parc de la Trinitat Parc del Laberint d’Horta Description/application Scarce swallowtail The criteria for selecting species of trees depend on numerous factors. Some of (Iphiclides these are general criteria, such as climate, environment, sustainability, coexist- feisthamelii). Photo: Wikimedia ence, durability and permanence; others relate more to the trees’ actual biolo- gy (consult the Depart of Green Spaces and Biodiversity’s Manual for managing street trees). Special attention to certain selection criteria is required here in or- der to boost the associated biodiversity: > Native species have to be planted, as they allow greater interaction with local fauna. These include, to name but a few examples, olive trees (Olea europaea), holm oaks (Quercus ilex), Aleppo pines (Pinus halepensis), downy oaks (Quercus pubescens), sweet bay trees (Laurus nobilis), wild cherry trees (Prunus avium), pomegranate trees (Punica granatum), white mulberry trees (Morus alba) and southern nettle trees (Celtis australis), the latter being the host plant of nettle tree butterflies (Libythea celtis). 14 15 > Fruit-producing species that are useful for fauna need to be boosted. Nettle > Species that produce flowers which are attractive to pollinating insects must trees, holm oaks and oaks, blackthorns, common hazel trees etc., and fruit-bear- be boosted. Trees such as field maples (Acer campestre), Montpellier maples ing trees in general, offer fruit that is used by the city’s birds. Nettle trees and (Acer monspessulanum), common hawthorns (Crataegus monogyna), olive trees their fruit are used by a whole range of birds, including blackcaps (Sylvia atricap- (Olea europaea), wild cherries (Prunus avium), cherry plums (Prunus cerasifera) illa), blackbirds (Turdus merula), song thrushes (Turdus philomelos) and Europe- and large-leaved lime trees (Tilia platyphyllos) present flowers containing nectar an robins (Eritachus rubecula), to name but a few, as well as small mammals, as a and high levels of pollen, which are at the disposal of pollinating insects. source of food. It is therefore a good example of a tree that has adapted perfectly to the city and which offers us, moreover, interactions with local fauna, thereby increasing the complexity of habitats. Even so, the suitability of this criterion has to be assessed in some cases, especially where lined trees are concerned and where their fallen fruit requires extra cleaning work. In such cases, we can opt to plant these species in parks and gardens. Parc del Laberint d’Horta Silver lime tree (Tilia tomentosa) in Parc del Laberint Judas trees (Cercis siliquastrum) in Plaça Joanic d’Horta > Species of trees with well-developed boughs need to be boosted, for use as a nesting substrate for goldfinches (Carduelis carduelis), greenfinches (Cardu- elis chloris) and serins (Serinus serinus), among other birds, where the size of the site so allows. Note, however, that small and average sized species present- ing dense foliage, such as callery pear trees (Pyrus calleryana) or oriental cherry trees(Prunus serrulata), to give but two examples, can also be used for nesting. Common hawthorns (Crataegus monogyna) and blackthorn (Prunus spinosa) fruit Plane trees along Carretera de Montjuïc’s Holm oaks along Avinguda Diagonal > Ruling out the use of invasive species which pose a risk of undermining near- by natural spaces, owing to their ability to propagate and re-sprout. An example are black locusts (Robinia pseudoacacia) and trees of heaven (Ailanthus altissi- ma). Consult the Study on invasive species in Barcelona and the proposal for al- ternative species on the City Council’s website. 16 17 IMPROVEMENT INITIATIVES Pruning needs to be made compatible with the > Avoiding heavy pruning, wherever possi- ble, as this weakens trees and prevents large presence of fauna to foster biodiversity boughs from developing that are used by many birds. Such pruning may only be used where necessary and for reasons of public safety. It Tawny owl (Strix aluco). is true, however, that such heavy pruning (lop- Parc de les Corts ping and dividing-up) has led to a large num- Photo: David Garcia. ber of hollows that birds such as sparrows and tits readily use for building their nests in. In any case, such continued pruning has ended up affecting the vigour of trees and their ca- pacity to compartmentalise the cuts that are caused. Plane trees > in Parc de la Monk parakeet (Myiopsitta monachus) is a species indigenous to South Amer- Ciutadella. ica which, as a result of accidental or deliberate releases and its great capacity for adapting to our environment, has reached high population levels, with some 5,000 in Barcelona (data from the Barcelona Public Health Agency in 2015). Using several substrates for nesting, adapting to several types of food, highly success- ful breeding and a lack of natural predators are just a few of the factors that explain this species’ high population level. Description/application > Where green pruning is carried out during the breeding period (spring), special care has to be taken to detect nests on boughs or in hollows and cracks where birds and colonies of bats and squirrels can shelter. (See annexe 2: Biodiversity associated with trees). Barcelona City Council is currently preparing an internal procedure that proposes putting a halt to pruning work where nests occupied by birds are ob- served. Where necessary, signage can be put up in- forming citizens of the reasons for halting the work. Monk parakeets (Myiopsitta monachus) Monk parakeet nest on a date palm tree Work removing monk parakeet > During the winter campaign, attention needs to feeding in the grass. (Phoenix dactylifera). (Phoenix dactylifera) nests. be paid to the presence of cracks and hollows in for- est, park and garden trees that may contain colonies of bats, given their use of such substrates for hiber- Royal Decree 630/2013 includes monk parakeets in its Spanish catalogue of ex- nation. It is true, however, that most bats in Barcelo- otic invasive species, so a suitable form of management has to be studied and na during this time of the year usually look for shel- planned to reduce their population levels. ter outside the city for hibernation purposes, such as deep and isolated hollows with little variation in temperature. Common magpie nest (Pica pica). 18 19 IMPROVEMENT INITIATIVES Managing woodlands to create mature urban forests > It is therefore recommended that forests are managed so they have larger trees, with a diverse range of tree species and a good vertical vegetation struc- ture, so that the herbaceous, shrub, lianoid and tree layers are well represented. Parc del Laberint d’Horta’s forest Description/application area > The city’s woodlands need to be planned in a way that not only respects nat- ural successions but also promotes the presence of mature urban forests that meet the habitat requirements for many of the various species of fauna. The for- est’s maturity results from the ageing dynamics of its tree cover, which are as- sociated with a series of processes, such as the shaping of hollows, closing of boughs and opening up of clear spaces, caused by disturbances to the environ- ment and the decomposition of dead wood. Photo: Andrés Flajszer 20 21 IMPROVEMENT INITIATIVES Leaving dead trees standing to boost biodiversity > A dead tree of a certain size that remains standing is used as a feeding substrate for many species of insectivorous birds and, also, as a breeding substrate for several species Dead tree in the that occupy tree hollows. Species such as Eu- Jardins del Mas ropean green woodpeckers (Picus viridis) and Ravetllat the great spotted woodpecker (Dendrocopos major) choose dead and branchless trees for carving out their nests, as they present a soft- er texture. Woodpeckers are territorial birds that usual- ly change their nests every year and therefore leave behind a series of hollows at the dis- posal of other species of birds, such as the great tit (Parus major), the Eurasian blue tit (Cyanistes caeruleus), the European crested tit (Lophophanes cristatus) and the short-toed treecreeper (Certhia brachydactyla) but also some species of bats and squirrels (Sciurus vulgaris). Old woodpecker nests are becom- ing more important in young forests and pine European green woodpecker (Picus viridis). Photo: Wikimedia groves (where fewer hollows are produced than in oaks, holm oaks and poplars). > The recommendation, then, is to choose very specific areas in forest zones off the beaten track where various dead trees can be left standing; access to these areas can then closed off, to prevent any risks to public safety. For these purposes a professional can analyse the possible risks of falling trees and, therefore, the feasibility of such action. It may also be advisable to carry out some reduction pruning on these dead trees and so minimise any risk of falling branches. In any case, this action will provide feeding opportunities for various species of fauna and will enable sev- eral species of birds to carve out their nests there. Description/application Trees that have died through competition with other trees, ageing, snapping from gusts of wind and other natural causes still have important ecological functions that generate biodiversity. Short-toed treecreeper (Certhya brachydactyla) looking for food on the bark of a Judas tree (Cercis siliquastrum) 22 23 IMPROVEMENT INITIATIVES Managing dead wood to boost biodiversity > It is advisable to ensure the presence of dead wood in forest areas by maintaining what is created naturally. This is a simple measure that does not require any intervention. > Cutting and pruning work can be exploited in young and immature forests lacking dead wood and thereby used to contribute a cer- tain quantity of dead wood that can be uni- formly distributed all over the area acted on, or for accumulating small numbers of trunks. The optimum quantity needed for boosting bi- odiversity is hard to specify. Factors such as quality (degree of decomposition), productivi- ty, depending on the type of forest in question, and climatology are variables that are hard to establish a response to in that respect and which are currently being studied. Decomposed trunk in the Jardí de les Hespèrides Description/application Dead wood provides a habitat for the survival of many species of fungi, mosses and various saproxylic invertebrates (which feed on decomposing dead wood), whose presence is directly connected to this availability of dead wood found in forests. Some of these groups take part in the decomposition processes of organ- ic matter and the recycling of nutrients, while others are also food for groups of fauna higher up the food chain, mainly birds such as woodpeckers, treecreepers and tits, as well as reptiles and mammals such as shrews and hedgehogs. Managing accumulated dead wood therefore helps to generate biodiversity. Quite a separate thing, and with very different effects, are the exceptional disturbanc- es from large-scale falling and dead trees that can pose a risk by attracting forest pests and diseases. We need to make sure the ecosystem’s capacity for process- ing such dead wood is not overloaded. 24 25 IMPROVEMENT INITIATIVES Maintaining tree hollows to boost biodiversity, without > It is therefore advisable to respect the hollows found in forest trees that arise from falls or cut branches, malformations or compartmentation problems, pro- putting public safety at risk vided they do not compromise public safety. Hollow in a Box elder (Acer negundo). Note Description/application the presence of a European common gecko. > The availability and quality of tree hollows is a limiting factor for the fauna that use them as a breeding, refuge and hibernation substrate. Numerous birds, as well as mammals such as bats and rodents, reptiles and many invertebrates (snails, slugs, spiders, cockroaches, moths etc.,) are regular users. > There is strong inter-species competition for better-quality hollows in forest areas with a shortage of hollows. Less competitive species will have to choose poorer-quality hollows, in other words, hollows close to the ground and vulner- able to the predation that comes with them, small-chamber hollows or hollows with entry holes that are too large. It is advisable, therefore, for forest areas to present a large number of uniformly distributed hollows, as many animals switch them from one breeding season to another, to reduce risks of predation or the presence of parasites. Hollow in a plane tree 26 27 IMPROVEMENT INITIATIVES Planting plant species in tree pits to boost the Description/application presence of useful fauna > A good way of boosting biodiversity is to plant useful plant species in align- ment tree pits, especially in areas of the city where biological controls are carried out. Working with plants that offer us extended periods of flowering with a useful nectar-secreting content and which are sufficiently rural to support the pressure of the urban environment will enable us to have a reserve of useful fauna avail- able to tackle tree pests and diseases. (See Urban Allotments. Annexe 1: Useful plants for beneficial fauna). Alfalfa (Medicago sativa) in tree pits, Montjuïc Planting lavender (Lavandula officinalis) in tree pits. Ceràmiques Vicenç Parc de les Rieres d’Horta Tree pit with weeds 28 29 ANNEXE 1 BIOLOGICAL CONTROL IN BARCELONA. Alignment tree Species Pest Natural enemy Effectiveness units treated 5000 Platanus x hispanica Corythuca ciliata Anthocoris nemoralis Average 9200 Styphnolobium japonicum Aphid sp. Aphidius colemani High 2843 Tipuana tipu Platycorypha negrivirga Anthocoris nemoralis Average 4725 Robinia pseudoacacia Aphid sp. Aphidius colemani High 2927 Cercis siliquastrum Cacopsylla pulchella Anthocoris nemoralis High 2673 Jacaranda mimosifolia Aphis gossypii Aphidius colemani High 1407 Tilia sp. Eucallipterus tiliae Aphidius colemani High 933 Catalpa bignonioides Aphid sp. Aphidius colemani High 911 Hibiscus syriacus Aphis gossypii Aphidius colemani High Total 30619 Data from the Tree Management Department in 2014. Green Spaces and Biodiversity Department. Barcelona City Council Aphid (Aphis catalpae) next to a ladybird larva on a catalpa leaf. Photo: Xelo Ribes Biological control for tackling the sycamore lace bugs (Corythuca ciliata) 30 31 ANNEXE 2 BIODIVERSITY ASSOCIATED WITH TREES: TREECREEPERS AND TITS These are all insectivorous birds incapable of carving out nests in tree trunks and are therefore de- BIRDS AND MAMMALS pendent on old woodpecker nests and other hollows that trees offer them to nest in. WOODPECKERS Woodpeckers (Picidae family) are a group of birds that feed on trunks and branches (often on dead SHORT-TOED TREECREEPER (Certhia brachydactyla) wood) and which build their nests by piercing trees with their powerful beaks. They can be observed scaling trunks and branches, although some species also go down to the ground in search of food. Features: this is a brownish-colour bird whose distinctive trait is its fine, The main species of woodpecker we can observe in forest areas on the southern slope of the Collse- very long and slightly curved beak. Also notable are its toes, especially rola mountain are European green woodpeckers (Picus viridis). Note too the modest incursion that the back one, which is longer and used for getting a firm grip on tree great spotted woodpeckers (Dendrocopus major) seem to have been making in the Parc del Laberint trunks. d’Horta over the last few years. Habitat: it lives in every type of forest - including oak, pine and riparian woodlands - as well as in Barcelona’s parks and gardens, provided there EUROPEAN GREEN WOODPECKER (Picus viridis) are old, rough-barked trees for searching for food on. Features: This is a large build, some 30 cm long, notable for its green- Feeding: every kind of insect and spider. ish-coloured plumage. A red stripe appears on the crown of its head. It also has a moustache-shaped stripe with a red centre in males and a Behaviour: Presents a fairly curious form of food-searching behaviour, Photo: Wikimedia black centre in females. which it does between the bark and cracks of trunks, using its beak to capture food, starting from the bottom of the trunk and progressing upwards in helical movements Habitat: this is an ubiquitous species that occupies a large variety of all along the trunk. Once it has covered the entire main trunk, it flies down to the base of another tree habitats, from mature forests to open spaces with trees. The spe- nearby trunk. cies prefers forests that have dead wood available and trees with softer wood for carving nests in, as it is not a good nest piercer. It accordingly Nest: it uses cracks and holes in tree trunks to house its nests, which are made of grass, roots, piec- prefers to carve out holes in weakened or dead Aleppo pine trees (Pinus es of bark and feathers. It also occupies old European green woodpecker nests. halepensis) or trees with soft wood, such as poplars (Populus nigra) and aspens (Populus tremula). Distribution: it is sedentary and nests in Catalonia. Photo: Wikimedia Feeding: it feeds on a large quantity of insects it captures with its long and sticky tongue. It shows a predilection for ants and their larvae and eggs, although it also eats fruit and seeds. It often looks for food on the ground. Behaviour: it has a characteristic sway to its flying and gives out a call that sounds like laughter. Its beak can be heard tapping away against trees, to carve out a nest, in the months of March and April. They usually change their nests every year. Nest: entry holes to nests are some 6 cm in diameter. Distribution: it is sedentary and nests in Catalonia. 32 33 TITS Tits (Paridae family) are small insectivorous forest birds that feed mainly from tree boughs, al- EURASIAN BLUE TIT (Cyanistes caeruleus) though some species feed from among shrubs and the ground too. They use a large variety of hol- lows for breeding and live in different environments. Even so, each species of tit has a preference for Features: its tail, wings and crown are blue. It has a black stripe that a particular type of forest. The European crested tit (Lophophanes cristatus) and coal tit (Periparus crosses its eyes from the base of its beak to the back of its neck. Its ater) live in pine forests, whereas the Eurasian blue tit (Cyanistes caeruleus) prefers oak, holm oak cheeks are white. Its chest is yellow with a small longitudinal black or mixed forests. The great tit (Parus major), by contrast, is the most generalist of all and can live in stripe. any type of forest. Habitat: it shows a preference for mixed or deciduous open woods, as found in Barcelona’s parks and gardens. Feeding: it feeds on insects and their larvae, spiders and even eats Photo: Guillem Pascual fleshy fruit. GREAT TIT (Parus major) Nest: it usually nests in tree hollows, although it normally nests in other substrates in urban set- Features: a bird that is unmistakable, thanks to the spectacular tings, such as stone walls. It builds its nests from moss and feathers. It will live in a nest box where black strip that runs down its yellow chest and which is identifiably there are few holes and where entry holes have diameters measuring 27 mm. wider among males than females. Distribution: it is sedentary and nests in Catalonia. Habitat: it is the most generalist species of the family when it comes to habitat, although it does show a preference for forests that are not dense. The species can be seen in Barcelona, not just in its parks and gardens but also in its more urban areas, where there are ma- Photo: Pau Núñez ture lined trees with available hollows. Feeding: it feeds on insects, especially cockroaches and spiders, as well as fruit in the winter. It also EUROPEAN CRESTED TIT (Lophophanes cristatus) includes pine processionary (Thaumetopoea pityocampa) caterpillars in its diet. Features: it bears an unmistakable crest on its head which rises or drops Behaviour: its females apparently tend to mate with males that present plumages that are more when it is defending its territory or in a state of alert. spectacular in tone and intensity, which are indicators of a better quality diet and, therefore, of be- ing in better health. Habitat: it shows a preference for pine forests. Nest: it builds nests in the shape of a small pot, made from moss, branches, down and other ele- Feeding: it feeds on insects and spiders and supplements its diet with ments that the adults find, such as hair and wool threads, and places them in tree hollows or holes pine nuts outside the breading season. It stores its food in tree-bark in stone walls. It readily accepts nest boxes with 30 mm wide holes (larger than the ones that the cracks. Eurasian blue tit uses). Nest: it nests in tree hollows and builds its nests from hair, wool and Distribution: it is sedentary and nests in Catalonia. feathers. It is a regular inhabitant of nest boxes, where they have entry Photo: Wikimedia holes measuring 28 mm in diameter. Distribution: it is sedentary and nests in Catalonia. 34 35 OWLS COAL TIT (Periparus ater) This is the generic name for a group of nocturnal birds of prey that feed on small insects, micro- mammals and small birds. Notable owls in the city’s woody areas include: Features: its head is black while the back of its neck and its cheeks are white. Habitat: it can be seen in the woody areas of the city’s parks and gardens, especially where there are pine trees. EURASIAN SCOPS OWL (Otus scops) Feeding: it is basically an insectivore that feeds on small cockroach- Features: this is a small owl which, thanks to its mimetic brown- es, wasps, bees and spiders, through it also eats pine seeds during Photo: Wikimedia and grey-shaded plumage, is quite hard to spot. the autumn and the winter. Its fine beak allows it to forage for food between pine needles and pine-cone scales, often with acrobatic twists and turns. It stores its food Habitat: it can be found in different environments ranging from agri- during the autumn in the tree-bark cracks, old nests, holes and other places, for use when there is cultural plains, mosaic spaces and forest areas. It nests in tree hol- a sharp fall in the quantity of food resources during the winter. lows and uses old woodpecker nest hollows. Nest: it builds its nests out of moss, hair and feathers in tree hollows and holes in stone walls. It can Feeding: it feeds on insects. also use nest boxes where their entry holes have 25 mm diameters. Distribution: it is active in the summer and nests in Catalonia. Distribution: it is sedentary and nests in Catalonia. Photo: Wikimedia LONG-TAILED BUSHTIT (Aegithalos caudatus) TAWNY OWL (Strix aluco). Features: it has a small, round body with a disproportionately long, Features: this is an average-sized owl, with varied colouring, rang- black and white tail. ing from grey to reddish brown. In fact, its plumage goes through grey and red stages. It has black eyes. Habitat: it lives in woody and shrubby areas and fruit-tree fields. Habitat: this is a nocturnal bird of prey that breeds and hunts mainly Feeding: it eats insects, spiders and seeds. in the forest, though it also uses nearby open spaces for hunting. It breeds in mixed or deciduous forests, such as oak woods, large Nest: it builds its nests from lichens, moss and cobwebs and usually parks and gardens and avenue-aligned trees that offer suitable hol- Photo: Lluís Maria Güell lines them with feathers. Its nests are balloon shaped with a small lows. It can be seen in the evenings and, sometimes, while it rests Photo: Wikimedia lateral entrance hole. It nests in shrubs and trees. during the day, perched on a branch, as shown in the photo here taken of one on a glossy privet (Li- gustrum lucidum) on Carrer de Verdi. Distribution: it is sedentary and nests in Catalonia. Feeding: it feeds mainly on small mammals (wood mice, shrews etc.,) and therefore plays a key role in regulating the populations of these animals. Even so, the species presents a relatively varied diet that includes small birds, frogs and various invertebrates. Distribution: it is sedentary and nests in Catalonia. 36 37 TREE-CROWN BIRDS Also worth noting are finches, a family of small Notable species we can find associated with trees include a whole series of forest birds that breed birds with spectacular calls and plumage and and feed in tree crowns, which provide them with the food they need: fruit, seeds and invertebrates. which often nest in Barcelona’s ornamental The following are examples of this group: wood pigeons (Columba palumbus), Eurasian collared lined trees. They are granivores, that is, they doves (Streptopelia decaocto), common firecrests (Regulus ignicapillus) and common chaffinches feed on the grain and seeds of herbaceous (Fringilla coelebs). They all nest among the branches of trees or tall shrubs and build their nests plants from open spaces. Though they are as- from small branches in the shape of a pot, the sizes of which vary according to species. These forest sociated with open spaces, they can easily be birds are mainly insectivores, although fruit and seeds make up an important part of their diet dur- seen and their calls heard in the city’s parks ing the autumn. Such is the case with the Eurasian jay (Garrulus glandarius), another typically forest and gardens. The European goldfinch (Cardu- bird, easy to spot and, above all, listen to as it gives out a characteristic alert call when a person elis carduelis), the European greenfinch (Car- approaches its territory. It belongs to the corvid family and has the distinctive habit during the au- duelis chloris) and the European serin (Serinus tumn of burying acorns and other fruit in the land, creating small food reserves, that allow them to serinus) are just a few of the species that can face the cold season when food is scarce. It does not always remember its food stores and therefore be seen nesting in the crowns of trees of all acts as a fruit-dispersing agent. European serin (Serinus serinus). sizes. They can be seen in the winter, feeding Photo: Xavier Ferrer from the city’s urban and peri-urban pasture, often forming fairly large groups. European greenfinch (Carduelis chloris). Photo: Wikimedia Wood pigeon (Columba palumbus). Photo: Xavier Ferrer Male common chaffinch (Fringilla coelebs) Eurasian collared dove (Streptopelia Jay (Garrulus glandarius). Photo: Wikimedia Common firecrest (Regulus ignicapilla). Photo: European goldfinch (Carduelis carduelis). Photo: decaocto) Wikimedia Wikimedia 38 39 TREE-ROOSTING BATS OTHER MAMMALS ASSOCIATED WITH TREES COMMON PIPISTRELLA (Pipistrellus pipistrellus). SQUIRREL (Sciurus vulgaris) This is a fissure bat, as it seeks refuge in every kind of crack in houses, rocks, trees etc. It is com- Features: also associated with trees are squirrels(- monly found in houses, behind shutters, roof tiles and rain pipes. It likes to hunt in woods, shrubby Sciurus vulgaris), which are tree-dwelling and active areas, parks and urban zones where it is frequently seen flying at night under the city’s park and during the day. garden lamp posts. It is one of Europe’s smallest bats, weighing between 4 kg and 7 kg. Habitat: pine forests. Feeding: it basically feeds on fruit and seeds, with pine nuts as its staple diet. Note here the role played SOPRANO PIPISTRELLE (Pipistrellus pygmaeus) by Aleppo pines (Pinus halepensis) as a large pro- ducer of pine nuts (practically throughout the year) This is a fissure bat found in all types of buildings that can also easily be seen hunting small insects which have a high caloric value. in parks and gardens, especially where there are ponds and pools. It is more usually found in the Photo: Josep Piqué city than the common bat. It usually shelters not just in building cracks and fissures but also tree Behaviour: with a bit of luck you can catch sight of a hollows where they hibernate. squirrel scaling a tree trunk or jumping from branch to branch. What is easy to find are the traces of gnawed pine cones that allow them to feed on their pine nuts. It is worth knowing, however, how to distinguish pine cones that have been gnawed at by squirrels and wood mice (Apodemus sylvaticus), respectively. Where a cone is found with threads and a large number of scales around it, it’s been nibbled by a squirrel. By contrast, if the entire cone has been KUHL’S PIPISTRELLE (Pipistrellus kuhlii) gnawed at and no threads are left, the culprit is obviously a wood mouse, as it eats not only the pine nuts but also the scales. It prefers to hunt in spaces full of trees or by street lamps, where many insects are attracted by their light. During the summer it shelters and breeds under tree bark, in tree hollows and cracks in Nest: it builds spherical nests, covered in branch- buildings. es, leaves, moss and hair, which it positions on the branches of large trees. Distribution: it can be seen in Barcelona on the pine trees in the rosengarden at the Parc de Cervantes, in > Annual bat cycle the Jardins del Palau de Pedralbes, in the Parc del Bats have an annual cycle that corresponds to the availability of food (insects) in the environment Putget, in the Parc del Castell de l’Oreneta and in the they develop in, and to the seasons. Males and females shelter temporarily in the autumn to mate. The Laberint d’Horta. female normally keeps its mate’s sperm until the following spring, to start the process of gestation. During the winter, bats seek hibernation shelters where they will remain inactive for a long time. Bats leave their winter shelters during the spring, when temperatures start to rise. Females start moving Pine cones gnawed at by wood mice (Apodemus sylvaticus) to breeding or summer shelters, sometimes stopping at temporary shelters until they have located a final one for breeding. It is then that the ovule is fertilised and pregnancy begins, lasting between six and eight weeks. Males do not take part in the breeding process. The cycle starts again in the autumn. January February March April May June July August September October November December Winter shelters Temporary shelters Summer shelters 40 41 INDEX INTRODUCTION 44 CONSERVATION INITIATIVES Conserving the understorey 46 Conserving the natural size of shrubs 48 Restricting the use of invasive plants 50 Restricting the use of resinous species 52 IMPROVEMENT INITIATIVES Boosting the use of native species of flora 54 Boosting the presence of litterfall and other fauna shelters 60 A dapting maintenance work to the natural cycles of flora and fauna 62 Creating mixed hedges 64 Hedge vegetation 66 ANNEXE 1 List of invasive species 68 ANNEXE 2 Understorey birds and mammals 70 ANNEXE 3 Shrubby plants of use to fauna 76 Shrubby scrubs of use to fauna 78 ANNEXE 4 Shrub fruiting calendar 80 Climber-plant and hedgerow fruiting calendar 80 43 SHRUB GROUPS AND HEDGES INTRODUCTION Shrubby vegetation is typical of the Mediterranean region and very common in our country. It currently occupies over 400,000 hectares in Catalonia, according to data from the Department of Territory and Sustainability. This makes it the third-largest type of habitat, after (i) agricultural land and anthropogenic are- as and (ii) coniferous forests. Shrubs are not usually over five metres high and their height can vary considerably. In fact, the types of shrub vegetation found are fairly diverse (scrublands, garrigues and maquis) and each has its own dis- tinctive features. So, for example, scrubland covers the ground less when com- pared to maquis, which is denser. Bramble patches present more vertical devel- opment than scrublands. Shrub vegetation is found everywhere in urban areas, in squares, streets, parks and gardens, in all its varieties; such vegetation appears everywhere, for ornamental use — a prime example are rose bushes — but also for marking paths or separating spaces, whether in a park or on a public street. A clear example of this latter function — which coexists with the ornamental — are the hedges that can be seen along major avenues, such as Gran Via. Authentic habitats There are functions typical of a habitat besides the ones mentioned above. From this point of view, strengthening the shrub layer in parks and gardens has a direct impact on biodiversity. Besides providing a better structure and enriching the landscape mosaic, shrub vegetation acts as a green-area connector and offers nesting, sheltering and feeding places for insects and other invertebrates, small birds and mammals. It is precisely this large quantity of shrubs in the city which makes their contribution to biodiversity so important and, therefore, comparable to the role played by trees. Because of its diversity, shrub vegetation allows numerous aesthetic combina- tions with contrasting forms, colours and aromas. Such combinations may also make places attractive to fauna. Rows or hedges made up of a single species are less attractive in that respect, but this can be compensated for with the intro- duction of fleshy-fruit species. For the general purposes of boosting biodiversity, it is advisable to avoid making spaces uniform and always ensure their potential for good diversity. Firm but flexible criteria Parc del Turó del Putxet Taking full advantage of the contribution made by shrubby groups and hedges to biodiversity requires the establishment of firm criteria for the organisation of their maintenance and improvement. However, such criteria have to be suf- ficiently flexible to adapt to the requirements of each space and species, given the heterogeneity of this plant group. Biodiversity as a goal is compatible with achieving environments with contrasting colours and aromas. A management of shrubby groups that takes account of all these aspects will enrich the urban en- vironment all the more. 44 45 CONSERVATION INITIATIVES Conserving the understorey to boost biodiversity and > It would be useful to carry out thorough scrub-clearing in the area of influence of biological connectivity these parks and gardens frequented by wild boars (Sus scrofa) and subject to the effects of their rummaging, for the purposes of re- moving the environment’s shelter-providing shrubby cover and making it more difficult for such fauna to move to the gardened areas. Likewise, for the purposes of fire protection and regulation compliance (Decree 123/2005), a 25-metre buffer strip has to be kept clear along the boundary between the city and Parc de Collserola. Where there is a risk of fire, the number of more inflammable woody species must be reduced, including species of rockrose (Cistus sp.) and heather (Erica sp.) and generally all the spe- cies that contain essential oils and other vola- tile and inflammable compounds. By contrast, we have to boost the presence of dense-wood and high-heat capacity species that need to absorb considerable heat before they can Heather (Erica multiflora) catch fire, such as boxwood (Buxus semper- virens), mastic trees (Pistacia lentiscus), tur- pentine trees (Pistacia terebinthus), Mediter- Parc del Laberint d’Horta’s understorey ranean buckthorn (Rhamnus alaternus), black hawthorn (Rhamnus lycioides), flax-leaved Description/application daphne (Daphne gnidium), laurustinus (Vibur- num tinus), Kermes oak (Quercus coccifera), Made up of herbaceous and shrubby species, the understorey provides fauna common juniper (Juniperus communis), straw- with places for nesting, sheltering and feeding. It also plays an important ecolog- berry trees (Arbutus unedo), osyris (Osyris ical role, as it makes it easier for fauna to move about. alba) and other shrubs. > Understoreys do not generally have to be removed from forest spaces. Where > One-off clearing and pruning, as well as a space presents considerable cover and action is decided on, selective pruning selective cutting, should preferably be carried can be carried out from time to time, respecting a certain number of stems from out during the winter and always avoid the Cistus clusii the various shrub and liana species, so that the shrub layer is reduced to 30% or nesting period of birds (spring). Consult Act 40% (as a maximum) and to a height between 1 and 2 metres. The shrubby struc- 5/2003 on the prevention of forest fires, im- ture is therefore guaranteed. Sections are made stem by stem, so that the woody plemented under Decree 123/2005. understorey is uniformly distributed throughout the area acted on. In any case, stronger pruning can concentrate on places with higher levels of human activity (beaten paths etc.) Fruit-bearing species need to be boosted. 46 47 CONSERVATION INITIATIVES Conservation of the natural size of shrubs to boost > Enhancement pruning has to be avoided. the fauna’s shelters and nesting Evergreen spindle (Euonymus japonicus) > Heavy pruning must be avoided. Laurustinus (Viburnum tinus). Pl. Gal·la Placídia Description/application > Enhancement pruning must be avoided to ensure shrubs maintain their natural sizes. Where these shrubs are located in walking areas or flower beds in which accumulated rubbish can be seen, one option may be to enhance the first line of shrubs and thereby make cleaning work easier. Strawberry tree (Arbutus unedo) 48 49 CONSERVATION INITIATIVES Restricting the use of invasive plants to prevent Account should also be taken of the invasive potential of certain species which, while not listed as invasive plants, behave as such in certain places. Such is the them from spreading in ecosystems case with Japanese mock orange (Pittosporum tobira) in Parc de Collserola. Their seeds feed song thrushes (Turdus philomelos), common blackbirds (Turdus mer- ula) and other birds that act as seed-dispersing agents and contribute to the spread of the species through natural areas. We therefore need to avoid planting Japanese mock oranges and other plant species with invasive potential along the Barcelona buffer strip bordering the Parc de Collserola. Japanese mock orange (Pittosporum tobira) Description/application Consider the list of invasive plants. (See annexe 4: Study on invasive species in Barcelona and proposal for alternative species) when it comes to taking deci- sions on renovating or creating a plantation. Some of these plants are listed in the Spanish catalogue of exotic and invasive species (Royal Decree 630/2013). Such is the case with summer lilac (Buddleja davidii) which, given its capacity to re-shoot and grow and ease of dispersal through seeds, creates problems onriver banks in many places. It is true that summer lilacs attract a large number of but- terflies due to the high content of their flowers, though their invasive behaviour and negative effects on natural communities must not be forgotten in any case. Summer lilac (Buddleja davidii) 50 51 CONSERVATION INITIATIVES SHRUB GROUPS AND HEDGES Restricting the use of resinous species to avoid acidifying the soil Mediterranean Accumulation of pine needles cypress hedge (Cupressus sempervirens) Description/application Restricting, in hedges or groups of shrubs, the presence of resin-producing spe- cies (cypresses and other conifers), which excessively acidify the soil and pre- vent the development of invertebrates among the litterfall. Mastic tree hedge (Pistacia lentiscus) Northern white- cedar hedge Thuja occidentalis 52 53 IMPROVEMENT INITIATIVES Boosting the use of native species of flora to attract >Strengthening the presence of birds: through fruiting, during a period in the year Shrubs or hedgerows have to be chosen which when there are few food resources. (See an- local fauna bear fruit during the autumn-winter period, nexe 4: Fruiting calendar). At the same time, such as strawberry trees (Arbutus unedo), birds act as seed-dispersing agents of these mastic trees (Pistacia lentiscus), laurusti- types of fleshy fruit and therefore play an eco- nuses (Viburnum tinus), elmleaf blackberry logical role of the first order. So, blackbirds shrubs (Rubus ulmifolius), dog rose bushes (Turdus merula) and robins (Erithacus rubec- (Rosa canina), evergreen rose bushes (Rosa ula), for example, are seed-dispersal agents of sempervirens) and sweetbriar rose bushes ivy, whose fruit constitutes a large part of their (Rosa rubiginosa). The peak maturation period winter diet. for these plants is during the autumn and win- ter, marking the arrival of migrant and winter Understorey birds refer to a whole series of birds, which have high energy requirements species that move through this shrub layer for tackling long migration periods and low and use it for hiding their nests in and feeding temperatures. This fosters the availability of on every type of invertebrate and fruit offered food for fruit-eating birds and many insecti- by the various species of shrubs and lianas vores which change their diet during the cold found there. These notably include Sardinian season when low temperatures prevent the warblers (Sylvia melanocephala), blackcaps development of invertebrate species. All these (Sylvia atricapilla), Eurasian wrens (Troglo- fruits will be used by blackbirds, thrushes, dytes troglodytes), European robins (Erithacus robins, warblers and flycatchers. This is there- rubecula) and blackbirds (Turdus merula). (See fore about offering possibilities of feeding, annexe 2: Understorey birds and mammals). Can Mestres Description/application Hedges are usually made up of species such as cherry laurels (Prunus laurocera- sus), evergreen spindle (Euonymus japonicus), Atlantic white cedar (Thuja orien- talis), Japanese mock orange (Pittosporum tobira) and other shrubs often used in gardening for their dense and persistent foliage and resistance to frequent prun- ing. Even so, and as far as the associated biodiversity is concerned, it can be ge- nerically asserted that using native plant species allows greater interaction with a space’s local fauna, so increasing the complexity of the ecosystem or habitat. Irrespective of the species used, the shrubby Parc del Laberint d’Horta Elmleaf blackberries (Rubus ulmifolius) Butcher’s-broom fruit (Ruscus aculeatus) Male blackbird (Turdus merula) structure is an important factor in its own right that has to be taken into account, as it offers nesting places for understorey birds, tree cover for the movement of fauna and litterfall accumu- lation areas. European robin (Erithacus rubecula). Photo: Male and female Eurasian blackcaps (Sylvia atricapilla). Photo: Wikimedia Wikimedia 54 55 >Strengthening the presence of butterflies: >Strengthening the pollinating insects: The false ilex hairstreak (Satyrium esculi) uses the Cleopatra butterfly (Gonepteryx cleopatra) Kermes oak (Quercus coccifera) the holm oak (Quercus ilex) as its host plant Native shrubs have to be used, as a host plant for several species of butterflies. Strawberry trees (Arbutus unedo), for example, attract two-tailed pashas (Charax- es jasius), one of the most spectacular of our fauna and considered Europe’s largest diurnal butterfly. A fluorescent green crossed by a lateral yellow line on both sides of the body and a head with four horn-like protuberances are the hallmarks of its caterpillar, which feeds exclusively on strawberry tree leaves. The Mediterranean buckthorn (Rhamnus alaternus) is another example of shrub that is used as a host plant for the Cleopatra butterfly (Gonepteryx cleopatra) and the common brim- stone (Gonepteryx rhamni). (See Courtyards, small gardens, balconies, terraces and green roofs. Annexe 2: Diurnal butterflies). Elongated bean weevil (Lixus algirus) Grey-leaved cistus (Cistus albidus) Collserola allotment Laurustinus, rosemary and lavender. Hummingbird hawk-moth (Macroglossum stellatarum) sipping from lavender flowers Two-tailed pasha adult and caterpillar Strawberry tree flowers and fruit (Arbutus (Charaxes jasius). Photo: Wikimedia unedo) 56 57 >It is also advisable to boost shrub layers in the periphery of parks and gardens as feeding and shelter places and as green-area connectors, using high-value ecological and perhaps less aesthetic species. Bramble bushes deserve special attention, often little appreciated and at the wrong end of maintenance work, but very useful given that they bear fruit and shelter insects and invertebrates in general, as well as understorey birds and mammals, such as the common or European hedgehog (Erinaceus europaeus). Boosting the presence of species in green areas, such as elmleaf blackberries (Rubus ulmifolius), means working to- wards a better structure of the landscape mosaic, by ensuring, at the same time, shelter and food for many groups of fauna. Flowering sweet bay tree (Laurus nobilis) Flowering laurustinus (Viburnum tinus) Flowering common dogwood (Cornus sanguinea) Use will be made of plants such as rockrose (Cistus sp.) and shrubby hare’s ear (Bupleurum fruticosum) and aromatics such as thyme (Thymus vulgaris), rose- mary (Rosmarinus officinalis) and lavender (Lavanda officinalis), whose high nec- tar-content flowers coat pollinating insects with large amounts of pollen. Rose bushes (Rosa sp.) are also very attractive to fauna, especially when they are wild species bearing simple rather than double flowers, as they provide pollinating insects with access to the flowers’ nectar. (See Grasses, fields and grasslands. Annexe 3: Beekeeping flora). Their fruit provides food for birds. Palau Reial’s shrubby area Dog-rose (Rosa canina) flower and fruit Bramble bushes in the Can Cadena’s allotments 58 59 IMPROVEMENT INITIATIVES Boosting the presence of litterfall and other fauna >Shrub-pruning needs to be carried out in more remote forest areas, to build up small shelters to boost biodiversity piles of trunks, branches and litterfall, one or two metres in diameter and roughly one metre in height. Such accumulations will be distributed throughout the area acted on at a density free of fire risks. Shelters and feeding places are thereby created for invertebrates, wood mice (Apodemus sylvaticus) and other small mammals, such as the common or Eu- ropean hedgehog (Erinaceus europaeus) and understorey birds, by making up for the loss of understorey wood. It is also advisable to put empty trunks or stones between shrubby vegetation, creating holes and spaces inside them. Cross spider (Araneus diadematus), commonly found in gardens Description/application >It is advisable not to remove litterfall from less visited garden areas, so invertebrate fau- na can develop. Note that invertebrates are at the bottom of the food chain and therefore play a key role in enabling insectivores to feed. They also help to incorporate organic material into the soil, by closing the cycle of elements. >Shrub borders require mulching so habitats can be created for invertebrates. 60 61 IMPROVEMENT INITIATIVES Adapting maintenance work to the natural cycles >Entire shrubby areas should not be pruned within the same year, to allow the presence of of flora and fauna to prevent interference in their shrubs at different development stages and development shelter spaces for several species at all times. >Border-maintenance pruning needs to be carried out once a year (between October and February) and shrub shape-pruning just once during the winter period. All these issues can be dealt with under a maintenance plan that establishes the guide- lines that have to be followed in each case and Jardins de Rubió i Tudurí which necessarily have to be compatible with the ornamental criteria for each place. Mastic tree (Pistacia lentiscus) Laberint d’Horta Description/application >The biological cycles of these important shrubs need to be respected, from the per- spective of their fruiting, as they provide food for fauna. >Shrub-group and hedge pruning should be concentrated on during the winter period (from December to February). Otherwise, some birds could be prevented from breeding. The goal is to avoid such pruning coinciding with the birds’ spring nesting season. Pruning Japanese mock orange (Pittosporum tobira) Jardí dels Boixos. Laberint d’Horta 62 63 IMPROVEMENT INITIATIVES Creating mixed hedges to boost biodiversity >If single-species hedges typical of the ones and ongoing pruning do not offer the aesthet- used in gardening are to be created, a shrub ic results expected for such cases. Evergreen species should be considered that is useful for spindle (Euonymus japonicus), Korean privet fauna, such the strawberry tree (Arbutus un- (Ligustrum ovalifolium), shrubby germander edo), the mastic tree (Pistacia lentiscus), the (Teucrium fruticans), cherry laurel (Prunus lau- sweet bay tree (Laurus nobilis) and laurustinus rocerasus), thorny olive (Elaeagnus pungens), (Viburnum tinus). It is important in such cases crimson spire (Escallonia rubra) and others for the associated pruning work to respect the are a good alternative. So, if shrubby hedges flowering and fruiting cycles of the species are to be created with native plants, their nat- used, by making use of a quality shrub layer. ural flowering and fruiting cycles and natural sizes should be respected as much as possi- >Using alien species with a long tradition ble. (See annexe 3: Shrubby plant of use to in ornamental gardening for creating such fauna). hedges is to be preferred in parks and gardens where types and ornamental criteria are as- sociated with thorough pruning-related main- tenance. Native plants undergoing thorough Laurustinus, shrubby germander and mastic- tree shrub border Description/application >Consideration should be given to using several shrubby species for shaping mixed hedges, as they are most like the shrub borders found in a natural wood. Such hedges attract greater diversity of fauna. Coronilla, Limoniastrum monopetalum and laurustinus shrub border. 64 65 IMPROVEMENT INITIATIVES Hedge vegetation for boosting diversity Wall covered with creeping fig (Ficus repens) Minorca honeysuckle (Lonicera implexa) flowers Description/application >Heather and reed dry hedges and even met- al fences can be covered with climbing plants, to make them more useful for fauna. (See an- Wall covered with Chinese wisteria (Wisteria nexe 4: Climber-plant and hedgerow fruiting sinensis) calendar). Minorca honeysuckle (Lonicera implexa) fruit Wall covered with Australian native wisteria (Hardenbergia comptoniana) 66 67 ANNEXE 1 SHRUB GROUPS AND HEDGES LIST OF INVASIVE SPECIES Source: “Study on invasive species in Barcelona and suggestion for alternative species”. Consult the study on the corporate website: http://cort.as/d1YE Scientific name Common name Scientific name Common name Acacia dealbata Silver wattle Lantana camara Wild-sage Acacia saligna Coojong Ligustrum lucidum Glossy privet Acer negundo Box elder Lonicera japonica Japanese honeysuckle Agave americana American aloe Nicotiana glauca Tree tobacco Ailanthus altissima Tree of heaven Opuntia aurantiaca Aloe maculata Soap aloe Opuntia dillenii Araujia sericifera Moth plant Opuntia ficus-indica Prickly pear Arundo donax Giant cane Opuntia maxima Azolla sp. Opuntia stricta Buddleja davidii Summer lilac Parthenocissus quinquefolia Virginia creeper Carpobrotus edulis Hottentot-fig Parthenocissus tricuspidata Boston Ivy Carpobrotus acinaciformis Elands Sourfig Pennisetum villosum Feathertop grass Cortaderia selloana Pampas grass Phytolacca americana American pokeweed Cotoneaster lacteus Milkflower cotoneaster Pittosporum tobira Japanese mock orange Cotoneaster pannosus Silverleaf cotoneaster Prunus laurocerasus Cherry laurel Cylindropuntia sp. Phyracantha angustifolia Narrowleaf firethorn Cyperus involucratus Umbrella sedge Eschscholzia californica California poppy Robinia pseudoacacia Black locust Fallopia baldschuanica Senecio angulatus Creeping groundsel Gomphocarpus fruticosus Milkweed Senecio inaequidens South African ragwort Helianthus tuberosus Jerusalem artichoke Senecio mikanioides Ipomoea indica Blue morning glory Senecio pterophorus 68 69 ANNEXE 2 UNDERSTOREY BIRDS AND MAMMALS EURASIAN BLACKCAP (Sylvia atricapilla) Features: males and females are easily recognised by their re- These are birds and mammals that use shrub layers for finding shelter, nesting spective black and brownish-red crowns (caps). places and food, such as the small invertebrates and fruit they are provided by the various species of shrubs and lianas. Habitat: they live in woody areas that have an abundant shrub understorey. Common too in the city’s parks and gardens. WARBLERS, CHIFFCHAFFS AND WRENS Warblers are the group of birds most directly linked to shrub layers. They carry Feeding: they are insectivores, although they will supplement out most of their activity between the branches of shrubs and bramble bushes, their diet with fruits of the forest in autumn and winter, when where these offer them sufficient cover to find places for nesting and feeding there are few invertebrates available. on invertebrates. Because of their discreet behaviour they can usually only be located by their call. Notable species in the urban and peri-urban environments Distribution: they are considered sedentary nesters in Catalonia, although their population num- include the following: bers rise in the winter with the arrival of individuals from central and northern Europe in search of milder temperatures for spending the cold season. Male Eurasian blackcap SARDINIAN WARBLER (Sylvia melanocephala) Features: the species presents discreet colours, a long tail and, perhaps most distinctively, an outer bright-red ring around its eyes. Habitat: they can be found on cultivated land, brushwood scrub, hedges and pine groves, wherever there are well-devel- oped shrubs. Common in the city’s parks and gardens. Feeding: they eat invertebrates (cockroaches, worms, flies, butterflies and spiders) in the spring and summer and feed on fruits of the forest in the autumn and winter. Distribution: they are considered sedentary nesters in Catalonia, although their population num- bers rise in the winter with the arrival of individuals from central and northern Europe. 70 71 ROBINS AND BLACKBIRDS COMMON CHIFFCHAFF (Phylloscopus COLLYBITA) Some species of understorey birds also use the tree layer or ground as a supple- ment for feeding on worms, caterpillars, snails and spiders. Features: it is a small greenish-brown bird with a white breast. It bears a distinctive eyebrow-shaped white stripe above its eyes. It has a short tail and dark feet. Habitat: it prefers humid deciduous woods that have well-de- EUROPEAN ROBIN (Erithacus rubecula) veloped shrubs for nesting in. It is therefore found in Catalonia as a nester in the country’s humid areas. In the winter, how- Features: it is a small, round bird that is notable for its orange ever, a large number of individuals come over from central or face and breast. It is easily spotted, given its confident behav- northern Europe, who are less demanding when it comes to iour around humans, which corresponds to the territorial na- habitat and are, therefore, easily spotted in the city’s parks and gardens. ture that the species presents throughout the year. During the winter, males and females defend their feeding grounds with Feeding: insects and spiders that it finds among the leaves and branches of trees and shrubs. calls to mark out their territory. By contrast, during the spring, it is mainly the males that call out, to attract females and de- Distribution: it is a sedentary nester in Catalonia (in humid areas). ter other males from occupying their territory, a message they reinforce by displaying their orange breasts. The intensity of the orange corresponds to the individual’s dominance. Habitat: it lives in humid woods and can also be seen in the city’s allotments, parks and gardens, wherever there are humid spots with hedges and bare land for feeding. Nest: in holes in stones or tree hollows. EURASIAN WREN (Troglodytes troglodytes) Feeding: insects, earthworms, fruit and food leftovers. Features: it is a small brownish bird noted for its short tail, which it normally keeps raised. It is highly active and can be Distribution: it is sedentary and nests in Catalonia. Many robins come over from central and north- seen moving up and down the branches of shrubs, hiding be- ern Europe during the winter. tween their leaves, only to resurface again in search of small insects. Habitat: it lives in shrubby and woody areas and in gardens. It uses piled-up abandoned branches either for searching for food in or building its nests with. Photo: Wikimedia Nest: it lives in shrubs or holes in walls. The male builds sev- eral nests from moss, grass and leaves, one of which the female chooses and lines with feathers to begin the breeding process. Feeding: it eats insects, larvae, spiders and small seeds. Distribution: they are considered sedentary nesters in Catalonia, although their population num- bers rise in the winter with the arrival of individuals from central and northern Europe. 72 73 MAMMALS BLACKBIRD (Turdus merula) Features: males are black with a yellow beak and yellow circle around their eyes, whereas female are brownish (without any COMMON OR EUROPEAN HEDGEHOG (Erinaceus europaeus) yellow in their beak or around their eyes). Habitat: this is a nocturnal insectivorous mammal that lives Habitat: it lives in humid woods and is very frequently found in areas with a good herbaceous or shrubby cover, offering it in the city’s parks and gardens, where it can be easily spotted opportunities for moving about, feeding and nesting in. Humid walking and jumping abruptly in search of food. In fact, it is a forest borders with shrubby cover make ideal places for this highly ubiquitous species that also occupies cultivated land species. In this regard,structural heterogeneity becomes a and open areas with scrubland, shrubs and trees. key element for its development, with hedges and herbaceous perennials near to woody areas being especially important. Nest: it builds it from soil and small branches on the branches of tall shrubs or small trees. Stone walls and water points are other determining factors It is shaped like a wide cup. for the establishment of this small mammal. Feeding: an omnivorous bird, it feeds on insects, snails, fruit, food leftovers etc. Even so, it shows a Photo: Sergi Garcia Feeding: mainly on small invertebrates, such as snails, worms, preference for earthworms, making it easy to spot on grass lawns, especially where they have been slugs and cockroaches, although it will not miss an opportuni- recently watered, when earthworms are forced to come up to the surface to breathe. ty to eat food leftovers, cat food and dog food. Distribution: it is sedentary and nests in Catalonia. Blackbird population numbers rise in the winter, Nest: it is spherical and made from grass, straw, hair and other elements it finds. It usually builds with the arrival of individuals from central and northern Europe. Blackbird population numbers rise its nest under tree trunks and stones or in dense bramble bushes. It uses accumulated branches in the winter, with the arrival of individuals from central and northern Europe. for nesting in. Location: note the presence of hedgehogs in the Parc de la Ciutadella, the Laberint d’Horta and the Palau de les Heures. Common or European hedgehog (Erinaceus europaeus). Photo: Hedgehog in defensive strategy. Photo: Sergi Garcia Sergi Garcia 74 75 ANNEXE 3 SHRUBBY PLANT OF USE TO FAUNA Scientific name Common name Sunshine Flowering Nectariferous Fruit Host plant Scientific name Common name Sunshine Flowering Nectariferous Fruit Host plant Anthyllis cytisoides N/A Sunshine Sp/Sm Yes No Phillyrea latifolia Mock privet Sunny/semi- shaded Sp No Yes Arbutus unedo Strawberry tree Sunny/semi- Two-tailed shaded A/W Yes Yes pasha Pistacia lentiscus Mastic tree Indifferent Sp Yes Yes Bupleurum fruticosum Shrubby hare’s ear Sunshine Sp/Sm Yes No Average Prunus spinosa Blackthorn Sunshine W/Sp Yes Yes Quercus coccinea Scarlet oak Sunshine Sp Pollen Yes Buxus sempervirens Boxwood Indifferent Sp Yes Yes High Cleopatra Calluna vulgaris Common heather Sunshine Sm/A Yes No Rhamnus alaternus False olive Indifferent Sp Pollen Yes Butterfly Common brimstone Cornus sanguinea Common do- gwood Semi-shaded Sp Yes Yes Rhamnus lycioides Black hawthorn Sunshine Sp No Yes Crataegus monogyna Common hawthorn Indifferent Sp Yes Yes Scarce swallowtail Rosa canina Dog-rose Sunny/semi- shaded Sp Yes Yes Erica arborea Tree heath Sunny/semi- Rosa sempervirens Evergreen rose Sunny/semi- W/Sp Yes No shaded Sp Yes Yes shaded Erica multiflora Heather Sunshine A/W Yes No Rubus idaeus Red raspberry Semi-shaded Sp/Sm Yes Yes Ilex aquifolium Common holly Indifferent Sp/Sm Yes Yes Rubus ulmifolius Elmleaf black- berry Sunshine Sp Yes Yes Yes Juniperus communis Common juniper Sunny/semi- shaded Sp No Yes Ruscus aculeatus Butcher’s- broom Semi-shaded Sp No Yes Juniperus oxycedrus Prickly juniper Sunshine W/Sp No Yes Sunny/semi- Juniperus phoenicea Phoenicean Sambucus nigra Elderberry shaded Sp Yes Yes juniper Sunshine W/Sp No Yes Sarothamnus Laurus nobilis Sweet bay Semi-shaded Sp Yes Yes scoparius Scotch broom Sunshine Sp Yes No Lonicera implexa Minorca honey- Sunny/semi- Spartium junceum Spanish broom Sunshine Sp Yes No Pea blue suckle shaded Sp Yes No Yes Ulex parviflorus Gorse Sunshine Sp Pollen No Yes Ligustrum vulgare Common privet Sunny/semi- shaded Sp/Sm Yes Yes Viburnum tinus Laurustinus Sunny/semi- shaded W/Sp Yes Yes Lycium europaeum Box-thorn Sunshine Sp/Sm Yes Yes Vitex agnus-castus Chaste tree Sunny/semi- Sp/Sm Yes No Myrtus communis Common myrtle Sunny/semi- shaded shaded Sp/Sm No Yes Ononis natrix Yellow rest- harrow Sunshine Sp/Sm Yes No Sp = spring, Sm = Summer, A = autumn, W = winter Phillyrea angustifolia False olive Sunny/semi- tree shaded Sp No Yes 76 77 SHRUBBY SCRUBS OF USE TO FAUNA Flowe- Nectarife- Scientific name Common name Sunshine Host plant ring rous Aster sedifolius Michaelmas daisy Sunshine A Yes Asparagus acutifolius Wild asparagus Sunshine E Yes Cistus albidus Grey-leaved cistus Sunshine Sp Pollen Green hairstreak Cistus monspeliensis Montpellier cistus Sunshine Sp Pollen Cistus salviifolius Sage-leaved rock- rose Sunshine Sp Pollen Green hairstreak Dorycnium pentaphyllum Prostrate Canary clover Sunshine Sp/Sm Yes Globularia alypum Globe daisy Sunshine Sp Yes Scarce swallowtail Helichrysum italicum Curry plant Sunshine E Yes Helichrysum stoechas Curry plant Sunshine E Yes Hyssopus officinalis Hyssop Sunshine Sm/A Yes Lavandula angustifolia Common lavender Sunshine E Yes Lavandula stoechas Spanish lavender Sunshine Sp Yes Lithospermum fruticosum Shrubby gromwell Sunshine Sp Yes Aromatic plants in Park Güell Marrubium vulgare Japanese mock orange Sunshine Sp/A Yes Melissa officinalis Lemon balm Sunshine/ shade Sp/Sm Yes Origanum vulgare Orenga Sunshine Sp/Sm Yes Phlomis herba venti Rough-leaved Jeru- salem sage Sunshine Sp/Sm Yes Rosmarinus officinalis Rosemary Sunshine Sp/S/A Yes Lang’s short-tailed blue Ruta chalapensis Fringed rue Sunshine Sp/Sm Yes Southern scarce swallowtail Salvia officinalis Sage Sunshine Sp Yes Santolina chamaecyparissus Cotton lavender Sunshine Sp/Sm Yes Satureja calamintha Lesser Calamint Sunshine Sm/A Yes Satureja montana Winter savory Sunshine E Yes Thymus vulgaris Common thyme Sunshine W/Sp Yes Panoptes blue Thymelaea tinctoria Sparrowwort Sunshine W/Sp Yes Sp = spring, Sm = Summer, A = autumn, W = winter Cotton lavender (Santolina chamaecyparissus) 78 79 ANNEXE 4 SHRUB FRUITING CALENDAR CLIMBER-PLANT AND HEDGEROW FRUITING CALENDAR Scientific Common Ja- Fe- Septem- Novem- Decem- March April May June July August October name name nuary bruary ber ber ber Arbutus Strawberry Scientific Common Ja- Fe- Septem- Novem- Decem- March April May June July August October unedo* tree name name nuary bruary ber ber ber Buxus Asparagus Wild sempervirens Boxwood acutifolius asparagus Cornus Common Clematis Old man’s sanguinea dogwood vitalba beard Crataegus Common Hedera helix Common ivy monogyna* hawthorn Lonicera Minorca Ilex Common implexa honeysuckle aquifolium holly Rosa canina Dog-rose Juniperus Common communis juniper Rosa Evergreen sempervirens rose Juniperus Prickly oxycedrus juniper Rubia peregrina Wild madder Juniperus Phoenicean phoenicea juniper Rubus Elmleaf ulmifolius blackberry Laurus nobilis Sweet bay Smilax aspera Rough bindweed Lycium europaeum Box-thorn Vitis vinifera Common grape vine Myrtus Common communis myrtle Phillyrea False olive angustifolia tree Phillyrea latifolia Mock privet Pistacia lentiscus Mastic tree Prunus spinosa Blackthorn Quercus coccinea Scarlet oak Rhamnus alaternus* False olive Rhamnus Black lycioides hawthorn Ruscus Butcher’s- aculeatus broom Sambucus nigra Elderberry Viburnum tinus Laurustinus *Butterfly host plant. Approximate fruiting ranges. 80 81 INDEX INTRODUCTION 84 CONSERVATION INITIATIVES Conserving grasslands in unused land 86 Conserving barren vegetation 90 The area running from the border of the field to the shrubs has to be mowed 92 IMPROVEMENT INITIATIVES D efining types of grasses, fields and grasslands associated with a specific form of maintenance 94 Adapting the maintenance of lawns 98 S electing spaces capable of conversion to fields or grasslands 100 Naturalising lawns and banks 102 Applying differentiated mowing 106 Planting groups of shrubs or fruit trees on lawns and fields 108 Planting flower beds with alternative species to grass 109 Sowing grasslands 110 Complementary initiatives on lawns and fields 112 Promoting new criteria 113 ANNEXE 1 Ruderal vegetation of use to fauna 114 ANNEXE 2 Bees and solitary wasps 120 ANNEXE 3 Beekeeping flora 126 ANNEXE 4 Mediterranean dry grasslands 130 83 GRASSES, FIELDS AND GRASSLANDS INTRODUCTION “Lawns” refer to dense and uniform covers made up of a series of species of Changes in paradigm have to be made through an ongoing dialogue where expla- grasses or legumes or a mixture of both, that people tend to mow from time to nations can be given to city residents on the goals behind each initiative. Natu- time. Made up of several herbaceous species, fields are less intensely main- ralisation practices are sometimes confused with carelessness or lack of main- tained and are associated with less frequent mowing and clearing than lawns. tenance, leading to rejection or scepticism at the least. That is why new criteria When tall and leafy herbaceous species appear in a field, it is referred to as a have to be linked to the goal of improving urban green space and biodiversity and, grassland, which is associated with very low maintenance. Therefore, depending by extension, quality of life and a commitment to sustainability. on the maintenance they receive, lawns can evolve into fields and grasslands. Open spaces such as fields and grasslands are extremely valuable for biodiversi- ty, as they are a habitat with a large quantity of invertebrates at the bottom of the food chain for many groups of fauna. Their presence is diminishing in both cities and natural environments. Barcelona is not noted for having large extensions of grass, though some histor- ical parks (Ciutadella, Montjuïc, Palau de Pedralbes) do have a notable presence of grass. Over the last few decades, with the creation of new parks and gardens throughout the city’s districts, there has been an increase in the surface area allocated to grass. The Estació del Nord and Parc de la Trinitat are examples of parks with generous spaces of grass. As for grasslands, these can be found in peri-urban spaces and on plots of land inside the city centre waiting to be put to new use (building or gardening). Grass provides space that is appreciated by city residents whether for playing games, holding gatherings or celebrations or for resting in. A more sustainable management A more sustainable urban management implies changes involving rationalised use of resources. As grass maintenance creates considerable demands on water and resources (staff, maintenance, etc.,), it would useful to develop new criteria more in line with sustainability. A definition is therefore needed for a graded se- ries of types of green (lawns, fields and grasslands) according to their mainte- nance. Current herbaceous species, the locations of these spaces and the uses that city residents put to them will determine the maintenance associated with each type of green. This will mean making regular maintenance in the city’s parks and gardens compatible with naturalisation in selected sites and involve leaving lawns to develop. Such maintenance will require reduced intervention when it comes to mowing, irrigating and clearing, thereby creating a new model of treat- ment - without lowering the aesthetic and functional quality of these places - that is also intended to ensure a more sustainable management of resources and an increase in biodiversity. Naturalising leads to an increased number of herbaceous species to the benefit of fauna. Such initiatives are being tried out in parks with large extensions of grass, such as Parc de la Trinitat. Work is currently going ahead to enable such practices to be exported to other parks, with the idea of adapting them to specif- ic biodiversity and resource-saving needs. Vviper’s bugloss (Echium vulgare) grassland on Montjuïc. 84 85 CONSERVATION INITIATIVES Conserving grasslands on unused land > A large number of invertebrates are estab- lishing themselves there, so enriching the ar- to preserve biodiversity ea’s biodiversity while also providing a food re- source for amphibians, reptiles, insectivorous birds and some mammals. Grasslands also of- fer protection to the larvae and eggs of many invertebrates spending the winter sheltered in these spaces. Once again, all this biodiversity will benefit the landscape’s natural balance and quality. > These spaces produce large quantities of seeds during the winter which will be used as food for goldfinches (Carduelis carduelis), greenfinches (Carduelis chloris), serins (Seri- nus serinus) and house sparrows (Passer do- mesticus), among other species, during a time of the year when food resources are scarce. Grasslands are also important in the spring, Unused land given that the above-mentioned granivorous in Carrer de la species of birds will feed their offspring with Mare de Déu del Coll small insects during the breeding season. (See annexe 1: Ruderal vegetation of use to fauna.) Italian striped-bug (Graphosoma lineatum) on a wild carrot (Daucus carota) Description/application Grasslands are found not just in peri-urban areas but also in the city, where they establish themselves on unused land. Such grasslands are made up of a whole series of herbaceous annual plants, such as false yellowheads, thistles, fennel, brèdes and grasses, all adapt- ed to living in altered environments and natu- ral colonisers of these open spaces. These grasslands play a vitally important eco- Uromenus rugosicollis logical role: Southern green shield bug (Nezara viridula) Fruiting false yellowhead (Dittrichia viscosa) Flowering false yellowhead (Dittrichia viscosa) 86 87 > The spring flowering of these grasslands helps to attract a large quantity of > These make up the habitat of very beneficial fauna that play a part in the pollinating insects. (See annexe 2: Bees and solitary wasps and see annexe 3: biological control of pests and diseases in parks and gardens. Such is the case Beekeeping flora). with hoverflies (wasp-shaped flies). They are identifiable by their stationary fly- ing. Their larvae feed on aphids. Such species therefore need to be conserved, so it is important to prevent the accumulation of rubbish (often associated with the presence of rats) which gives it a degraded, marginal appearance that fails to do justice to its ecological impor- tance. Conservation work on grasslands can be accompanied with appropriate signage to promote the natural value of these herbaceous communities. Large white butterfly (Pieris brassicae) sipping from a Bermuda White rocket (Diplotaxis erucoides) buttercup (Oxalis pes-caprae) Cleopatra butterfly (Gonepteryx cleopatra) sipping from viper’s Common poppies (Papaver rhoeas) and sage (Salvia officinalis) Hoverfly family bugloss (Echium vulgare) 88 89 CONSERVATION INITIATIVES Conserving barren vegetation to preserve biodiversity Black redstart (Phoenicurus ochruros) Barren vegetation along Carrer de la Farigola Description/application Barren vegetation, defined as large spaces It is advisable to conserve barren land and pre- with little herbaceous cover, are becoming vent it from being used as a space for rubble sites of great natural value, seeing as they pro- and rubbish dumps given its important natural vide a habitat for many species of birds that value. Signage can be worked on to inform city feed off the ground. Such is the case of wood residents of the importance of these spaces. pigeons (Columba palumbus), whose diet not only consists of tree leaves but also a large va- riety of seeds and fruit they find on the ground. Black redstarts (Phoenicurus ochruros), white wagtails (Motacilla alba) and, above all, in the winter,species of birds from the finch family such as common chaffinches (Fringilla coe- lebs) use such barren land, with little herba- ceous cover, for feeding on seeds. White wagtail (Motacilla alba). Photo: Xavier Ferrer 90 91 CONSERVATION INITIATIVES The area running from the border of the field to the In the specific case seen in the photo below, it is preferable to start clearing from shrubs has to be mowed to preserve its fauna the bottom to the top and not to create islands of grass that are difficult for fauna to escape from. Description/application When a field or grassland has to be mowed or cleared, it will be done in such a way that the fauna there are provided with the means for escaping to shelter areas, such as groups of shrubs, flower beds or rocks. This means starting the mowing from the area with the most visitors and directing the mowing or clearing towards shelter areas. Such initiatives can be considered where clearings have to be made to allow for fire-protection buffer strips. Jardí de Petra Kelly. Montjuïc Jardins de Joan Brossa Parc de la Trinitat 92 93 IMPROVEMENT INITIATIVES Defining types of lawns, fields and grasslands So then, the following types are proposed for the purposes of this document: associated with a specific form of maintenance to Temperate-climate lawns (C3): present considerable maintenance costs and boost biodiversity high requirements for water resources. They are made up of mixtures of seeds from three or four rural grass species that offer vigour throughout the year and resistance to trampling, dryness and occasional puddles. Combinations of Fes- tuca arundinacea, Lolium perenne and Poa pratensis are common in public parks, with Cynodon dactylon added to areas with milder temperatures and Festuca ru- bra to lawns with greater shade. Their optimal development is at temperatures between 12°C and 24°C. They need intense maintenance that varies according to the species that make up the lawn, the use that the public make of them and their location, among other factors. Hot-climate lawns (C4): are better at resisting dryness and high temperatures than temperate-climate lawns and are therefore associated with fewer water requirements and less maintenance work. Besides having their optimal devel- opment at high temperatures (25°C-35°C), they tolerate mowing completely and require less manure and fertiliser than C3 temperate-climate lawns. During the winter they enter a period of dormancy and turn yellowish. Zoysia sp., Paspalum sp. or Cynodon sp. are just a few of the species that usually make up hot-climate lawns. Parc de la Trinitat Ornamental and natural fields and grasslands: are established through the de- velopment of temperate- or hot-climate lawns and are then managed under a less intense maintenance programme, as defined in the following table: Description/application > A programme has to be established for de- Recommended mowing Frequency of mowing Frequency of watering fining several types of lawn so that each one height (mm) is associated with a specific level of mainte- 1 weekly watering/spring-autumn Ornamental fields 80 (after flowering) 6-7/ year nance. Parameters such as mowing frequency 2 weekly watering/summer and height will enable us to have everything Natural fields 120 1-3/ year 1 weekly watering/summer from lawns that are conventionally main- Grasslands 120 1 biennial No tained (located in iconic or historical places or needed as leisure spaces by public demand) to fields and grasslands that have fewer main- Carrer de Montevideo. Grassland tenance requirements. Guidance maintenance parameters taken from the Technical Gardening Regula- tions NTJ 14 G Maintaining Non-Sport Lawns and Fields > Barcelona currently has several types of lawn. Temperate-climate lawns (C3) and hot-climate lawns (C4) on the one hand, and fields on the other. The aim behind this docu- ment is to take an in-depth look at the concept of fields and establish several categories of them, based on management criteria, mainly mowing frequency and height and irrigation. Field on Plaça de les Glòries Catalanes 94 95 Special case of wild boars There has to be a reduction in food availability (Sus scrofa) • No cat-feeding points must be allowed in ar- eas near to Parc de Collserola > The last few years have seen wild boars • Feeding boxes have to be redesigned to stop making more and more frequent inroads into wild boars from accessing cat food. urban areas. This has affected many green • L aunching awareness-raising campaigns to spaces, in particular grass parterres with au- call on residents not to feed wild boars. tomated irrigation, whose grass carpets wild • Rubbish containers need to be strengthened boars find suitably humid to raise and rum- with anti-tipping systems. mage in search of roots, bulbs and inverte- • Secure and closed design of bins in the brates such as earthworms. Wild boar (Sus scrofa) and wild boar piglets. Photo: Sergi García peri-urban area to prevent tipping and ac- Cat-feeding points have to be Bins with lids to prevent wild Night-stalking and battues to control the cess to the food leftovers they may contain. kept further away and work boars from accessing food done on their design leftovers population of wild boars in Parc de Collserola (currently estimated at around 1000) and cap- Access to the city must be made more diffi- turing problematic wild boars in urban areas cult for wild boars are becoming crucial to resolving the problem. • Clearing shrubby covers in areas of conflict, As for the latter point, note that wild boars either by mechanical means or putting sheep can travel large distances in just a few days or goats out to pasture there. (dozens of kilometres) and that once they are • Strengthening perimeter fences, if possible used to feeding on the large range of food on with a concrete base, to prevent wild boars offer in the city (cat food, bins, rubbish con- from accessing the parks affected. Understoreys have tainers etc.,) it is hard for them to change their • Using electric fences to strengthen perime- to be removed in behaviour. This means they continually return areas of conflict Effects of wild-boar rummaging in the Parc del Laberint’s ter fences. and make incursions into urban areas despite domestic garden. • Installing cattle grids. relocating back to the natural environment; among other reasons, because they learn from Change in type of vegetation their mother, while they are still very young, to • Change in the management of the grass par- feed that way and consequently pose a risk terres near the Barcelona-facing slope in to city residents. Even so, the problem of wild Parc de Collserola. The proposal is for these Fence around the boars is becoming so complicated that the in- Parc del Laberint spaces to be gradually replaced by dry fields, d’Horta’s domestic itiatives described above have to be accompa- garden which are no doubt less attractive to this nied by others that will make it hard for wild mammal. (See annexe 4: Mediterranean dry boars to enter the city: grasslands). Parc del Laberint d’Horta’s perimeter fence Cattle grid. Parc Effects of wild-boar rummaging in Creu de Pedralbes de les Heures 96 97 IMPROVEMENT INITIATIVES Adapting the maintenance of lawns to boost biodiversity Wood pigeon (Columba palumbus). The Palau de Pedralbes Gardens Description/application Lawns are seen as leisure spaces and therefore subject to strong citizen pres- sure and require a considerable effort to maintain them. Such intense mainte- nance makes lawns of little use to fauna, although it should be pointed out that generalist species of birds such as wood pigeons (Columba palumbus), black- birds (Turdus merula) and white wagtails (Motacilla alba) usually search for food on lawns. > Despite the dry periods both temperate- and hot-climate laws are subject to, where the associated maintenance levels so permit and useful flowering plant species are observed, a delay in the first mowing, to respect such flowering and allow insects access to nectar and pollen as soon as possible, constitutes a good management measure to the benefit of biodiversity. Jardins de Mossèn Cinto Verdaguer 98 99 IMPROVEMENT INITIATIVES Selecting spaces capable of conversion to fields or grasslands to increase their natural usefulness Montjuïc grassland Description/application > Suitable spaces have to be selected for such differential treatment, for conversion into fields or grasslands. So, by following gen- eral criteria for location, area, public use of the space, sunshine exposure, proximity to water points, maintenance and fire risks, spaces will be selected where naturalisation programmes can be carried out, whether in urban parks, large and small gardens, slopes, natural spac- es or even roads and traffic junctions. Natural field along Carrer dels Jocs del 92 Natural field in Parc de Diagonal Mar 100 101 IMPROVEMENT INITIATIVES Naturalising lawns and banks to promote biodiversity > Less mowing: once the spaces have been selected, the management work must focus on mowing. The type of maintenance that each space receives will depend on the decision to turn it into an ornamental field, a natural field or a grassland. Ornamental fields: maintenance will involve between six and seven mowings a year. Note that the location of the field, the herbaceous species of which it is formed, the resources available and other factors such as rain and humidity will end up determining the mowing calendar. As a guideline: Ja- Fe- nuary bruary March April May June July August Septem- ber October November December Mowing clippings need to be incorporated into the surface of the fields, except where they may pose a fire risk. Natural fields: maintenance will involve between one and three mowings a year. This less intensive mowing will need to respect spring flowering and autumn seeding (October), whereby a correct maintenance programme will have to con- sist of a single mowing at the start of March and no subsequent mowing until the autumn-winter. Many natural fields require mowing during the April-May period. Note that these spring mowings provide fields with flowers during the summer. As a guideline: Ja- Fe- Septem- nuary bruary March April May June July August ber October November December Jardins de Joan Brossa = optional Description/application Mowing clippings need to be incorporated into the surface of the fields, except where they may pose a fire risk. > Lawns and banks that are of little interest to fauna must be left to develop into fields or Grasslands: maintenance involves a bienni- grasslands and become a habitat that favours al mowing to maintain the field’s herbaceous biodiversity. There is no need for keeping the state. Tall-grass and wild-flower areas will cre- herbaceous species homogeneous. Where the ate a feeding and breeding habitat for butter- space is left to develop into a field or grass- flies and other invertebrates, so constituting land, it will be colonised by several herba- the bottom of the food chain that other groups ceous species over time, each of which will of fauna will feed from. flower and have associated fauna and there- fore continue increasing the ecological value of the space. These spaces become essential in the spring and summer, when they host a Feixes de Collserola’s grassland community of invertebrates of crucial impor- tance for several groups of fauna, and at the start of winter, with the seeding of herbaceous species that feed numerous granivorous birds. 102 103 > Increased mowing heights: high mowing > Reduced frequency of watering: fields and grasslands in general must not heights allow the flowering to be respected have too much water an the management should focus on mowing. This will of species such as white clover (Trifolium re- therefore enable us to save on water consumption. pens) and common daisies (Bellis perennis), Recommended mowing both low-growing plants and very useful for heights (mm) Ornamental fields: these will be watered according to their needs and the time their flowers, which are rich in nectar and pol- Ornamental fields 80 of year. The appropriate amounts of watering determined will be supplied. As a len. High mowing heights also enable fields to guideline: a weekly watering in the spring and autumn and two waterings a week Natural fields 120 retain a certain degree of humidity, thereby in the summer. Spaces close to sprinklers and other irrigation elements must be benefiting invertebrate while reducing the fre- Grasslands 120 cleared from time to time so water can be sprayed without any obstacle in the quency of watering. way. Natural fields: these will be watered once a week during the summer period. Grasslands: these will not be watered. Dark clouded yellow (Colias crocea) sipping from a clover (Trifolium sp.) Common daisies (Bellis perennis) Parc de la Trinitat 104 105 IMPROVEMENT INITIATIVES Applying differentiated mowing to improve the > Geometric elements or winding strips of vegetation will have to be incorporated for landscape and biodiversity, according to use landscape purposes. > Geometric figures will have to be created around tree trunks to prevent weeding-ma- chines blades from cutting into tree bark and reduce maintenance work. > Such differentiated mowing can involve a redistribution of certain areas’ public uses. For example, people will not be able to picnic or read on areas where the grass is higher. It is advisable to use signage for directing the pub- lic on how they should use these spaces. Yoga enthusiasts. Parc de la Ciutadella. Grassland on Sot del Migdia. Montjuïc Description/application Theuniformity of the space has to be broken > Creating herbaceous layers at several up by providing it with several herbaceous lay- heights depending on how close they are to ers, based on aesthetic and functional criteria. more visited areas and thereby establishing a lesser to greater height gradient the further > Mowed or cleared pathways need to be we get from transit areas (paths, roads, facil- created inside fields or grasslands for people ities etc.) For example, beside a path or high- to walk along and prevent trampling on natu- ly visited area, the first two or three metres ralised areas while encouraging the public to can be cut at 10 cm. From then on, the further observe the biodiversity associated with these away we are from the transit area, new herba- spaces. Depending on their width, such areas ceous buffer strips can be created by steadily can also act as fire-protection buffer strips. increasing their heights. Parc de la Trinitat Meadow on Turó Park used as an area for dogs Parc de la Trinitat Jardins de Joan Brossa Parc de la Trinitat Picnic. Passeig de Sant Joan 106 107 IMPROVEMENT INITIATIVES IMPROVEMENT INITIATIVES Planting groups of shrubs or fruit trees on lawns Planting flower beds with alternative species to and fields to promote biodiversity grass to promote biodiversity Jardins de William Shakespeare Ivy (Hedera helix) parterres. Parc del Laberint d’Horta Description/application Description/application > Lawns and fields need to be made more > Creepers requiring less expenditure on structurally complex through the presence of water may be considered as an alternative to shrub borders (mastic trees, chaste trees, rose grass. Creepers generally tolerate moderate bushes, bramble bushes, etc.), or fruit-bearing trampling, are aesthetically pleasing and, in trees such as cherry trees, plum trees, apple some cases, present flowers that are attrac- trees which can be used as feeding, sheltering tive to bees and other pollinating animals. and breeding places for wild fauna. Very attractive combinations can be made. Example: Lippia nodiflora and Achillea crith- mifolia. The former produces a summer carpet of small green leaves and abundant and very Carrer de Mandri at its junction with Ronda del General melliferous white and pink flowers, while the Mitre Olive trees (Olea europaea). Parc de la Trinitat latter develops vigorously during the winter. Another option, already present in the city, is to plant ivy in parterres, and yet another, to plant species such as bigleaf periwinkle (Vin- ca major) and asparagus fern (Asparagus den- siflorus). 108 109 IMPROVEMENT INITIATIVES Sowing grasslands to promote biodiversity > If butterflies are wanted in these grass- lands then: • Suitable host plants will have to be grown for each species of butterfly. So, for exam- ple, red admirals (Vanessa atalanta) use eastern pellitory-of-the-wall (Parietaria officinalis) and stinging nettle (Urtica sp.) as host plants while the common blue (Pol- yommatus icarus) uses alfalfa (Medica- go sativa) and common bird’s-foot trefoil (Lotus corniculatus) among other plants. Cleopatra butterfly (Gonepteryx cleopatra) Note that many species of butterflies pres- ent a considerable degree of specificity as they use a specific species or species from the same botanical family as host plants. It is advisable to plant native species and complement host plants with flora that are rich in nectar, such as knapweed, pincushion Roof of the Biblioteca Zona Nord, in Nou Barris flowers and viper’s bugloss. Description/application • Sowing plants with nectar-secreting flowers Common blue (Polyommatus icarus) for adults to feed on. Many flowers in the city > When we consider creating grasslands > It would be useful to sow alfalfa fields that are used for attracting adults are alien by direct sowing, we will need to take care in where the public are expected to use it for species, which offer nectar with features choosing plants that are useful for the fau- various one-off activities, given that the plant similar to that of native plants. So, while the na. Some species of birds show a preference offers a useful nectar-secreting content for butterflies are clearly dependent on lay- for certain grasses. So, for example, finches pollinating fauna, on the one hand, and, on the ing eggs on native plants, when it comes to and sparrows like false yellowheads, brèdes, other, thanks to its large capacity to re-shoot, adult feeding, there are no significant ge- thistles and Brassicaceae in general, such as tolerates two and even three annual clearings, neric differences in nectar-secreting con- white rocket. making it easier to maintain these spaces. tent between the native and alien species. Viper’s bugloss (Echium vulgare) Grassland made up of fennel, common thatching grass and other grasses Parc de Montjuïc Grassland made up of fennel, common thatching grass Alfalfa (Medicago sativa) fields. Plaça de les Glòries and other grasses. Parc de Montjuïc knapweed (Centaurea sp.) 110 111 IMPROVEMENT INITIATIVES IMPROVEMENT INITIATIVES Complementary initiatives on lawns and fields Promoting new criteria to gain public involvement and to promote biodiversity support for new initiatives Description/application > A good idea is to use informative materi- Wooden pyramid at Mas Ravetllat al to link naturalised grass areas and differ- Description/application entiated treatment to increased biodiversity and rationalised urban management. And link > these aspects to improved quality of life. Installing insect hotels and spirals to pro- mote pollinating fauna. > Installing wooden pyramids to promote wood-eating insects. > Given the scarcity of mud in urban con- texts, certain lawn and field areas could be used for creating bogs for swallows and ena- bling them to gather material for building their nests. Whether or not there are nearby water points will determine the feasibility of such Bosc de Turull insect spiral initiatives. 112 113 ANNEXE 1 RUDERAL VEGETATION OF USE TO FAUNA A few examples of ruderal plants of use for feeding pollinating insects: Ruderal vegetation is made up of a series of herbaceous species that opportun- Scientific name Common name istically appear in soils which have been damaged as a result of land movements, Alyssum maritimum Sweet alyssum fires, abandoned land etc. In ecological terms, these herbaceous species pres- ent an opportunistic reproductive strategy known as “r-strategy”. Thanks to their Artemisia vulgaris Mugwort high production of seeds during their annual cycle, these plants have a high re- Borago officinalis Borage productive potential which enables them to be the first to colonise spaces that Brachypodium phoenicoides Thinleaf false brome have undergone some sort of alteration. They are therefore species typical of the Calendula arvensis Field marigold first stages of colonisation. Centaurea sp. Centaury Centaurea aspera Rough star-thistle Specialist or K-strategy individuals, however, have less reproductive potential but reproduce during their long biological cycle. These are more complex species Centaurea paniculata Jersey knapweed that are better at competing for resources and which consequently end up sup- Cirsium vulgare Spear thistle planting the opportunistic species in stable environments. Convolvulus arvensis Field bindweed Daucus carota Wild carrot In any case, this type of ruderal vegetation is of vital importance for fauna, seeing Diplotaxis erucoides White rocket as many insects and birds too feed on them directly. So, for example, adult paint- Echium vulgare Viper’s bugloss ed ladies (Vanessa cardui) not only feed on the nectar of thistle flowers but also Epilobium hirsutum Great willowherb use nettle, mallow and viper’s bugloss, among other species, as their host plant. European serins (Serinus serinus) and European greenfinches (Carduelis chlo- Eryngium campestre Field eryngo ris) show a great predilection for the seeds of white rocket (Diplotaxis erucoides) Foeniculum vulgare Fennel and watercress-leaved rocket (Erucastrum nasturtiifolium) while European gold- Galactites tomentosa Purple milk thistle finches (Carduelis carduelis) have a beak that is specially adapted for gathering Galium aparine Cleavers thistle seeds. These are just a few of the many examples that demonstrate how Galium lucidum Goose grass ruderal plants play a crucial role in biodiversity. Lotus corniculatus Common bird’s-foot trefoil Malva sylvestris Common mallow Melilotus sp. Melilot Mercurialis annua Annual mercury Psoralea bituminosa Pitch trefoil Reichardia picroides Brighteyes Scabiosa atropurpurea Mourningbride Senecio vulgaris Groundsel Sinapsis alba White mustard Silybum marianum Milk thistle Sonchus oleraceus Common sowthistle Sonchus tenerrimus Slender sowthistle Taraxacum officinale Common dandelion Urospermum dalechampii Smooth Golden Fleece Urtica dioica Common nettle Painted lady (Vanessa cardui) on bougainvillea 114 115 A few examples of ruderal plants of use to granivorous birds: Common name Scientific name Bird Lamb’s quarters Chenopodium album, Chenopodium murale, European serins and Amaranthus retroflexus, Amaranthus albus, Southern green shield bugs etc. Thistles Sylibum sp., Centaurea sp., Cardus sp., European goldfinch Cirsium sp., Onopordum sp. White rocket Diplotaxis erucoides European serins and Southern green shield bugs Watercress-leaved Erucastrum nasturtiifolium European serins and rocket Southern green shield bugs False yellowhead Dittrichia viscosa European goldfinch Common thatching grass (Hyparrhenia hirta) Fennel (Foeniculum vulgare) Common nettle (Urtica dioica) Pitch trefoil (Psoralea bituminosa) Wild carrot (Daucus carota) with longhorn beetles (Chlorophorus varius), a regular visitor of umbelliferae family plants and composts Rough star-thistle (Centaurea aspera) Annual mercury (Mercurialis annua) 116 117 Field marigold (Calendula arvensis) Common mallow (Malva sylvestris) Red-root amaranth (Amaranthus retroflexus) Sweet alyssum (Alyssum maritimum) Purple milk thistle (Galactites tomentosa) Borage (Borago officinalis) Watercress-leaved rocket (Erucastrum nasturtiifolium) Field eryngo (Eryngium campestre) Field bindweed (Convolvulus arvensis) Sowthistle (Sonchus sp.) 118 119 ANNEXE 2 BEES AND SOLITARY WASPS BUFF-TAILED BUMBLEBEE (Bombus terrestris) Habitats: once the winter cold has passed, queen bees search Pollinating insect populations are dropping Many of these species of bees and solitary for abandoned underground dens or tree hollows or holes in number worldwide, with serious repercus- wasps have been declining in numbers due to in walls for nesting. Queen bees are not the only females to sions on the functioning of our ecosystems. In the use of agricultural pesticides, loss of qual- survive in the winter. The nest here is where they build a ball, fact, it is estimated that 80% of wild flowers ity herbaceous habitats and fragmentation of made of grass, pollen and nectar, which they then use for lay- and 70% of cultivated plants depend directly habitats. It has only been the over last few ing their eggs in. They also build a container from wax where on the pollinating activities of such insects, years that they started to receive recognition they keep the nectar and pollen for feeding their larvae off- mainly bees and wasps, but also cockroaches, for their ecological value. spring. It is from this first batch of fertilised eggs that the first butterflies and other species. infertile (female) drones emerge, in search of food to feed the There are some thousand species of bees and new larvae with. Towards the end of the summer, after their When we refer to bees, the truth is we imme- over 700 species of solitary wasps in Spain. colonies have made considerable development, the queen diately think of western honey bees (Apis mel- Each of these species has its own specific bees lay unfertilised eggs, which turn into males, as well as lifera), the best-known of all bees or perhaps features and therefore feeds from different fertilised eggs, which become new queen bees. Males are not also bumblebees (Bombus sp.); in any case, flowers and uses specific nesting substrates. part of the colony and live solely to fertilise new queen bees. however, they are not the only representatives So, most of these species nest directly on the These bumblebees all die during the cold season, except for of the hymenoptera order to pollinate, as there ground, whether on bare soil or with a cer- new queen bees, which, by now fertilised, go out in search of a are many other known species of hymenoptera tain amount of herbaceous cover, depending new den for spending the winter and creating a new colony for described as bees and solitary wasps. While on the species, although there are also other when the good weather returns. these species do not live in colony-forming species that use dry materials, such as herba- hives or with the social organisation of honey ceous plant stems or trunks, for nesting in. Ecology: they pollinate between 25 and 30 flowers a minute and remain active above 5º C. They are bees and bumble bees, it should be noted that therefore great pollinators and very useful in agriculture. they play an equally important role in pollinat- Bees and solitary wasps devote a considera- ing flowers. ble part of their lives to finding a good place for nesting and laying their eggs in. Bees and wasps do not stay on in their respective hives and nests but lay their eggs in them and pro- vide food there so their larvae can develop properly. Females die before the next genera- CARPENTER BEES tion hatch and males, which live solely to re- produce, have an even shorter lifespan. Bees Habitats: they are noted as the only bees that are able to bore supply their hives with plant-based food (pol- hives in soft wooden branches and trunks, thanks to their len and nectar) and, therefore, pollinate many powerful mandibles. They create long tunnels where they plants in the process, whereas wasps provide lay their eggs along with a mixture of pollen and nectar for their nests with animal-based food (insects feeding their larvae on. They also re-use hives. An example of and spiders), thereby controlling populations carpenter bees are violet carpenter bees (Xylocopa violacea), of pest insects while helping to maintain the which can be easily identified by the metallic-blue colour of equilibrium in ecosystems. their wings and the characteristic sound of their flying. Violet carpenter bee (Xylocopa violacea) Species of bees in our environment include: Western honey (Apis mellifera) on a Chinese wisteria (Wisteria sinensis) 120 121 LEAFCUTTER BEES WASPS Habitats: nesting substrates vary considerably depend- Habitats: the European paper wasp (Polistes dominula) ing on the species, although there is a preference for and the European or German wasp (Vespula germanica) soft wooden cavities, which these bees fill with pieces of are two of the species found in the city. The two species leaves they themselves cut out, while reducing the sur- can be distinguished through their respective morpholog- face area of leaves. Their leaf-cutting does not general- ical features and habits. So, European or German wasps ly pose any serious problems for the plant. Dense plant have black antennae, yellow legs and a yellow and black stems and soil are also used as nesting substrates. Curi- pattern on their abdomen consisting of a black triangle Leafcutter bee (Megachile sp.). ously enough, unlike honey bees and bumble bees, which and two black dots across each segment. European paper Photo: Wikimedia transport pollen in “baskets” on their hind legs, leafcutter wasps, however, have orangey antennae and legs and a bees transport pollen on the ventral part of their abdomen different abdominal pattern; when they fly, their hind legs using its specialised hairs. Considered one of the most ef- can be seen trailing underneath. ficient groups in pollinating, this family is made up of nu- Paper wasps create rather small colonies. Their nests are merous species, most of which feed on pollen and nectar. made from a mixture of vegetable fibres and saliva and The family’s main genera include: Osmia, Megachile and European paper wasp (Polistes dominula) are joined up by a peduncle to walls, shrubs, roofs and Anthidium. other sheltered places that offer some protection. They mainly feed on insects and spiders and, to a lesser extent, on nectar and sugary substances they often ex- Detail of cut strawberry tree leaves (Arbutus tract from mature fruit. unedo) European or German wasps build large nests that are nor- mally located on the ground, either entirely or partially buried. They also take advantage of abandoned dens. They feed on insects and spiders, nectar and sugary substanc- es. They behave more aggressively than paper wasps. Note, however, that there is a large diversity of wasp fam- European or German wasp (Vespa germanica) CUCKOO BEES ilies in the hymenoptera order, some of which are preda- tors and therefore consumers of insects and spiders while Habitats: so called because they enter the nests of pol- others are endoparasites, such as ichneumonidae, whose len- and nectar-collecting species and lay their eggs in females use their long stinger to lay their eggs inside the their honeycombs. When cuckoo bee larvae hatch from animals they parasitise (spiders and caterpillars). In sum, their eggs, they feed on the nest’s stored pollen and on the they are a very useful group in the fight against pests in host species’ larvae. They nest on the ground. Some of the our green spaces. main genera are Halictus, Lasioglossum and Sphecodes. Cuckoo bee (Halictus sp.) Nest of European paper wasp (Polistes dominula) Nest of European wasp. Photo: Wikimedia 122 123 MEASURES FOR BOOSTING BEES AND SOLITARY WASPS: • Conserving grasslands. In the winter too, so they can be used as shelters for bees and wasps • L eaving the dry stems of herbaceous plants once they have flowered so they can be used as a breeding substrate • C onserving areas without herbaceous cover (bare soil) • Not using phytosanitary products • B oosting the presence of beneficial fauna • P lanting beekeeping flora in places with good exposure to the sun • Boosting the use of native plants • D iversifying plant species and taking account of the range of flowering to cover most of the year • A voiding the use of invasive plants as well as double- and multi-petal ornamental plants that often have no nectar or are difficult to access • Putting up hotels for bees and solitary wasps • Putting up insect spirals to encourage solitary bees nesting on the ground • Putting up watering troughs • Leaving certain areas of parks and gardens at rest, to boost the flowering of their plants and thereby encourage pollinating insects. • M aking mowing less frequent and increasing cutting heights 124 125 ANNEXE 3 BEEKEEPING FLORA TREES SHRUBS AND CLIMBING PLANTS Scientific name Common name Scientific name Common name Acer campestre Field maple Anthyllis cytisoides N/A Acer monspessulanum Montpellier maple Arbutus unedo Strawberry tree Acer negundo Box elder Asparagus officinalis Wild asparagus Acer opalus Italian maple Bupleurum fruticosum Shrubby hare’s ear Acer platanoides Norwegian maple Buxus sempervirens Boxwood Ceratonia siliqua Carob tree Calluna vulgaris Common heather Citrus aurantium Seville orange tree Cistus albidus Grey-leaved cistus Citrus limon Lemon tree Cistus clusii Cistus clusii Eucalyptus camaldulensis Murray red gum Cistus crispus Curled-leaved rock rose Eucalyptus globulus Tasmanian blue gum Cistus ladanifer Gum rockrose Olea europaea Olive tree Cistus monspeliensis Montpellier cistus Populus alba White poplar Cistus salviifolius Sage-leaved rock-rose Populus × canadensis Grey poplar Crataegus monogyna Common hawthorn Populus nigra Black poplar Dorycnium pentaphyllum Prostrate Canary clover Populus tremula Aspen Erica arborea Tree heath Prunus armeniaca Armenian plum tree Erica multiflora Heather Prunus avium Wild cherry tree Hedera helix Common ivy Prunus cerasifera Purple-leaf cherry plum tree Hyssopus officinalis Hyssop Prunus domestica Plum tree Ilex aquifolim Common holly Prunus dulcis Almond tree Laurus nobilis Sweet bay Prunus mahaleb Mahaleb cherry Lavandula angustifolia Lavender Prunus persica Peach tree Lavandula latifolia Broadleaved lavender Pyrus communis Common pear tree Lavandula stoechas Spanish lavender Pyrus malus Apple tree Marrubium vulgare Japanese mock orange Quercus cerrioides Turkey oak Prunus spinosa Blackthorn Quercus faginea Scarlet oak Quercus coccifera Scarlet oak Quercus ilex Holm oak Rhamnus alaternus False olive Quercus pubescens Downy oak Rosa canina Dog-rose Quercus robur English oak Rosa rubiginosa Evergreen rose Quercus suber Cork oak Rosa sempervirens Evergreen rose Robinia pseudoacacia White acacia Rosmarinus officinalis Rosemary Salix alba White willow Rubus ulmifolius Elmleaf blackberry Salix atrocinerea Grey willow Salvia microphylla Baby sage Salix babylonica Chinese weeping willow Salvia officinalis Sage Salix elaeagnos Hoary willow Sarothamnus scoparius Scotch broom Tilia cordata Small leaved lime Satureja montana Winter savory Tilia platyphyllos Large-leaved lime Source: www.floracatalana.net/llistes/flora-apicola 126 127 HERBACEOUS PLANTS Scientific name Common name Scientific name Common name Spartium junceum Spanish broom Asphodelus fistulosus Hollow-stemmed asphodel Thymus serpyllum Wild thyme Borago officinalis Borage Thymus vulgaris Common thyme Centranthus ruber Kiss-me-quick Ulex parviflorus Gorse Chichorium intybus Common chicory Vitex agnus-castus Chaste tree Daucus carota Wild carrot Dittrichia viscosa False yellowhead Source: www.floracatalana.net/llistes/flora-apicola Diplotaxis erucoides White rocket Echium vulgare Viper’s bugloss Erucastrum nasturtiifolium Watercress-leaved rocket Galactites tomentosa Purple milk thistle Hyssopus officinalis Hyssop Medicago sativa Alfalfa Melilotus albus Bokhara clover Melissa officinalis Lemon balm Mentha suaveolens Apple mint Mentha pulegium European pennyroyal Ocimum basilicum Basil Origanum vulgare Orenga Origanum majorana Marjoram Papaver rhoeas (pollen) Field poppy Tanacetum vulgare Tansy Taraxacum officinale Common dandelion Trifolium arvense Hare’s-foot clover Trifolium pratense Red clover Mediterranean buckthorn (Rhamnus alaternus) Source: www.floracatalana.net/llistes/flora-apicola Kiss-me -quick (Centranthus ruber) 128 129 ANNEXE 4 MEDITERRANEAN DRY GRASSLANDS Exposure to the sun is a factor that determines the presence of Mediterranean dry grasslands and which gives rise to high-temperature conditions and a strong summer dryness that favours grasses perfectly adapted to this climate. The most representative of these communities are thatching grass (Hyparrhenia hirta) and Dry grasslands are plant communities of great biological and landscape inter- Mediterranean false-brome (Brachypodium retusum). They constitute respec- est, many of which, as seen in peri-urban areas, can appear as impoverished and tively the dry fields of common thatching grass and Mediterranean false-brome deteriorated spaces. But the fact is, these open spaces often have a landscape thickets, plant communities associated with the African savannah and which heterogeneity that include other plant formations, such as the remains of old find their northern distribution limits in Catalonia. agricultural crops, bramble patches, stone pine (Pinus pinea) groves and urban- ised centres, and therefore offer a mosaic of plants that are extremely useful for They make up two herbaceous layers: a higher one dominated by common thatch- biodiversity. ing grass and a second, lower one, dominated by Mediterranean false-brome occupying the remaining spaces free of common thatching grass. The two com- munities are notable for their yellowish summer colouring, which needs to be reclaimed as part of our Mediterranean landscape. You can find other species associated with these communities, whose notable representatives include: • Fennel (Foeniculum vulgare) • Fringed rue (Ruta chalepensis) • Spanish broom (Spartium junceum) • Sage-leaved rock-rose (Cistus salviifolius) • Flax-leaved daphne (Daphne gnidium) • Yellow rest-harrow (Ononis natrix) • Mediterranean stonecrop (Sedum sediforme) • Mediterranean phagnalon (Phagnalon saxatile) • Purple milk thistle (Galactites tomentosa) • Three-tooth-leaved Globularia (Globularia alypum) Dry fields of common thatching grass (Hyparrhenia hirta). Tres Turons • Mallow bindweed (Convolvulus althaeoides) Dry fields of common thatching grass on Montjuïc Mediterranean dry grasslands along the borders of Carretera de Mediterranean false-brome (Brachypodium retusum) Common thatching grass (Hyparrhenia hirta) cliff. Photo: Teresa Franquesa les Aigües. Collserola 130 131 Note that such open environments are becoming extremely useful for many groups of fauna. So, for example, they provide reptiles with a suitable site for sunning themselves. The Catalonian wall lizard (Podarcis liolepis), the large psammodromus (Psammodromus algirus), the ladder snake (Rhinechis scalaris) and the Montpellier snake (Malpolon monspessulanus) are some of the species that can be found in these environments. Insectivorous birds such as the African stonechat (Saxicola torquata) and the streaked fantail warbler(Cisticola juncidis) are typical of these environments, not to mention the European goldfinch (Car- duelis carduelis), the European serin (Serinus serinus) and other finches that also use these spaces, especially in the winter, for feeding on the seeds produced by the plants there and which group together in large flocks for that purpose. Three-tooth-leaved Globularia (Globularia alypum) Yellow rest-harrow (Ononis natrix) Common kestrel (Falco tinnunculus) The common kestrel (Falco tinnunculus), a small bird of prey, is also very closely linked to these open environments, which offer it opportunities for feeding on mice, lizards and insects. Kestrels can often be seen hovering in the air as they look for prey. Mediterranean stonecrop (Sedum sediforme) 132 133 INDEX INTRODUCTION 136 CONSERVATION INITIATIVES Non-use of herbicides or phytosanitaries 138 Composting 140 IMPROVEMENT INITIATIVES Creating shrubby and herbaceous borders 142 Moderately pruning the environment’s shrub layer and lined trees 144 Ecological farming 145 Making some plots of land fallow 146 Strengthening walls and hollows 148 Boosting the presence of bees 149 Putting up nest boxes or bat towers 150 ANNEXE 1 Useful plants for beneficial fauna 152 ANNEXE 2 Border and hedge vegetation 160 ANNEXE 3 Intercropping 162 ANNEXE 4 Crop-rotation systems 166 ANNEXE 5 Mulch and manure 170 135 CITY ALLOTMENTS INTRODUCTION ANNEXE Allotments provide rich ecosystems thanks to their wide variety of plants and Central role of users animals. They are especially useful in urban and peri-urban contexts, given that they offer green-area alternatives to parks and gardens and thereby extend the Whether urban allotments are correctly managed depends mainly on users. Mu- number of spaces available for developing biodiversity. Allotments attract all nicipal workers performing maintenance tasks are also responsible here, though kinds of fauna: invertebrates, birds, small mammals etc. The presence of such to a lesser extent in such cases: they only work on the plants located around animals, far from being a nuisance, make a decisive contribution towards the the allotment. Both the former’s and the latter’s initiatives have to be developed equilibrium of this habitat. So, for example, some birds feed on larvae or insects within a coherent framework if the allotment is to benefit as a whole. that are harmful to vegetables. Likewise, amphibians, reptiles and mammals, as well as certain insects - such as ladybirds - help to keep horticultural pests at The central role of citizens in managing allotments represents a great advantage bay. when it comes to raising awareness of the importance of biodiversity in the city. Barcelona launched a participatory programme at the start of the 1990s aimed at To ensure the feasibility of such an equilibrium, a series of basic regulations have people over the age of 65. The goal was to include them in environmental-improve- to be applied to bring about certain conditions around the allotment which attract ment activities by cultivating vegetables in a network of 15 urban allotments, fauna: A suitable presence and arrangement of shrubs, fruit trees and ruderal following the principles of biological farming. This network is being enriched with plants at the borders of the allotment will clearly contribute towards achieving eleven allotments located on unoccupied land, managed by organisations from this goal. Likewise, we must avoid the use of herbicides and pesticides which can the city, and with other community or family allotments located on courtyards, end up introducing toxins into the plants and killing small invertebrates, there- terraces and balconies, not to mention the more than 200 school allotments that by altering food chains. The interactions necessary for this ecosystem would be are being developed under the More Sustainable Schools Programme. All in all, it weak or non-existent without all these regulations and their derived practices. establishes leisure, socialisation and even educational spaces through an activi- ty that had appeared to have almost been forgotten on the urban scene, after the great economic and urban-planning changes of the 20th century. Urban allotments link the city to its not-so-distant and well-documented past , where farming activities used to occupy the Barcelona plain and a good part of the urban centre. The purpose behind such activities in today’s globalised world is to contribute food and, above all, encourage city residents’ contact with nature, in a context that promotes civic-minded behaviour and knowledge. Can Cadena La Trinitat’s allotment 136 137 CONSERVATION INITIATIVES Non-use of herbicides and phytosanitaries to boost the presence of useful fauna in allotments and their borders Chrysopa (Chrysopa sp.) Can Mestres’ urban allotments The ruderal plants that often accompany ur- all, bats, which consume large numbers of in- ban allotments therefore need to be assessed. sects. The allotment must have a plant struc- Maintaining this type of vegetation helps to ture that attracts insectivorous birds and, boost the allotment’s biodiversity and control where possible, nest boxes should be put out the crop’s pests. In that regard each group of for bats. That would increase the eco-system’s fauna plays its role in controlling the others, complexity and contribute to maintaining the so reaching a natural equilibrium in the eco- natural balance between nature and the vari- system. (See annexe 1: Useful plants for ben- ous groups of fauna. eficial fauna). > Planting plant species that attract benefi- The maintenance work on these border plants cial fauna, whether within the crops or in the is carried out during their dormant period. allotment’s environment. (See annexe 1: Use- Germanetes land plot Where action outside this period is necessary, ful plants for beneficial fauna). the flowering period must be avoided and, if Description/application bramble bushes are present, the birds’ nesting > Uprooting weeds by hand or with the aid of period (March-July). a hoe that appear on the cultivated land. It is This is about promoting the presence and de- > Conserving border plants, grasslands and advisable to remove such weeds before they velopment of beneficial fauna populations to bramble bushes that are found in allotments > Controlling populations of invertebrate seed. combat the pests and diseases that can ap- and which constitute a reservoir of beneficial fauna through insectivorous birds and, above pear in crops. The phytosanitary state of crops fauna. depends to a great extent on the degree of development of such beneficial fauna, which Green lacewings, for example, are easily rec- keeps harmful insect populations at accept- ognisable insects given their long, green body, able levels through direct predation or parasit- transparent wings with very pronounced ism. The success of beneficial fauna depends nerves, prominent golden eyes and long an- on many factors, including the development of tennae. They are part of this beneficial fauna the environment’s vegetation, the crops them- of great use for horticulture, seeing as their selves, climate etc. But the most important larvae feed on many of the pests that usually factor, however, is to avoid using herbicides affect allotments (aphids, whitefly, red spider and phytosanitary products that have an ad- mites, thrips, scale insects and caterpillars). verse effect on development. In their adult stage, some species of green lacewings are predators while others, by con- trast, feed on nectar and pollen. Pot marigold (Calendula officinalis) Camomile (Matricaria recutita) Can Soler’s urban allotments 138 139 CONSERVATION INITIATIVES Composting to have an organic fertiliser that improves > Fitting out a place for composters nearby the crops to make it easier to transport the the soil’s structure and boosts the presence of soil fauna materials. The process for obtaining compost lasts between seven and nine months. Can Soler’s urban allotments Description/application A whole series of invertebrates are involved in the decomposition process of the organic material, including worms, cockroaches, myriapods and other insects, which, when feeding on such organic matter, break it up into tiny pieces and en- able microorganisms, mainly fungi and bacteria, to complete the decomposition process, with humus as the final product. Note that the action of these microor- ganisms releases nutrients into the soil, which are directly assimilated by plants and, moreover, give rise to a mineralisation process, once the humus is produced, which also ends up helping to increase the soil’s fertility. When organic matter is incorporated into the soil, extremely useful soil fauna are also included, whose activity improves the structure of the soil (nutrient-retention capacity, aeration, drainage etc.,) and increases its fertility, while boosting the food chain. Hort de Torre Melina 140 141 IMPROVEMENT INITIATIVES Creating shrubby and herbaceous borders to provide > Planting trees around allotments to pro- (See Shrub groups and hedges. Annexe 3: tect crops from wind effects and reduce Shrubby plants of use to fauna and Urban Al- a vegetation that promotes biodiversity evapo-transpiration rates, thereby increasing lotments. Annexe 2: Border and hedge vegeta- productivity. In addition, mature fruit provide tion). food for many groups of fauna. Mas Ravetllat’s allotments Hort de l’Avi Description/application Ensuring these borders offer a diverse vege- tative structure with herbaceous and shrubby plants and, if possible, fruit trees. The following criteria have to be borne in mind: • Using native plant species which offer great- er interaction with local fauna. • Creating diversity using several plant spe- cies. Can Mestres’ urban allotments Can Mestres’ allotment 142 143 IMPROVEMENT INITIATIVES IMPROVEMENT INITIATIVES Moderately pruning the environment’s shrub layer Ecological farming to improve the soil’s fertility and and lined trees so the allotment can enjoy the benefits maintain the ecosystem’s natural equilibrium that fauna bring Can Mestres’ urban allotments Can Mestres’ allotment Description/application Description/application Nesting, hibernation, sheltering and feeding > Such pruning work, and indeed any main- This involves carrying out a series of farming > Mulching: this involves covering the culti- places need to be provided for several spe- tenance work in general, will be performed practices that enable improvements to the vated land with a protective layer, preferably cies of animals, vertebrates and invertebrates during the winter. Where any action is neces- soil’s structure and fertility while also com- made up of organic matter. (See annexe 5: alike. sary at other times of the year, it will have to bating outbreaks of pests and disease among Mulch and manure). avoid the nesting period of the area’s birds. the crops. It is therefore advisable to apply > The environment’s vegetation has to be them. > Contributing organic matter to improve the pruned so plant structures continue to act as > Where accumulated rubbish has been soil’s structure and fertility. By incorporating a shelter for fauna at all times. Where the large spotted, the environment’s plants will have to > Intercropping: this involves cultivating sev- organic matter into the soil through compost development of such plants require contain- be cleaned. Where the site’s features so allow, eral species of plants in the same plot of land or manure, we are activating its biology, in- ment action, two initiatives must be planned such cleaning work must avoid any removal of while also obtaining a greater yield. (See an- jecting a whole series of fauna (bacteria, fun- within a period of five years, so that areas can leaves, to encourage the presence of inverte- nexe 3: Intercropping). gi and invertebrates) that will take part in the be maintained without pruning and act as brates in the litterfall. soil-formation process. shelter for fauna. > Crop-rotation systems: this involves alter- nating crop species in the same plot of culti- vated land. (See annexe 4: Crop-rotation sys- tems). 144 145 IMPROVEMENT INITIATIVES Making some plots of land fallow to improve the > Another option is to plant alfalfa (Medica- inside from the Rhizobium genus responsible go sativa) or other species from the Fabaceae for carrying out this nitrogen fixation. Alfalfa ecological equilibrium (legume) family on these plots of fallow land. and other legumes (beans, peas, red clover These legumes have a capacity to capture at- etc.,) can therefore be used as a green fertil- mospheric nitrogen and fix it in the soil in such iser by incorporating the aerial parts of the a way that it can be absorbed by plants. plants into the soil to improve its fertility. If such plants are used as a green fertiliser, it is They are able to do that thanks to the presence advisable to mow them before they flower, as of small protuberances in their roots known it is then that they contain their highest levels as nodules which house symbiotic bacteria of nutrients. Can Mestres’ urban allotments Description/application > Where possible, strips or plots of cultivated land need to be made fallow for one or several seasons. These plots will be colonised by her- baceous communities that are used for feed- ing birds, invertebrates and small mammals. Maintenance clearing work has to be carried Nodules in bean roots out on the land plots, where appropriate, bear- ing in mind, however, that spring flowers are attractive to pollinating insects and become extremely useful for feeding granivorous birds in the autumn. Can Soler’s urban allotments 146 147 IMPROVEMENT INITIATIVES IMPROVEMENT INITIATIVES Strengthening walls and hollows to ensure Boosting the presence of bees to encourage shelters are available for fauna pollination Tres Pins Plant Nursery’s apiary Stone wall Can Soler’s allotments Description/application Description/application Barcelona has two municipally run apiaries • T he boxes should be mounted on benches Care must be taken not to damage elements that can provide shelter for fauna, that house bees which have been moved from or other structures to avoid their direct con- such as walls, hollows and trunks, which will be used not just by insects, arach- the city’s public roads as a result of incidents. tact with the ground and prevent their bee nids and other invertebrates but also by lizards and small birds. Where such el- Note, in any case, the ecological function car- colonies from being affected by varroa mites ements are not present, it may be worth creating walls by piling up stones of ried out by the bees in pollinating plants and (Varroa destructor), which parasitise them, different sizes. crops. It is therefore advisable to boost their and other diseases associated with humidity. presence. • Apiaries should be positioned in open spac- > It is a good idea to install apiaries provided es where there are a considerable number of this is permitted under the current regulations flowers. It is advisable for such flowers to be in force and where the area’s ecological fea- under a kilometre away so as to increase the tures are suitable. The following factors need apiary’s productivity and prevent excessively to be taken into account in apiary sites: long journeys. • It is important for apiaries to face south or • It is also advisable for the apiary to be near- south-east so they receive the maximum by water points. Bees use water for several amount of sunshine and temperatures inside purposes, notable among which are feeding the boxes can therefore be maintained. It is their young and the queen and cooling the also important for the apiaries to be located colony. Where there are no water points, wa- in areas sheltered from the wind and for the tering troughs can be put up and floating el- spaces in front of the boxes to be kept clean ements added such as cork to protect bees Jardins d’Elvira Farreras Valentí (free of plants), to enable the bees to easily from drowning. enter and leave them. 148 149 IMPROVEMENT INITIATIVES Putting up nest boxes or bat towers to boost the allotment’s natural balance Bat nest box Bat-nest tower in the Can Cadena Allotment. Description/application A good measure for promoting biodiversity is to put up nest boxes in buildings close to the urban allotments or, failing that, to put up towers specifically de- signed for these mammals. Bats consume large quantities of insects, given that in a single night they are capable of consuming 60% of their weight in insects and therefore play an important ecological role in regulating insect populations, some of which can become pests to horticultural crops and green spaces in gen- eral. On the other hand, they also play a very notable ecological role in eliminating the viruses that are carried by the mosquitoes they feed on. Boosting the pres- ence of bats in the city benefits urban biodiversity and helps to improve public health and well-being. Common pipistrelle. Photo: Xavier Puig 150 151 ANNEXE 1 ANNEXE USEFUL PLANTS FOR BENEFICIAL FAUNA RAGWORT (Senecio jacobaea) Description: This is a rural plant that flowers during the sum- mer season. Its yellow flowers are grouped in clusters and have a SWEET ALYSSUM (Alyssum maritimum) high pollen and nectar content. Description: This is an annual herbaceous plant native to the Medi- Action: It is used as a direct source of feeding for pollinators in terranean region which spontaneously appears along roadsides. general and indirectly for omnivorous predators such as lady- Its flowers are small, white and grouped together in clusters. They birds and parasitic wasps. can appear throughout the year, though above all in the autumn and winter. Action: It is advisable to plant it along allotment borders to attract pollinating insects, mainly diptera from the hoverfly family, whose larvae feed on preying aphids. The adults of these flies find an im- MINT (Mentha sp.) portant source of nectar and pollen in sweet alyssum during a com- plicated time of the year, the autumn-winter period, when there are Description: This is a plant that grows from fast-spreading rhi- usually few flowers. zomes under low-light, humid conditions and in rather clayey soils. Its flowers are grouped in blue clusters. Action: Mint flowers offer a quantity of pollen and nectar that attracts a large variety of insects, from pollinators to predators, FALSE YELLOWHEAD (Dittrichia viscosa) not to mention parasitic hymenoptera. It is useful, then, to re- serve a shady space for mint inside a piece of cultivated land. Description: This is a very rural, semi-woody plant, native to the They need to be controlled from spreading by being planted, for Mediterranean region and which can be found along roadsides, example, in fruit-tree pits. abandoned fields and turned-over land. On the other hand, it has been confirmed that intercropping mint It needs no maintenance; in fact, it grows perfectly well in soils that with cabbage within a plot of cultivated land is highly favourable, are poor in nutrients and has few water requirements. as the mint’s essential oils act as a repellent against the well- It is considered a colonising plant, given its leaves’ high toxicity, re- known large white butterfly (Pieris brassicae), whose caterpillars pelling herbivores, and the fact that its roots are capable of secret- feed on cabbage leaves. ing phytotoxic substances that prevent other species from estab- lishing themselves nearby. It is advisable, then, to position it along borders where plants can grow. It presents yellow flowers that appear in the autumn and feed beneficial fauna with their pollen and nectar during a time of the year when food resources are scarce. Its sticky leaves, lending the species its Latin name, provide a strategy for controlling evapo-transpi- ration, seeing as such stickiness gives the plant a higher resistance to dryness. Action: False yellowhead is useful for olive and critic tree crops, given that it is used by a species of insect (Myopsites stylata), from the same family as the olive fruit fly (Bactocera oleae) and the Mediterranean fruit fly (Ceratitis capitata) whose larvae grow inside false yellowhead fruit. These larvae are parasitised by a whole series of wasps which in their adult stage parasitise olive and Mediterranean fruit flies and therefore help to keep the numbers of these agricultural pests down to acceptable levels. On the other hand, false yellowhead flowers attract a large number of insects, some of which prey on whitefly, so helping to achieve a natural balance between invertebrate populations. 152 153 ROSEMARY (Rosmarinus officinalis) BORAGE (Borago officinalis) Description: This is a shrubby, perennial plant, native to the Description: Annual plant typical of borders, allotments, grass- Mediterranean region and very useful for flowers. It is clear in lands and damaged environments, used since ancient times as that sense that the flowering season of these plants represents a vegetable. It flowers in the spring. a very important factor when it comes to designing strategies for attracting beneficial fauna, and rosemary is a good example Action: Borage is especially attractive for pollinating insects, as of that. Its staggered flowering continues practically throughout it is regarded as one of the most melliferous plants in the Medi- the year and offers many possibilities for boosting the presence terranean region. Its flowers have a high nectar content that at- of beneficial fauna in our crops. tracts pollinators such as honey bees as well as parasitoid hy- menoptera and generalist predators of insects that are harmful Action: Rosemary is a melliferous plant that not only attracts to our crops. In that regard, it is one of the best plants for accompanying our crops given its powers European honey bees (Apis mellifera) but also a large number of in attracting beneficial fauna. pollinators and pest parasitoids. Its flowers also attract preda- tors of thrips and mites which use rosemaries as a plan for shel- tering or feeding. Its essential oils act as a repellent for several types of allotment pests, such as whitefly. VIPER’S BUGLOSS (Echium vulgare) Description: Annual plant native to the Mediterranean region that can be found along roadsides and damaged land. It derives its common name from its fruit’s resemblance to the head of a COMMON THYME (Thymus vulgaris) viper. Blossoming in the spring, its blue flowers attract a large number Description: A perennial, woody and low-lying plant with leaves of pollinating insects. that give off an aroma noted for its essential oils. Its whitish-pink Its toxicity gives it a defence mechanism against herbivores and flowers blossom in the spring. It is a rural plant perfectly adapt- phytophagous insects. ed to the Mediterranean climate and grows in full sunshine on rocky and alkaline terrain. Action: The high content of pollen and nectar in its flowers at- tracts a large number of pollinating insects as well as a whole Action: The essential oils in its leaves act as a repellent to sever- series of arachnids, which make up one of the most important al species of insects that are harmful to crops, including aphids, groups in regulating the biological populations of pest insects whitefly and large white. that can affect our crops. Thyme also attracts a whole series of pollinating and parasi- toid insects. Some of these parasitoids are solitary adult wasps whose diet consists of pollen and nectar; but when they feed their offspring, they then capture a variety of invertebrates such as grasshoppers and caterpillars, which they take to their nests (nor- mally on the ground) and use for feeding their larvae offspring. 154 155 OTHER PLANTS THAT ATTRACT USEFUL FAUNA INCLUDE: • Basil (Ocimum basilicum) It attracts bees and repels tomato whitefly. • D ill (Anethum graveolens) It attracts hoverflies. • Aster (Aster sp.) This attracts green lacewings, whose larvae feed on several species of aphids, thrips, scale insects and caterpillars, as well as the eggs of various species of insects. Adult green lacewings can be predators, otherwise they feed on nectar and pollen. • C leavers (Galium aparine) Garden nasturtium (Tropaeolum majus) This repels greenfly (from the family Cicadellidae) which often attack aromatic plants such as rosemary and thyme. • Wild angelica (Angelica sylvestris) It attracts insects from the family hoverfly. Its larvae prey on aphids whereas its adults are pollinators. • Marigold (Calendula officinalis and Calendula arvensis) This attracts parasitoid hymenoptera such as wasps, which parasitise several Camomile (Matricaria recutita) species of aphid. Its flowers contain nectar and therefore attract a large number of pollinating insects such as bees. It also repels nematodes. • Prostrate Canary clover (Dorycnium pentaphyllum) Its flowers’ melliferous content attracts numerous pollinating insects. • Garden nasturtium (Tropaeolum majus) It is a good idea to plant garden nasturtium in fruit tree pits or among allotment plants as they act as repellents against aphids, whitefly, true bugs, snails and nematodes. It attracts pollinating insects. Pot marigold (Calendula officinalis) • French marigold (Tagetes patula) It can be planted between horticultural plants and fruit trees to protect against nematodes and attract green lacewings. • L avender (Lavandula sp.) This attracts pollinating insects and repels pests such as rose bush aphids. • Fennel (Foeniculum vulgare) French marigold (Tagetes patula) It attracts insects from the hoverfly family. 156 157 • Hyssop (Hyssopus officinalis) This repels caterpillars, aphids and snails. Its flowers’ nectar attracts numerous pollinating insects such as bees and butterflies. • C amomile (Matricaria recutita) This attracts hoverflies and bees. A great producer of pollen. • Yellow rest-harrow (Ononis natrix) This is a melliferous shrub that attracts many pollinating insects. It attracts beneficial fauna such as true bugs, some of whose species prey on pests. It can also be used as a host plant for pests such as aphids. It is therefore a good Lemon balm (Melissa officinalis) idea to plant this species in allotment borders seeing that it draws pests over to it, thereby protecting horticultural plants from them, on the one hand, and, on the other, attracts predators of pests, such as ladybirds and lacewings. • F ield milk thistle (Sonchus arvensis) Its flowers attract numerous pollinating insects. It acts as a crop-pest host plant. • Marjoram (Origanum majorana) Hyssop (Hyssopus officinalis). Photo: Wikimedia Its flowers attract bees and butterflies. • Lemon balm (Melissa officinalis) Its flowers attract bees. • Y arrow (Achillea millefolium) This is a good plant for attracting useful fauna such as hoverflies (which prey on aphids) and green lacewings. Its flowers attract bees, among other things. It Daisies (Aster sp.) stimulates the production of essential oils in aromatic plants. • Wild carrot (Daucus carota) Its flowers produce a nectar that attracts hoverflies which prey on aphids and whitefly. • Rue (Ruta graveolens and Ruta chalepensis) It repels aphids, slugs, flies, mosquitoes and nematodes, among other things. Its flowers attract hoverflies. Sage (Salvia officinalis) • Sage (Salvia officinalis) Its flowers attract honey bees and bumblebees. It can be planted among cabbages given its repellent properties against large white butterfly (Pieris brassicae) caterpillars. Source: Bichelos, Control Biológico S.L. www.bichelos.com Fennel (Foeniculum vulgare) 158 159 ANNEXE 2 BORDER AND HEDGE VEGETATION Shrubs Associated fauna Lianas Associated fauna Its fruit is eaten by birds. Its nectar-producing rough bindweed (Smilax aspera) Its fruit provides food for birds. Blackthorn (Prunus spinosa) flowers attract butterflies, bees and other insects. It provides nesting and food for several species of birds and is also used as shelter by several Common lilac (Syringa vulgaris) Its flowers attract insects. Common ivy (Hedera helix) groups of fauna (invertebrates and vertebrates alike). Its fruit is eaten by birds. Its flowers attract Laurustinus (Viburnum tinus) insects. Fragrant virgin’s bower (Clematis flammula) This is used as a shelter by many invertebrates. Common dogwood (Cornus sanguinea) Its fruit is eaten by birds. Grapes are the food for many invertebrates and Common grape vine (Vitis vinifera) vertebrates. Its fruit is eaten by birds. Its flowers attract Elderberry (Sambucus nigra) insects. Bramble bushes and low scrub Associated fauna Grasses Associated fauna It provides nesting and food for several species Mediterranean false-brome (Brachypodium Several species of granivorous birds feed on its of birds and is also used as shelter by several retusum) seeds. Its flowers attract insects. Elmleaf blackberries (Rubus ulmifolius) groups of fauna (invertebrates and vertebrates alike). Several species of granivorous birds feed on its Common thistles (Cirsium vulgare) seeds. Its flowers attract butterflies and other Wild asparagus (Asparagus acutifolius) This attracts insects. insects. Its fruit is eaten by birds. Its flowers attract Several species of granivorous birds feed on its Butcher’s-broom (Ruscus aculeatus) Wall barley (Hordeum murinum) butterflies and other insects. seeds. Its flowers attract insects. Its fruit is eaten by birds. Its flowers attract Several species of granivorous birds feed on Dog-rose bush (Rosa canina) butterflies and other insects. White rocket (Diplotaxis erucoides) its seeds. Its flowers attract insects and other invertebrates. It provides nesting and food for several species of birds and is also used as shelter by several Evergreen rose bush (Rosa sempervirens) groups of fauna (invertebrates and vertebrates alike). Source: “Manual for conserving biodiversity in agrarian habitats”. Generalitat of Catalonia Catalan Environment and Housing Ministry. 160 161 ANNEXE 3 INTERCROPPING There are plants that help one another when they are put in contact, referred to > Optimising space: this increases planta- as positive associations, and others that harm one another, whether by direct tion densities and uses plants of a different competition or because the roots of some plants secrete substances that have structure (vertical-growth crops and horizon- an adverse effect on the growth of the plants they share their spaces with, re- tal-growth crops) in such a way as to enable ferred to as negative associations. better soil cover and better harnessing of sun- light while keeping the land’s humidity con- So, for example, there are well-known positive associations between vegetables stant. and certain aromatic plants which help to keep undesired insects at bay, thanks to the repellent action of their essential oils. Such is the case with basil (Oci- Examples: Maize + squash, climber beans + mum basilicum) and rue (Ruta graveolens), which protect against proliferations cucumbers. of aphids on tomatoes and peppers. And with French marigold (Tagetes patula), which repels aphids and whitefly. In this case it has a triple action: its aroma > Can Mestres’ urban allotment Time optimisation: horticultural short-li- repels whitefly; its roots release chemical repellents and its nectar attracts lady- fecycle plants are grown in free spaces left by birds, hoverflies and wasps, which prey on aphids and their larvae. long-lifecycle plants. Examples: lettuces + to- mato plants, cabbages + broad beans. • P lants with supplementary nutritional needs or different root systems. These allow the most to be made of the soil’s nutrients. Examples: • Cabbages and cauliflowers intercrop well with broad beans, peas or string beans. Leg- umes introduce nitrogen into the soil, which helps the vegetative part of the other spe- cies to grow. Can Mestres’ urban allotment • If we intercrop carrots and lettuces, the former will grow in 50 cm of soil, absorbing mainly potassium, while the roots of the lat- ter will grow in the first 30 cm in search of Parsley nitrogen. Note: (Petroselinum crispum) – Root vegetables: require potassium. – Leaf vegetables: require lots of nitrogen Parsley (Petroselinum crispum) which also repels whitefly. So it is also a good to grow large and healthy leaves. idea to plant some in the plot of land being cultivated. – Fruit vegetables: need phosphorus for producing large and tasty fruit. The goal then is to make the most of the inter-relations between plants and be- tween plants and animals and of the plot of land being cultivated under the fol- lowing criteria: 162 163 Table of various protective and repellent plants: Plant Beneficial effects Basil General insect repellent Camomile Attracts pest-parasite hymenoptera Garden nasturtium Controls whitefly Repels nematodes, aphids and whitefly. Also attracts hoverflies, French marigold wasps and ladybirds by producing nectar. Common flax Repels Colorado potato beetles Mint Controls ants and cabbage white fly Sage Repels large whites and carrot flies Table of various protective and repellent plants: Plant Beneficial effects Colorado potato beetles show a preference for this plant over Aubergine potato crops. Given the preference that the scarce bordered straw (Helicoverpa Maize armigera) has for it over tomato plants, it can be used with the Mas Ravetllat latter’s crops. Attracts numerous pests. (Make sure it is planted in greenhouses, Tree tobacco as it can be a source of powdery mildew). > Intercropping with legumes: nitrogen fix- Useful plants intercropping crops for obtain- ation. ing phytosanitary advantages: Examples: it is also usual to plant string • Bait plants: are more attractive than their in- beans, maize and squash on the same plot of tercropped plants to a specific pest. land. String beans introduce nitrogen to the soil, maize is used as a growing guide for the • P rotective plants: act as a shelter or source string beans, whereas the squash carpets the of food for useful fauna, thereby boosting soil and keeps it at a constant level of humidi- their presence and activities. ty thanks to the shade it casts. • Repellent plants: release pest-repelling sub- stances. Source: ”Practical guide to ecological horticulture: school allotments”. Barcelona City Council.Schools Agenda 21. 164 165 ANNEXE 4 CROP-ROTATION SYSTEMS Crop rotations help to maintain the balance of nutrients in plots of cultivated So, plot 1 will only have an annual plantation established, at the start of the land and make it hard for pests and diseases to establish themselves, as crops spring, with long-lifecycle plants. Even so, the land can be prepared in the winter are not repeated from one season to another. In any case, crop-rotation systems for purposes of its gradual fertilisation. require the cultivated area to be organised into four completely bounded plots. There are basically two types of crop rotations: Plot 1 Nightshades Tomatoes, peppers and aubergine Botanical families This involves establishing a plantation calendar for each plot in four-year cycles, Plot 2 can have several harvests of carrots and onions given their very short life- grouping together annual plantations for botanical families. Each botanical fam- cycle while the other crops will only be harvested once. ily presents various nutritional requirements so that if we do not repeat a planta- tion in a plot for a period of four years we can keep the soil fertile. Plot 2 This is the system proposed under Gaspar Caballero de Segovia’s Parades en Umbelliferae Carrot, celery and parsley Crestall method. Liliaceae Onions, leaks and garlic Plot 3 can have spinach or Swiss chard sown in the autumn, given their long li- Plot First year Second year Third year Fourth year fecycles; several harvests of lettuce and, once the good weather arrives, cucum- Composites Umbelliferae 1 Nightshades Legumes - Crucifers bers and courgettes. Chenopodiaceae Gourds Liliaceae Composites Umbelliferae Legumes 2 Nightshades Chenopodiaceae Liliaceae Crucifers Plot 3 Gourds Composite Lettuce and common chicory Composites Umbelliferae Legumes 3 Nightshades Chenopodiaceae Gourds Liliaceae Crucifers Chenopodiaceae Swiss chard and spinach Legumes Composites Umbelliferae 4 Nightshades Gourds Cucumber and courgette Crucifers Chenopodiaceae Gourds Liliaceae Finally, plot 4 can have broad beans and peas sown at the start of the winter and Source: ”Practical guide to ecological horticulture: school allotments”. cabbage and cauliflower too, in the autumn. Barcelona City Council. Schools Agenda 21. Plot 4 Legumes String beans, peas and broad beans Crucifers Cabbage, cauliflower, broccoflower and radish The crops will be rotated the following year, with the plantations made in plot 1 moving to plot 2; those in plot 2 to plot 3; those in plot 3 to plot 4 and those in plot 4 to plot 1. 166 167 Nutritional requirements The second method proposes a four-year rotation based on the nutritional re- quirements of each type of plant, taking into account that some have very high needs and others have average or low needs, and that some crops improve the soil’s fertility. Plot First year Second year Third year Fourth year 1 High Average Low Soil-improving crops 2 Average Low Soil-improving crops High Onions in Can Soler 3 Low Soil-improving crops High Average 4 Soil-improving crops High Average Low Plants with high nutritional requirements Plants with average nutritional needs Tomatoes, potatoes, squashes, courgettes, Aubergines, carrots, onions, spinach, cucumbers, maize, asparagus, Swiss chard, celery, lettuce, peppers, melons, watermelons, garlic, cabbage, cauliflower, artichokes, strawberries, leaks radish, parsnip and beet. and parsley. Trinitat allotment Plants with low nutritional needs Soil-improving crops that contribute nitrogen to the soil Common chicory, string beans, broad beans, lentils, peas, chick peas and soya. Green fertilisers: clover, comfrey or alfalfa. Source: ”Practical guide to ecological horticulture: school allotments”. Barcelona City Council. Schools Agenda 21. Swiss chard in Mas Ravetllat 168 169 ANNEXE 5 MULCH AND MANURE Mulch Manure Decomposition Materials Layer thickness Comments Types of manure Features Dose Comments capacity Mulched pruning Has to be fermented to eliminate Low 5 cm Very rich and balanced leftovers Sheep 0.5-2 kg/m2 seeds and pathogenic agents. When in nutrients fresh, it can burn plants. Mashed leaves and dry Average 3-5 cm Has to be fermented before it is grass Similar to sheep manure Goat 0.5-2 kg/m2 applied or mixed with horse manure to but stronger make it milder. Applied to the surface and, after 5 to Mowed lawn, green High 1 cm 10 days have passed, mixed with the Very rich in nitrogen and Has to be fermented and only leftovers from allotments first 5 cm of the soil very strong. Contains used in small quantities to avoid a high quantity of burning the plants. Hen droppings calcium and is therefore 0.05.-0.3Kg/m2 It is better NOT to use Recommended for avoiding excess not suitable for use in intensive-farming manure Straw Very low 2-3 cm humidity at the base of stems calcareous soils. Very (which contains anti-parasites, good in acid soils anti-biotics etc.) Improves the structure Compost Very high 2-3 cm It has to be properly fermented. It of the soil can be mixed with straw and leaves This is a strong manure, for better fermentation. Where soil is Rabbit where used fresh, and 0.1-0.4 kg/m2 applied to it, it is better to do that in quite acidic. the autumn so it can be worked up to the spring. A good manure, with It should be noted that the European beach, pin and other conifer tree leaves large quantities of Ideal for mixing with other manures acidify the soil, so it is not advisable to use such materials for mulching, except microorganisms and such as sheep dung or hen droppings. Horse, donkey or ass 1-5 kg/m2 quickly ferments, Goes very well on clayey soil as it where acidophilic plants are being cultivated. though a little poor in makes it spongy. nutrients. Rich in water Nor is it advisable to using mulch on plots of cultivated land in the following cas- es: • Where the sowing has to be done directly. The seeds here need bare earth and good exposure to sunlight. No mulching then until the seeds have germinated and their plants have grown a few centimetres in height • In cold and humid areas where the cultivated land needs to be capable of being warmed up by sunshine. • In areas of light and scarce rain, where good irrigation systems are unavailable, what little precipitation there is only dampens the organic mulch and fails to enter the soil. Source: ”Practical guide to ecological horticulture: school allotments”. Barcelona City Council. Schools Agenda 21. 170 171 INDEX INTRODUCTION 174 CONSERVATION INITIATIVES Cleaning ponds and minimising the impact on habitats 176 Controlling excess organic matter in ponds 178 Controlling or eliminating exotic species 180 Ensuring a balance of fauna in the ecosystem 182 Not applying phytosanitary or chemical products 184 Boosting invertebrate fauna in ponds 186 Naturalising ponds 190 Surface re-circulation of water in naturalised ponds 191 IMPROVEMENT INITIATIVES Improving environments 192 Pruning the environment’s vegetation in several stages 193 Encouraging useful flora and fauna 194 Introducing aquatic plants 196 Managing the fauna’s access to ponds 198 Managing the public’s access to ponds 199 Public information 200 ANNEXE 1 Aquatic plants at the Tres Pins Plant Nursery 202 ANNEXE 2 Useful fauna in Barcelona’s fountains and ponds 210 ANNEXE 3 List of gardens with naturalised ponds in Barcelona and their associated fauna 218 173 AQUATIC ENVIRONMENTS AND PONDS INTRODUCTION ANNEXE Aquatic ecosystems in nature play an environmental role of the first order, such Outside space as providing water for the land and subsoil and creating habitats for numerous species of plants and animals. Humid areas are considered one of the richest The space located around pools or ponds is important because of its direct influ- ecosystems in biodiversity and play a notable role in preserving amphibians, ence on the quality of the aquatic environments. Note that amphibians develop which are dropping in numbers all over the planet. in two habitats. The presence and availability of lined trees or shrubs as well as other elements –walls, rocks, plant pots, plant cover etc., – can encourage bi- When it comes to urban environments, naturalised aquatic milieus - and ponds odiversity by creating shelters and continuity spaces between water and land, in particular - provide a highly valuable, ecological habitat which, for all the lim- promoting the interaction required for all ecosystems. itations expected of their location, make a notable contribution towards main- taining and boosting biodiversity in the city. Barcelona boasts over two hundred Gardening work therefore has to be adapted to these needs. ponds and aquatic milieus that are linked to parks and gardens. It is a whole series with a large diversity of types relating to size, location and extent of natu- Ponds and aquatic environments are always a point of special attraction for vis- ralisation. There are large ones, such as the pool in the Parc de la Ciutadella and itors, which is why they make an ideal place for highlighting how ecological val- more modestly sized ones scattered throughout parks, gardens and squares, in ues are being added to aesthetic values and strengthening them. Views of flora every neighbourhood and district. Some eighty ponds and ornamental fountains are enriched when they include fauna. A complete aquatic habitat can attract in the city are currently following a naturalisation programme aimed not only more animals from other sites, such as birds, which make viewings even more of at achieving a natural balance in fauna and flora but also at making those very a pleasure by bringing quality sounds to the landscape. aquatic systems self-regulating while boosting their biodiversity. Naturalisation Such diversity demands specific attention to the uniqueness of each case. Even so, there are general ideas on good management. The first is to carry out a type of moderate cleaning that changes the habitat as little as possible. Naturalising ponds guarantees biodiversity and provides a management alternative to chlo- Turó Park’s small pond rination. Both the orderly aspect expected by the public and the space’s natural balance have to be addressed. Another key aspect of management involves monitoring the space’s plant and an- imal communities and paying special attention to those that can adversely affect the ecosystem. All food levels must be represented there if a mature and complex ecosystem is to be achieved. Hence the importance of preserving algae, inverte- brates, plants and, above all, amphibians (some of which are protected species) and, on the other hand, of controlling exotic species that harm the habitat, such as carp, goldfish and pond sliders. The balance concept also applies to organic matter, whose presence is necessary for life, only up to a certain point, but whose excess causes a reduction in oxygen levels and a drop in biodiversity. 174 175 CONSERVATION INITIATIVES Cleaning ponds and minimising the impact on > It is important to make the most of the annual cleaning to ensure the aquatic plants are maintained, divided and planted. (See annexe 1: Aquatic plants at the habitats to prevent their destruction Tres Pins Plant Nursery). > Ponds have to be emptied once a year for cleaning and maintenance work, while preserving their biota and returning it to the pond, as established under Area of Environment Instructions IA/02.02: Managing fauna in ornamental foun- tains. Note, however, that a thorough monitoring throughout the year, by con- trolling the various factors that can disrupt the balance of the pond, may make it unnecessary to empty out the pond every year. > Avoid removing all the pond’s sediment, to encourage muskgrass (Chara sp.) to take root, a native alga of very useful ecological value. Turó Park’s small pond with filamentous algae (genus Cladophora) Description/application Installing flower boxes in the Can > Has to be annually cleaned during its pe- Cadena’s pond January riod of least biological activity (November to February). February March Such action will involve: April - Removing organic matter. May - Removing filamentous algae. June - R emoving or controlling exotic fauna popu- July lations. August Filamentous algae proliferations will probably September require more frequent cleaning initiatives. In October such cases action will be taken where appro- November priate, except during the period between April December and July, which corresponds to the amphibi- ans’ breeding period, as the filamentous algae Annual cleaning Surface cleaning may contain their eggs. Amphibians’ breeding the Monestir de Pedralbes’ irrigation pond 176 177 CONSERVATION INITIATIVES Controlling excess organic material in ponds > Surface litterfall has to be removed every week with a scoop net. Organic left- overs from food also have to be looked out for and removed. to protect against eutrophication and bad smells > Visitors must be prevented from feeding pond fauna (increased organic mat- ter). Warnings should be bolstered with signage. > Trees should not be planted near toy ponds so their leaves do not fall in them. If there are already trees there, they must be suitably pruned. Where these are deciduous trees, it is worth considering the option of putting up a net during the period they shed their leaves. > Natural (plant) or artificial structures need to be put up to block organic mat- ter from entering ponds. Llac de Diagonal Mar with goldfish inside Cleaning of the Turó Park’s water lily pond Description/application An aquatic system’s organic matter decomposes through the activity of the wa- ter’s microorganisms (mainly fungi and bacteria). The end result of this process is the release of nutrients into the environment. Excess organic matter raises the concentration of nutrients dissolved in the water (eutrophication), put at the disposal of algae and other organisms which quickly use them, making their pop- ulations grow enormously. On the one hand, the activity of all these organisms consumes oxygen, thereby depleting the water’s oxygen and giving rise to anoxic conditions (lacking oxygen) that are in turn responsible for the creation of tox- ins and bad smells. On the other hand, the excessive growth of the filamentous algae blocks the entry of light, impeding the aquatic plants’ photosynthesis. So a pond’s load capacity for processing a certain concentration of organic matter must not be exceeded. 178 179 CONSERVATION INITIATIVES Controlling or eliminating exotic species to avoid > Where no naturalisation programmes are They also adversely affect the quality and permitted in such ponds, because of their transparency of the water, by eliminating zo- adverse effects on native fauna and the ecosystem features and urban context, one option is to oplankton and by increasing organic matter maintain their exotic fauna. The Parc de la Ci- concentrations with the urine and excrement utadella’s large lake and the Laberint d’Horta’s they produce during their activity. In addition, wash house offer good examples of that. Spe- by moving along the bottom of the pond, they cies such as grey herons (Ardea cinerea) use stir up its sedimentary materials, thereby re- them as feeding points. leasing sedimented nutrients and spreading them throughout the water column. Once they Despite the option for conserving gold fish or reach the surface, these nutrients lead to un- pond slider populations in certain ponds, the controlled growth of bacterial and unicellular fact is that their presence is very harmful to and filamentous algae populations, making the pond’s biodiversity, as these animals have the water considerably murkier. a very pronounced predatory behaviour and eat amphibian eggs, small tadpoles, aquatic It can therefore be said that the presence of invertebrate and, in the case of fish, zooplank- fish and turtles is incompatible with any kind ton. of pond-naturalisation programme, one of whose precise goals is to boost the biodiver- sity of these aquatic systems in accordance with certain water quality and transparen- Goldfish (Carassius carassius) Pond sliders (Trachemys scripta) cy parameters required by the urban context they are set in. Description/application Where there are amphibians in such natural- ised ponds, their populations of carp (Cyp- rinus carpio), goldfish (Carassius carassius), pond sliders (Trachemys scripta), red swamp crawfish (Procambarus clarkii), eastern mos- quitofish (Gambusia holbrooki) and generally any exotic species that may adversely affect these ecosystems will have to be removed. Where naturalised ponds do not have any amphibians, the proposal is to control their populations of carp, goldfish and pond sliders through periodic culling, to keep their popula- tion down to 10%-15%. > Exotic species have to be removed. This must be done as specified under Area of Envi- ronment Instruction IA/02.02: Managing fauna in ornamental fountains. > These exotic species have to be removed from ponds as soon as possible. Grey heron (Ardea cinerea). Laberint d’Horta’s wash house Monestir de Pedralbes’ pond with goldfish inside 180 181 CONSERVATION INITIATIVES Ensuring a balance of fauna in the ecosystem to preserve habitats and biodiversity Female wild duck and ducklings in the Palau Reial’s lake. Cat by the Tres Pins Plant Nursery’s pond Photo: Xavier Ferrer Description/application > Special care has to be taken with cat col- Where ducks upset the balance of the system, onies near to naturalised ponds to prevent it is advisable to capture them and transfer Yellow-legged gulls (Larus michahellis) have been seen preying on adult Iberian waterfrogs (Pelophylax them from preying on adult amphibians. In them to agreed areas. perezi) in the Jardins de Mossèn Cinto Verdaguer’s ponds. fact, predation by domestic cats is one of the main threats to the urban biodiversity, not just Where there are game species involved, such of amphibians, but also and especially of rep- as wild ducks (Anas platyrhynchos), authorisa- tiles, birds and small mammals. tion for capturing them will have to be request- ed from the Territorial Services at the Catalan It is therefore advisable to move such cat colo- Ministry of Agriculture, Livestock, Fishing and nies to other locations and, where that cannot Food at the Generalitat of Catalonia. be done, the colony’s feeding points should be kept as far as possible from the pond. > Native species can be found in naturalised urban ponds that are not from these environ- > Special attention should also be paid to ments, such as Spanish pond turtles (Maure- the presence of ducks in naturalised ponds. mys leprosa), European pond terrapins (Emys They adversely affect amphibian populations orbicularis) and even various species of fish. when they feed on algae that very often con- They are there as a result of having been re-in- tain hidden eggs or tadpoles, above all dur- troduced or abandoned and not by natural ing the amphibians’ breeding season (April colonisation. In such cases these animals will to July). They also affect the quality of the be transported to the Catalan Amphibian and aquatic plants by feeding directly on them or Reptile Recovery Centre (CRARC). using them as resting platforms. Finally, they adversely affect the quality of the water given Male wild duck in the Palau Reial’s lake. Photo: Xavier Ferrer that they soil it. The presence of ducks is also associated with the entry of organic matter (bread and food given by visitors) which cause serious imbalances in the ecosystem. 182 183 CONSERVATION INITIATIVES Not applying phytosanitary or chemical products to preserve the ecosystems’ natural processes Pontederia cordata Water lily (Nymphaea sp.) Description/application Phytosanitary or chemical products must not be used for controlling algae populations or when pests appear in aquatic plants. Water chlorination must also be avoided. To do so would mean altering the physical and chem- ical properties of the water and would there- by kill the tadpoles and aquatic invertebrates found in the pond. Iberian waterfrog (Pelophylax perezi) 184 185 CONSERVATION INITIATIVES Boosting invertebrate fauna in ponds to control mosquito-related problems Iberian bluetail (Ischnura graellsii) Dragonfly larva > On the other hand, water bugs, also known as backswimmers, dragonfly larvae and Ibe- rian bluetails and three amphibian species Jardins de Mossèn Cinto Verdaguer (common midwife toads in particular) prey di- rectly on mosquito larvae. Furthermore, a large number of aquatic insects that leave the water Description/application in their adult stage and fly around the pond area attract numerous insectivorous birds and A properly constituted, fully biologically performing pond contains a whole se- bats, which feed on adult mosquitoes. It is not ries of invertebrate and vertebrate fauna that keep the water system’s mosquito true, then, that the only way to keep mosqui- larvae under control and therefore considerably reduce the presence of winged toes at bay in a pond is by introducing fish. adults in the pond’s vicinity. > Tiger mosquitoes (Aedes albopictus) do not Common midwife toad (Alytes obstetricans) tadpole This beneficial action is due to the presence of a whole series of species of in- use large sheets of water as egg-laying habi- vertebrates which, like mosquito larvae, are detritivores (feed on organic matter) tats, but show a preference instead for scup- and which therefore exploit the same resource, so reducing the availability of pers, irrigation boxes and other points that food at the mosquito larvae’s disposal. Tadpoles, aquatic snails, water fleas and accumulate standing water, such as irrigation mayfly larvae, among other species, are detritivores that compete with mosquito plates and tank lids. In any case, being active larvae. during the day and low flying, insectivorous birds, dragonflies and Iberian bluetails make up their only predators. 186 187 There is a need, then, to boost their presence by offering a useful plant structure around the pond that enables insectivorous birds to find protection and nesting substrates; and, on the other hand, egg-laying substrates ought to be strengthened for dragonflies and Iberian blue- tails, using aquatic plants. > If mosquito larvae are to be kept away from ponds, it would be useful for the latter to have a water fountain whose jet of water creates movement over the sheet of water’s surface layer. This will break the water’s surface ten- sion and prevent mosquitoes from using the pond as an egg-laying substrate, given the water’s constant movement. It is important, however, for the movement of the water to ex- tend to every nook and cranny of the pond and thereby avoid creating stagnant water areas Sympetrum fonscolombii. Photo: Guillem Pascual capable of being used by mosquitoes. In this regard, fountains which give off rain-like jets of water will ensure a continuous trickle over the entire surface of the pond and prove to be truly effective. Naturalisation of the Can Cadena’s irrigation pool Water flea (Daphnea sp.) Common stonewort (Chara vulgaris) forms meadows that provide shelter for many invertebrates Movement of water that extends over the surface Tiger mosquito (Aedes albopictus) breeding space. Accumulations of stagnant water must be avoided 188 189 CONSERVATION INITIATIVES CONSERVATION INITIATIVES Naturalising ponds to maintain the water’s quality Surface re-circulation of water in naturalised ponds to maintain the water column’s stratification Great pond snail (Lymnaea stagnalis) Description/application The presence of zooplankton in a pond keeps its water transparent, as its direct filter-feed- ing reduces the aquatic system’s bacterial Tres Pins Plant Nursery’s pond load and phytoplankton. Water fleas (Daphnia sp.) are typical of such zooplankton and prove Description/application very useful in the management of naturalised ponds, as their filter action helps to maintain If a pond is to be kept clean and transparent it > It is therefore useful to promote a surface notable levels of transparency. is important for the concentration of the nu- re-circulation in such naturalised ponds which trients dissolved in the water to be rather low, maintains the water’s stratification while en- This transparency parameter has become to prevent population explosions among the abling the exchange of gases and preventing a key factor in our urban context, one that Water flea (Daphnea sp.) algae. This can be achieved to a large extent the presence of stagnant water. should at least be taken into account, as it is by ensuring the water column maintains its often gives rise to complaints from the public. stratification and that the nutrients are con- > Where the naturalised ponds or ornamen- On the other hand, the presence of detritivore fined to the pond’s sediment and beyond the tal fountains are provided with re-circulation fauna (pond snails etc.,) helps to speed up the algae’s range (they need light for photosynthe- systems, their pumps must be sized accord- organic matter’s decomposition process by sising and therefore live on the surface). Any ing to their respective container capacities, avoiding problems of anoxia (lack of oxygen) water re-circulating and filtering system that to prevent internal re-circulating and, in any associated with the water’s increased murki- stirs up the bottom of the pond and causes case, the water propulsion from affecting the ness caused by the rise of the pond’s bacterial the water column’s homogenisation will lead bottom of the pond. load. to eutrophic conditions that will upset the pond’s natural balance. 190 191 IMPROVEMENT INITIATIVES IMPROVEMENT INITIATIVES Improving environments to increase a habitat’s biomass Pruning the environment’s vegetation in several and suitability stages to maintain the fauna’s shelter areas Plantation of genus Fritillaria bulbs. Jardins de Mossèn Cinto Verdaguer Description/application Tres Pins Plant Nursery > Shelter and feeding areas need to be made Description/application or preserved by putting up rockeries, walls or other elements such as piles of trunks, plant > Where there is a need for pruning the en- pots and tiles, and by planting rhizomatous vironment’s plants, this must be planned in species such as the African lily (Agapanthus several distinct stages so fauna can be of- africanus) and the bearded iris (Iris germànica), fered shelter at all times. This means preserv- which offer amphibians numerous possibilities ing non-intervention areas with a sufficient for hiding and resting. Shrubby plants that pro- mass of plants to ensure amphibians and oth- vide a certain amount of cover can also be used er groups of fauna can shelter there. When a for this purpose. pruned area has finally reached an important stage of development and therefore provides a > The environment’s litterfall needs to be suitable cover, the area used as a shelter up to maintained as much as possible. It offers a that point will then be pruned. source of organic matter that will end up de- composed as humus, so closing the cycle of Lily plantation around the Tres Pins Plant Nursery’s ponds mineral elements. It also enables the develop- ment of a whole community of invertebrates sharing this decomposition and constituting, in its own right, a food resource for amphibi- ans and other groups of fauna. 192 193 IMPROVEMENT INITIATIVES Encouraging useful flora and fauna as a means to Description/application preserving biodiversity > Care needs to be taken of the following species: • Common midwife toad (Alytes obstetricans almogavarii). A small nocturnal toad. Its tadpoles can be observed in ponds throughout the year. A protected species under Generalitat of Catalonia’s Legislative Decree 2/2008 on Animal Protection. • Mediterranean tree frog (Hyla meridionalis). A frog that lives in the pond’s sur- rounding vegetation and which is therefore very sensitive to changes to veg- etation (extreme pruning). Its tadpoles can only be observed during breeding season. A protected species under Generalitat of Catalonia’s Legislative Decree 2/2008 on Animal Protection. • Iberian waterfrog (Pelophylax perezi). A frog that lives in the pond throughout the year. Its tadpoles can be observed throughout the year. • Common stonewort (Chara sp). Native fresh-water green algae, typical of lentic and low-nutrient water milieus, belonging to the Characeae family. It plays a very useful ecological role. It grows rather slowly but in stable condi- tions it can displace filamentous algae. (See annexe 2: Useful fauna in Barcelona’s fountains and ponds). Mediterranean tree frog (Hyla meridionalis). Photo: Guillem Pascual Iberian waterfrog (Pelophylax perezi) Common midwife toad (Alytes obstetricans) carrying eggs. Photo: Guillem Pascual Muskgrass (Chara sp.) 194 195 IMPROVEMENT INITIATIVES Introducing aquatic plants to create biotopes for the > When aquatic plant pots or flower boxes have to be prepared, it is important not to use fauna organic fertilisers or at least reduce their use as much as possible. Excessive fertiliser can lead to eutrophy and encourage the develop- ment of filamentous algae. For the same rea- sons, compost and other topsoils must not be used either as plantation. Materials such as gravel and grit will have to be used for that purpose. > Aquatic plants should be divided between Parc del Laberint d’Horta’s pond January and February, if appropriate. > During its building process, a pond should have an allocated area for receiving sunshine at least part of the day so that its aquatic plants can photosynthesise. It is true, howev- er, that too much exposure to the sun leads to a rise in the water’s temperature and an accel- eration of all the biological processes taking place there, making it more difficult to man- age and maintain. Azolla filiculoides. Photo: Wikimedia > Some aquatic plant species were tradi- tionally used due to their purifying capacities. No account has been taken, however, of the Tres Pins Plant Nursery’s pond fact that some of these are exotic plants with Description/application a highly invasive behaviour that causes seri- ous damage to natural systems. It is therefore > Aquatic plants should be put in naturalised better not to use species such as Azolla filic- ponds. Besides their aesthetic value, these uloides, Elodea canariensis or water hyacinth plants play ecological roles of the first order (Eichhornia crassipes), all being exotic and in- and are of vital importance in achieving the vasive, but rather to use an extensive variety aquatic system’s natural balance: of the environment’s native species. (See an- nexe 1: Aquatic plants at the Tres Pins Plant Elodea canadensis. Photo: Wikimedia • They capture the water’s nutrients for their Nursery). metabolism, thereby depriving unicellular and filamentous algae of these nutrients. All these exotic species are listed in Spain’s • They oxygenate the water through their pho- catalogue of invasive exotic species because tosynthesising, by raising the concentra- of their invasive potential and because they tions of oxygen dissolved in the water. represent a threat to our local flora. • They create biotopes for the pond’s inverte- brates and amphibians. • The flowers of some aquatic plant species Bosc de Montjuïc School’s pond attract pollinating insects. Water hyacinth (Eichhornia crassipes). Originally from South America, it is frequently used for its tissue’s capacity to retain heavy metals. Photo: Wikimedia 196 197 IMPROVEMENT INITIATIVES IMPROVEMENT INITIATIVES Managing the fauna’s access to ponds so amphibians Managing the public’s access to ponds to find a can get out of them balance between public use and natural development Angel Fountain. Pedralbes monastery Jardins de Mossèn Cinto Verdaguer’s ponds Description/application Description/application > Natural or artificial access points to ponds > Passage ways need to be adapted so the have to be put up so the amphibians can use public can enjoy ponds in a way that is com- them and complete their biological cycle. patible with the habitat’s preservation (in These structures will also enable the animals ponds whose size, for example, makes this to leave ponds they have accidentally fallen possible). into. 198 199 IMPROVEMENT INITIATIVES Public information for raising awareness of the value of these habitats and encouraging people’s contact with nature Description/application > Signage should be put up which conveys the habitat’s values as well as the concept of naturalisation and the positive effects it en- tails. 200 201 ANNEXE 1 ANNEXE AQUATIC PLANTS AT THE TRES PINS PLANT NURSERY PENDULOUS SEDGE (Carex pendula) Description: Presents long, deep-green, ribbon-like leaves. It develops large tufts that are often over a meter high (60-150 cm). Blossoming in the spring, its flowers are MUSKGRASS (Chara sp.) grouped in spikes of great ornamental value which can be maintained in the plant up to October. These spikes, Description: this is a native green alga some 50 cm long ranging from 10 cm to 15 cm in length, grow erect but im- which is notable for its leaves which grow from nodes on its mediately start to bend as they develop. stem and present a very characteristic whorled arrange- ment. Strictly speaking, algae have no roots, stems or Distribution: Eurosiberian region. leaves but do have similar structures, known as rhyzoids, cauloids and phylloids respectively. Habitat: riverine woodlands, river banks and pools. Semi-shaded. Distribution: multi-regional. Planting: in the spring, at a depth of between 0 cm and 10 cm under the surface of the water. Resist- Habitat: Stagnant, calcareous freshwater. ant to temperatures down to -20 ºC. Easy to plant and grows fast. It is not invasive. Planting: care should be taken to avoid removing all the Ecological value: Capturing nutrients (including heavy metals) and it is therefore recommended pond’s sedimentary materials, to enable the algae to take root. for water-purifying treatments. Presents a negative allelopathy, in inhibiting the growth of algae by exuding chemical substances through its roots. Creates biotopes for amphibians and invertebrates. Ecological value: it grows in clear water that is poor in nutrients (oligotrophic) and is therefore as- sociated with good-quality water. It is accordingly a bio-indicator species. It forms extensive under- water carpets that shelter numerous organisms, all necessary for balancing the aquatic ecosystem. It also contributes to the water’s purification, as it has an outstanding capacity for capturing nutri- ents, keeping the water transparent and even limiting the presence of mosquitoes in the pond, given that it releases larvicidal substances. SIMPLESTEM BUR-REED (Sparganium erectum) Description: Presents long and ribbon-like leaves that can reach a height of 100-150 cm. Blossoms between June and August. White and perfumed flowers. Its fruit is formed in glomerules. Distribution: multi-regional. Habitat: slow-water and shallow pools. Sunny or semi-shaded exposure. Planting: at a depth of between 20cm and 60 cm under the sur- face of the water. Resistant to severe frost. Invasive. Suitable for planting in sediments. Ecological value: Uncontaminated-water indicator Capturing nutrients. Creates biotopes for am- phibians and invertebrates. 202 203 HARD RUSH (Juncus inflexus) YELLOW IRIS (Iris pseudacorus) Description: a perennial plant with cylindrical stems that can Description: presents ribbon-like whitish-green leaves which reach a height of 40-120 cm. Blossoms between May and August. reach heights of between 50 cm and 120 cm. Blossoms between May and July. Abundant and strikingly yellow flowers. Distribution: multi-regional. Distribution: multi-regional. Habitat: bulrushes and humid areas with slightly acidic water. Lives in both shaded and sunny environments. Habitat: bulrushes, marshes and shores. Sunny exposure though it also accepts semi-shaded exposure. Planting: at a depth of between 2 cm and 10 cm under the sur- face of the water. It is advisable to plant it in high densities for Planting: at a depth of between 4 cm and 10 cm under the surface greater aesthetic value and a shaded area. It tolerates low tem- of the water. It reproduces vegetatively through its rhizomes. It peratures. It is invasive. It can be planted in sediments and in is a fast grower. It resists severe frosts. It is not invasive. It is suitable for planting in sediments or gardens. aquatic gardens. Ecological value: Water purifying by capturing nutrients. Creates biotopes for amphibians and in- Ecological value: Capturing nutrients. It is used for purifying water as it absorbs heavy metals. It can vertebrates. live in water with have concentrations of nutrients (eutrophic). Creates biotopes for amphibians and invertebrates. Its flowers attract bees. GARDEN LOOSESTRIFE (Lysimachia vulgaris) YELLOW WATER-LILY (Nuphar lutea) Description: this is a perennial plant that presents ramified Description: floating aquatic, perennial plant, with rhizomatous stems that are quadrangular in section. Its leaves are sessile roots and flat, oval leaves, though smaller and pricklier than and large. It reaches heights of between 50 cm and 150 cm. It those of European white water-lilies. The incisures of its leaves blooms between June and August and its flowers are grouped are less deep than they are in white water-lilies. It blossoms from into yellow inflorescences. June to September. Its flowers are yellow and 6 cm in diameter. Distribution: Eurosiberian region. Distribution: Eurasia. Habitat: reedbeds and grasslands on flooded or very humid soil. Habitat: Lakes and fresh-water ponds. Lives in both sunny and Sunny exposure though it also accepts semi-shaded exposure. semi-shaded areas. Planting: at a depth of between 0 cm and 6 cm under the surface Planting: in spring, to a depth of between 60 cm and 100 cm. Surface cover. It is advisable to plant of the water. It resists severe frost. It is not invasive. It can be it in spacious containers and periodically divide it. It can also reproduce from seeds. It tolerates planted in sediments and in gardens. temperatures down to -1 ºC. Ecological value: Capturing nutrients. Creates biotopes for amphibians and invertebrates. Its flow- Ecological value: It is not affected by water-lily aphids. It is a native water-lily. Creates biotopes for ers attract bees and butterflies. amphibians and invertebrates. Its flowers attract insects. 204 205 WHITE WATER-LILY (Nymphaea alba) PICKEREL WEED (Pontaderia cordata) Description: floating aquatic, perennial plant, with rhizomatous Description: perennial plant with shiny dark-green, narrow, lan- roots that present circular floating leaves that are dark green ceolate leaves. It reaches heights of between 60 cm and 130 cm. above and reddish underneath, between 10cm and 30 cm in di- It blossoms from June to September. Its flowers are grouped in ameter, with a deep, narrow incisure. It reaches heights of be- lilac-blue spikes. tween 5 cm and 10 cm. It blossoms from July to September. Very large, white, fragrant, floating pedunculated flowers, between Distribution: multi-regional. 10 cm and 20 cm. Habitat: ponds and lakes, in full sunshine. Distribution: multi-regional. Planting: at a depth of between 15 cm and 30 cm under the sur- Habitat: ponds and calm water. Prefers sunny environments, al- face of the water. Resistant to severe hard rime. It is not invasive. though accepts semi-shaded environments too. It is a fast grower. It is generally planted in plant pots. Planting: at a depth of between 50 cm and 120 cm under the surface of the water. Surface cover. Ecological value: Capturing nutrients. Creates biotopes for am- Does not tolerate temperatures below 5 ºC. Its bulbs divide in the autumn. It is suitable to plant both phibians. It is excellent for attracting and breeding dragonflies. Its flowers attract butterflies, bees in sediments and in aquatic gardens. and other invertebrates. Ecological value: Capturing nutrients. Creates biotopes for amphibians and invertebrates. The shading it creates limits the appearance of algae. Its flowers attract bees. FEN PONDWEED (Potamogeton coloratus) Description: Perennial, rhizomatous plant with floating, oval and UMBRELLA SEDGE (Cyperus alternifolius) reddy-green leaves, between 5 cm and 10 cm long. It reaches heights of between 10 cm and 50 cm. It blossoms from August Description: perennial plant that normally reaches heights of to October. between 40 cm and 120 cm. It has umbrella-shaped leaves at the end of its stems. It blossoms from May to September. Its yel- Distribution: multi-regional. lowish-white flowers are of little visual interest and are grouped in bunches. Habitat: slow-running, shallow small pools and brooks. Prefers water that is rich in calcium but poor in nutrients. Moderate sun- Distribution: Introduced. Originally from Madagascar. shine. Habitat: nearby river banks and water courses. Sunny or Planting: at a depth of between 20 cm and 60 cm under the sur- semi-shaded exposure. face of the water. Planting: at a depth of between 0 cm and 10 cm under the sur- Ecological value: Creates biotopes for amphibians and inverte- face of the water. It does not tolerate temperatures below 5 ºC. brates. It can be pruned every two years, at the end of winter. It is not invasive. It associates well with water-lilies and pickerel weeds. It is suitable to plant both in sediments and in aquatic gardens. Ecological value: Capturing nutrients. Creates biotopes for amphibians and invertebrates. 206 207 PURPLE LOOSESTRIFE (Lythrum salicaria) INDIAN LOTUS (Nelumbo nucifera) Description: perennial semi-aquatic plant with dark-green lan- Description: aquatic rhizomatous plant with large, round bluey- ceolate leaves. It reaches heights of between 60 cm and 120 cm. green leaves. It reaches heights of between 60 cm and 90 cm. It It blossoms from May to September. Its flowers are grouped in blossoms from June to August. It has large, generally white or purple clusters. pink flowers. Its fruit, which is shaped like an inverted cone, is of aesthetic value. Distribution: multi-regional. Habitat: exposure to moderate sunshine. Habitat: grasslands on humid soil watered by rivers and brooks. Exposure to moderate sunshine. Planting: needs a depth of at least 60 cm to grow. Planting in the spring. Reproduction by rhizomes in the spring-autumn and Planting: at a depth of between 0 cm and 10 cm under the surface by seeds. If its seeds are to be sown they need to be scarified of the water. Reproduces by seeds or plant division in the spring. with sandpaper and soaked in water. They will germinate within It resists severe frosts. It is not invasive. It is suitable to plant both a week and can be transplanted in large flower pots that their in sediments and in aquatic gardens. roots can grow in. It is advisable to remove dry leaves to prevent an excess of organic material from building up in the pond. It Ecological value: Its flowers attract bees and butterflies. does not tolerate low temperatures and suffers from problems below 5 ºC. Curiosities: Lythrum comes from the Greek lythron, which means blood. This refers to the colour of the flowers and to the antihemorrhagic effects that some of this genus’ species present. Hence its Ecological value: Capturing nutrients. Creates biotopes for am- other names in Catalonia, “estroncasang” (blood-stemming). And, because of its astringent proper- phibians and invertebrates. Its large leaves provide shade and ties, it is also known as “estroncaculs” or “herba de les cagarrines” (anti-laxative herb). therefore limit the growth of algae. Curiosities: it is the national flower of India. It symbolises purity, beauty, majesty, fertility, abundance, wealth, wisdom and seren- ity. It has been the symbol of good fortune in Indian culture since POWDERY THALIA (Thalia dealbata) antiquity. Description: this is a perennial plant with oval leaves held up by long peduncles. It blossoms from June to August. Its flowers are violet and grouped together in spikes. Distribution: multi-regional. Habitat: it grows in humid or shallow-water soil in full sunshine. Planting: at a depth of between 10 cm and 60 cm under the sur- face of the water. It reproduces by dividing its tubers in the spring. It resists severe frosts. It is not invasive. Suitable for planting both in sediments and in aquatic gardens. Indian lotus (Nelumbo nucífera) flower Ecological value: Capturing nutrients. Creates biotopes for am- and fruits phibians and invertebrates. Its flowers attract bees. 208 209 ANNEXE 2 USEFUL FAUNA IN BARCELONA’S WATER SNAILS (Physella acuta, Lymnaea stagnalis, Radix peregra, Ancyllus FOUNTAINS AND PONDS sp., etc.) Ecology: these species of aquatic snails feed off detritus and therefore play a very important role in processing the organic INVERTEBRATES matter (litterfall, small branches and food leftovers) of ponds. An excess of organic matter can cause an outbreak of anaerobic organisms which, in some cases, generate foul odours and toxins WATER FLEA (Daphnea sp.) that harm the pond’s biote. Such excesses of organic matter also make the water murky as a result of its increased bacterial load. Description: water fleas are small filter-feeding crustaceans that be- It is important, then, to ensure populations of aquatic snails are long to the Daphniidae family. They measure between 1 mm and 3 mm Photo: Guillem Pascual well represented and conserved. in length and are therefore visible to the human eye. Reproduction: they breed from spring to the end of summer. They normally lay their eggs among Ecology: they live in fresh water ponds, pools and lakes. They are aquatic plants or under their leaves. popularly known as water fleas because of the way they move. They have a pair of antennas they use for flagellating, as a means of moving Note: not all species of aquatic snails are detritivore; some feed on plant material (algae and aquat- around through water columns. Water fleas have a lifespan of around ic plant leaves). two weeks. Reproduction: they reproduce through parthenogenesis and in that Photo: Guillem Pascual respect they are very prolific animals. In optimal conditions a female can give birth to 10,000 million eggs in a period of 60 days. Its eggs can travel on the feathers or feet of aquatic birds, such as ducks, and move to another pond. MIDGES (Chironomus sp.) Feeding: they are filter-feeding animals that live off single-cell algae, bacteria and microscopic or- ganic remains. Its filtering action enables it to keep the pond’s algae populations in check, thereby Description: known as “mosquits d’eixam” (swarm mosquitoes) increasing the water’s transparency. in Catalan due to the fact that, as adults, these midges form huge swarms around water. Their larvae vary in colour depend- ing on the species; some, given their red-coloured body, are also popularly know as “mosquits vermells” (red mosquitoes). This Photo: Guillem Pascual colour is due to the presence of a respiratory pigment, haemo- globin, which enables them to capture oxygen in the water where it is found in low concentrations. Ecology: larvae live in the sediment of the pond and feed off the remains of organic matter. Chirono- mids in water act as a bioindicator of its quality. Their presence is in response to low concentrations of oxygen normally associated with stagnant water with a high level of organic matter and therefore poor in quality. Unlike their common mosquito female counterparts, they do not bite, as they do not feed on blood; in fact, many of these species do not feed during their adult stage, which they reach for reproductive purposes. 210 211 MAYFLY (Cleon sp.) DRAGONFLIES AND DAMSELFLIES (Anax imperator, Sympetrum striolatum, Ischnura graellsii) Description: these are notable for their larvae with three very long tails at the end of their abdomen and gills at the side Description: damselflies are noted for their slim, elongated body of their abdomen which allow them to breathe under water. and well-separated eyes. By contrast, dragonflies have a stouter Adults also have two long tails and fins with very pronounced body and closely set eyes. Nevertheless, the distinctive feature nerves that fold backwards. that best allows damselflies to be distinguished from dragonflies is that the former fold their wings backwards when resting while Ecology: their name refers to their short lifespan as winged the latter keep theirs open. Photo: Guillem Pascual adults (a single day). In fact, when adults, they have no mouth and therefore cannot feed, using their short life for reproduc- Anax imperator. Photo: Guillem Pascual Ecology: they have a short lifespan (several weeks) which they tion. Their larvae are aquatic and move around the bottom and walls of ponds, feeding on organic make the most of to reproduce. Females lay their eggs in the wa- remains. They are important in the decomposition cycle of organic matter. ter which the larvae hatch from to feed on aquatic invertebrates, small tadpoles and fry, all of which they capture using a strong, foldable mandible. Note here the large predatory capacity of these larvae. After numerous moults, the larvae become nymphs which finally emerge from the water, climbing up the stem of an aquatic plant and breaking their exuviae (exoskeleton) to enter Dragonfly Crocothemis erythraea. An- their adult stage. A full cycle can last up to two years, depending other regular visitor to ponds. Photo: Guil- lem Pascual on the species. Adult dragonflies and damselflies feed on a large BACKSWIMMERS (Notonecta maculata, etc.) variety of flying insects, such as mosquitoes. Description: these swim on their backs on the surface of the water, helped along by their hind legs, which are longer than their others and are used as oars. Their middle legs are used for grabbing hold of underwater vegetation and, together with their forelegs, for capturing prey. They have functional wings be- neath their protective wings which enable them to fly and move to new ponds when their present ones dry up. Ecology: backswimmers live in ponds, pools and anywhere that ac- cumulates stagnant water. They have a stinging-sucking mouth piece they use for feeding on small invertebrates, such as mosquito and fly larvae as well as vertebrates such as small tadpoles and fry. Dragonfly exoskeleton Photo: Guillem Pascual Their predatory condition gives them an important role in the food chain, as they regulate both invertebrate and vertebrate populations and therefore contribute towards the pond’s equilibrium. 212 213 AMPHIBIANS MEDITERRANEAN TREE FROG (Hyla meridionalis) Description: this is a small, smooth-skinned frog, some 5 cm COMMON MIDWIFE TOAD (Alytes obstetricans) long, notable for its bright green colour and a black stripe across its face. In fact, it is this stripe which allows it to be told apart Description: this is a small toad, some 5 cm long, brown in colour from the tree frog from the same genus which is also present on and with granulated skin and small tubercles. It has vertical pu- the Iberian peninsula: the European tree frog (Hyla arborea); in pils and golden irises with black spots and rounded muzzle with the latter’s case, the black stripe runs along its sides to reach its two visible nasal orifices. Tadpoles from this species are large back extremities. It has a whitish ventral area and horizontal pu- and robust, with a rounded muzzle too, and usually move around Photo: Guillem Pascual pils. Tadpoles from this species are small and delicate. It is not- the bottom of ponds. ed for its disproportionately large and prominent eyes. It moves along the bottom through the water column. Ecology: nocturnal, lives among litterfall, rocks and rhizomatous plants near to ponds. Ecology: adult tree frogs are normally found in dense vegetation Unlike other amphibian species, it lays its eggs outside the wa- nearby the ponds they use for sunbathing during the spring and ter, so once the female has finished laying its eggs, a male will summer. It is a climber by nature. During the winter, however, it then fertilise them and wrap them around its extremities, trans- usually shelters between litterfall and trunks, where it remains porting them for roughly three weeks, which is the time neces- inactive. sary for tadpoles to hatch. Males then look for water points such Photo: Guillem Pascual Males are territorial and therefore compete with one another to as ponds, pools, fountains and brooks for releasing the tadpoles find a place in the pond and attract females through their croak- so they can continue developing. Males can carry eggs from sev- ing. Common midwife toad. Note its vertical eral females and each laying episode can contain between 20 This species only uses ponds for breeding. pupils, golden irises and nasal orifices and 60 eggs. Reproduction: it breeds from the spring to the end of the sum- Reproduction: males attract females at the start of spring through a very characteristic call rem- mer. After mating, females lay their eggs in the pond’s under wa- iniscent of the call of a small summer insectivore: the Eurasian scops owl (Otus scops). They can ter vegetation. It is at this point that the tadpoles complete their be heard croaking during humid spring nights. In any case, they present two breeding seasons, the metamorphosing, so that the first juvenile frogs can be seen out- most important being in the spring and the other in the autumn. That means tadpoles can be seen side the pond as from August. in ponds throughout the year, as some of those hatched in the autumn move into the water in the winter (metamorphosing tadpoles) thereby completing their metamorphosis in the following year. Feeding: adults feed on small invertebrates, such as mosquitoes, A pair of amplexus tree frogs . Note the small cockroaches, ants and flies. Tadpoles feed on algae and Feeding: adults feed on worms, spiders, snails, slugs and other invertebrates. Tadpoles, by contrast, difference in size: the larger female below and smaller male above. Photo: aquatic plants. are detritivores and feed off decomposing organic matter, although their diet also includes mosqui- Guillem Pascual to larvae. Location: in Barcelona they breed in the artificial pools in the Jar- dí d’Aclimatació de Montjuïc, the gardens of the Palau Reial, the Tres Pins Plant Nursery, the Jardins Location: Barcelona has historical populations in the ponds at the Tres Pins Plant Nursery, the Jar- de Mossèn Cinto Verdaguer and the Laberint d’Horta, to name a few places. dins del Laberint d’Horta, in the old Botanical Gardens, at the Teatre Grec and the Jardins de Laribal, among other places. 214 215 TADPOLE-IDENTIFICATION GUIDE IBERIAN WATERFROG (Pelophylax perezi) Description: this is a frog that comes in many varieties of colour COMMON MIDWIFE TOAD TADPOLE that can range from green to brown or grey with dark spots. It has Distinctive traits a whitish, spotted ventral part. It presents sexual dimorphism in its sizes: females can measure as long as 11 cm, whereas males Size Up to 90 mm are a bit smaller and are usually roughly 8 cm. Position of eyes Dorsal and closely set eyes It has horizontal pupils and golden irises. Its tadpoles are large In the middle of the stomach (closer to the mouth and robust with a pricklier muzzle than those of common mid- Position of spiracle than the anus) wife toads and without visible nasal orifices. It mainly moves around the bottom and walls of ponds. Position of anus In the ventral area in the central position Tail With dark spots Ecology: Iberian waterfrogs live in water throughout the year, though they can make sporadic incur- Muzzle Rounded sions onto land in search of food and new ponds. It is the most aquatic of the three species, to the point where it normally spends the winter in the pond buried in the sediment. Behaviour It moves around the bottom and walls of ponds. Reproduction: it breeds late, as it starts at the end of the spring and continues up to the end of the summer. It lays its eggs in aquatic vegetation. Its tadpoles can spend the winter in ponds, just like TREE FROG TADPOLE common midwife toads and can therefore be found in ponds throughout the year. Distinctive traits Size Up to 40 mm Feeding: it feeds on a large variety of both land and aquatic invertebrates as well as small verte- brates, including metamorphosing tadpoles from the same or other species. Its tadpoles feed on Position of eyes Prominent lateral eyes detritus and plant material. Position of spiracle In the middle of the stomach (closer to the mouth than the anus) Location: Barcelona has historical populations in the Jardins de Mossèn Cinto Verdaguer, the Tres Position of anus In the ventral area to the right and close to the head Pins Plant Nursery, Turó Park and the Laberint d’Horta, among other places. Presents a caudal ridge that appears behind the eye, Tail very high and convex above and below and which ends in a sharp point Muzzle Rounded Behaviour It moves along the pond’s water column IBERIAN WATERFROG TADPOLE Distinctive traits Size Up to 110 mm Position of eyes Dorsal and separated eyes Position of spiracle In the lateral left area of the head Position of anus In the ventral area on the right Presents a caudal ridge with dark and large spots. A Tail longitudinal central dark line can be observed along its tail Muzzle Prickly Behaviour It moves along the pond’s water column Source: Catalan tadpole identification guide. www.gno.cat/media/ambits/guiacapgrossos2.pdf 216 217 ANNEXE 3 LIST OF GARDENS WITH NATURALISED PONDS IN BARCELONA AND THEIR ASSOCIATED FAUNA GARDEN ASSOCIATED FAUNA Iberian waterfrog, tree frog, dragonflies and other Jardins de Mossèn Cinto Verdaguer aquatic invertebrates Jardí d’Aclimatació Tree frog, Iberian waterfrog and aquatic invertebrates Jardins del Teatre Grec Common midwife toad and aquatic invertebrates Common midwife toad, tree frog and aquatic Jardins de Laribal invertebrates, including planarians (Schmidtea mediterranea) Iberian waterfrog, common midwife toad and other Turó Park aquatic invertebrates Tree frog, Iberian waterfrog, common midwife toad Jardins del Palau de Pedralbes and aquatic invertebrates Common midwife toad, tree frog and aquatic Jardins de la Tamarita invertebrates Common midwife toad, tree frog, Iberian waterfrog, Jardins del Laberint d’Horta Spanish toothcarp, viperine water snakes and aquatic invertebrates Common midwife toad, Iberian waterfrog and aquatic Tres Pins Plant Nursery invertebrates Can Cadena pond Iberian waterfrog and aquatic invertebrates 218 219 INDEX INTRODUCTION 222 CONSERVATION INITIATIVES Conserving cliffs 224 Managing plants on walls 225 Preserving cavities/gaps in walls 226 IMPROVEMENT INITIATIVES Preparing inventories and monitoring walls 228 B oosting the presence of plants on walls of little use to fauna 230 Adapting the sizes of holes in walls 232 Adapting holes to several wall heights 234 C arrying out redevelopment work on buildings during appropriate periods 235 Promoting installations of artificial nests in buildings 236 Preparing management plans for cliffs 238 ANNEXE 1 Stone walls 240 ANNEXE 2 Fauna in buildings 250 221 CLIFFS, WALLS AND PARTY WALLS INTRODUCTION Cliffs are rocky formations with a steep slope – sometimes completely verti- Walls cal – that are found not just at points of contact between land and sea but on mountains. These formations are interesting for their geological and landscape Stone and other walls, as artificial formations, can host several plant species aspects and for the presence of rupiculous flora and fauna (living among rocks). and help to encourage the presence of invertebrates, reptiles, birds and small Cliffs are scarce along the Catalan coastal depression, although Barcelona itself mammals. There are a very large number of stone walls and some, especially in has three notable cliffs: the Morrot cliff, on the south-east-facing slope of Mont- parks and more recent sites, take the form of gabion walls, in other words, con- juïc and next to the commercial port and, more inland, the Parc de la Creueta del tainers of stones held together with a wire mesh. Given the history and layout of Coll cliff and the Tres Turons cliff. the city, hundreds of smooth walls (without holes or cracks) can also be found. The life forms associated with stone walls depends on the environment in which Rock-quarrying activities over many centuries ended up forming rupiculous hab- it is situated, orientation, geological substrate and height. Animals find shelter in itats playing similar roles to natural cliffs and which today enrich the city’s or- them and a place for rearing, feeding and hibernating. Cracks and holes need to nithological biodiversity with species scarcely found in cities, such as blue rock be preserved if biodiversity is to be maintained, a simpler goal in stone walls than thrushes, owls, kestrels and peregrine falcons (Morrot). The latter space presents in smooth ones. In the latter case, fauna can take advantage of elements such as a large ornithological variety that is complemented with reptiles and small mam- ventilation holes for the same purpose. mals. It is worth noting that Morrot’s kestrels formed a nesting colony, despite the fact the species does not usually exhibit such gregarious behaviour. Party walls also offer opportunities for biodiversity that can be used for example, for putting up integrated artificial nests or plants. In fact, some of them are either It is therefore a place with great potential as a point of attraction for bird watch- completely or partially covered with plants that encourage the presence of fau- ers. na. A distinction should be made, however, between party walls that may be tem- porary, owing to the construction of new buildings, and those that have become permanent. In any case, the initiatives that can be embarked on in these spaces are full of nuances that have to be assessed on a case-by-case basis. Wall inventories and cliff-management plans are two major tasks that should make a big contribution to the goals described. 222 223 CONSERVATION INITIATIVES CONSERVATION INITIATIVES Conserving cliffs to protect against their deterioration Managing plants on walls to boost their biodiversity Parc de les Aigües’ gabion walls Description/application Montjuïc’s cliffs The various possibilities for action in the veg- > Where plants have to be removed for or- Description/application etation’s maintenance need to be studied ac- namental purposes, cleaning should be done cording to each wall’s features and associated preferably during the winter period, there- It is important to appreciate these natural biodiversity. by avoiding, if further action is required, the sites, as they constitute a rare rupiculous birds’ nesting period. habitat in an urban context and play a very Several options are being considered: notable ecological role. They host a series of A preliminary assessment must therefore be > Not “vegetating” stone or other walls where plant and animal communities typical of these made to ensure maintenance work is not car- they already exhibit biodiversity. Established environments which need to be conserved and ried out to the detriment of biodiversity. house sparrow (Passer domesticus) colonies promoted as points of special interest for en- or great tit (Parus major) nests, for example, riching biodiversity. are grounds for ruling out any landscaping and for preventing undesirable predators, such as > Periodic cleaning has to be carried out to rats, from gaining access. prevent the build-up of rubbish that may harm the natural heritage or cause fires. > If the wall already has climbing plants and is used for nesting or sheltering birds, pruning work will have to be done (outside the birds’ nesting period) so these plants can be con- tained. Tres Pins Plant Nursery. Montjuïc 224 225 CONSERVATION INITIATIVES Preserving cavities/gaps in walls to encourage several species to find shelter and nesting places there Tres Pins Plant Nursery House sparrow (Passer domesticus) nest Description/application Holes should not be obstructed or cracks filled in if these spaces are to allow the pres- ence of fauna. It is advisable, where possible, in the case of newly built stone walls, to use dry stone, as it offers great durability and en- vironmental benefits, such as halting the soil’s erosive processes and creating habitats for numerous animal and plant species. (See an- nexe 1: Stone walls). In any case, the use of cement and concrete should be avoided for covering over cracks or holes or at least to Parc de Joan Raventós consciously leave them without filling them in. 226 227 IMPROVEMENT INITIATIVES Preparing inventories and monitoring walls for designing biodiversity-promoting initiatives Mas Ravetllat’s stone walls Stone walls. Pedralbes’ allotments Description/application Key factors must be taken into account, such as orientation, geological substrate or height where the holes etc., are located, such as de- gree of sun exposure, which is very important for reptiles. The inventory should also include the species most frequently found in the area that can use the space studied as a habitat. It is therefore a question of knowing the features of the city’s walls so pro-diversity initiatives can be designed and monitored. Such work is intended to help establish the general guide- lines the specific initiatives will fall under and whose results will subsequently be checked. Passeig de Turull 228 229 IMPROVEMENT INITIATIVES Boosting the presence of plants on walls Climbing plant species which interact with lo- cal fauna need to be selected. Examples: of little use to fauna to ensure a suitable degree of vegetation and promote biodiversity > Common ivy (Hedera helix) is a good choice as it develops a large density of foliage, so pro- viding nesting and sheltering places for spe- cies such as Eurasian blackcaps (Sylvia atri- capilla), white wagtails (Motacilla alba) and common blackbirds (Turdus merula). What is more, it blossoms in the autumn (which is beneficial for bees, wasps, hoverflies and but- terflies) and fruits in the winter, providing food for birds such as the above-mentioned black- caps, blackbirds, Sardinian warblers(Sylvia melanochepala), European robins (Erithacus rubecula) and black redstarts (Phoenicurus ochruros), during a time of the year when food resources are scarce. It also ensures a con- stant presence of insects and invertebrates, which are the basis of the food chain and therefore increase the complexity of the food relationships of the various groups of fauna. > Other native plants that are useful for Common ivy (Hedera helix) their fruit and/or flowers include: caper bush- es (Capparis spinosa), Minorca honeysuckle (Lonicera implexa), common hop (Humulus lu- pulus), Old man’s beard (Clematis vitalba), fra- Wall vegetated with lesser bougainvillea (Bougainvillea glabra) Parc del Centre del grant virgin’s bower (Clematis flammula), elm- Poble Nou leaf blackberry (Rubus ulmifolius), dog-rose Description/application (Rosa canina), evergreen rose (Rosa semper- virens), common grape vine (vitis vinifera) and Walls without holes or cracks should be veg- rough bindweed (Smilax aspera). etated, to make them more attractive to fau- na, by offering them opportunities for feeding, > It is also advisable to use alien climbing sheltering and nesting. In some cases it would plant species such as Chinese wisteria (Wis- be advisable not to cover the entire walls but teria sinensis), the Australian “native” wiste- to leave areas exposed to enable the presence ria (Hardenbergia comptoniana), Chinese star Rough bindweed (Smilax aspera) of desired predators, such as common wall jessamine (Trachelospermum jasminoide) and geckos (Tarentola mauritanica), whose hunt- the passionflower (Passiflora caerulea), all of ing territories lie in these plant-free areas. which have flowers that attract pollinating in- sects. Common wall gecko (Tarentola mauritanica) with regenerated tail 230 231 IMPROVEMENT INITIATIVES Adapting the sizes of holes in walls to influence the > Rock pigeon (Columba livia): pigeons can enter round holes with diameters of at least 8 presence of certain species cm (and rectangular holes measuring 5 cm x 14 cm). If we bear in mind the large population of pigeons found in Barcelona (around 85,000, according to the Barcelona Public Health Agency data from 2015), it would be useful to keep down the number of holes of this size to provide more options for rarer species. In this regard, we can opt to reduce sizes of en- try holes by putting metal railings over them and preventing their access. Restricting the number of rest and breeding places available to them using deterrent elements and limiting Rock pigeon (Columbia livia) the number of feeding spaces are other meas- ures that can be put in place, besides culling (where the population densities of this species reach levels posing a risk to public health). > Western jackdaws (Corvus monedula): are small ravens present in Barcelona which use holes and the chambers provided by buildings in the old quarter and Eixample to build their nests in. The main problem for their conserva- tion is that they use holes with similar sizes to pigeon holes. It must therefore be borne in mind that the option of covering up holes in places with existing populations can have House sparrow (Passer domesticus) negative effects on this species, whose num- bers are falling. Description/application Adapting holes for jackdaws. Fàbrica del Sol Hole sizes in buildings and environments that Biodiversity needs to be boosted by limiting jackdaws nest in can be reduced to 7 cm di- the presence of excessively abundant species ameters (or to 6 cm x 12 cm where the holes and offering opportunities for rarer species. are rectangular), to make it hard for pigeons to For this reason it is useful for holes and cracks access. to come in different sizes. Hole sizes deter- mine the type of fauna that can access them: Western jackdaw (Corvus monedula) 232 233 IMPROVEMENT INITIATIVES IMPROVEMENT INITIATIVES Adapting holes to several wall heights to promote the Carrying out redevelopment work on buildings diversity of species during appropriate periods to avoid interfering in animals’ biological cycles Redevelopment work on Carrer d’Astúries with adjustments to party-wall entrance holes for swifts. Photo: Sergi Garcia Description/application House sparrow (Passer domesticus) nesting colony The fauna that is present must be known be- be noted that authorisation is required from forehand, through an inspection of the space the Barcelona branch of the Catalan Ministry Description/application in question. of Agriculture, Livestock, Fishing and Food Once it is known, action can be planned for of the Generalitat of Catalonia, if protected > Holes need to be located at various heights what is reckoned to be the most appropriate species (swifts, swallows and bats) are to be to offer feeding, sheltering and rearing oppor- time. removed or prevented from accessing their tunities to several groups of fauna. Whereas nests. amphibians, reptiles and some micromam- > The period of action in buildings that have mals use holes on the lower parts of walls, to be redeveloped should be between Novem- > Two important periods need to be borne in other animals, such as birds, avoid holes near ber and March, as most species associated mind for bats (Chiroptera): the winter, during the ground owing to the easy access they pro- with buildings (swifts and swallows) migrate which bats group together in shelters that pro- vide predators with. For some species, then, in the autumn and return in the spring. If the vide them with more or less constant temper- hole heights are a limiting factor which has to nature of such work makes it impossible to atures; and the spring, during their breeding be borne in mind. So it is a good strategy for finish within this period, the entrance holes season in sunny, south-facing shelters. So any the wall to present holes at several heights to will have to be closed, using nets or canvas, work that affects the hibernating colonies will promote biodiversity. before the birds arrive, to prevent them from have to be carried out in the spring or summer; nesting in them and starting their breeding whereas any work that affects the breeding process (spring-summer). It should of course will have to be performed over the winter. 234 235 IMPROVEMENT INITIATIVES Promoting the installation of artificial nests in > Putting up artificial nests integrated into newly constructed buildings and revamped party walls and façades. buildings to encourage the presence of fauna (See annexe 2: Fauna in buildings.) Common house martin nests. Correus building. Photo: Sergi Garcia Roof tiles for swallow nesting Description/application Buildings provide support for urban biodiversity given that several species, at- tending to their biological needs, use them as escarpments or natural structures. Rural buildings offer places for breeding in holes and cracks. By contrast, newly constructed buildings are generally unsuitable for hosting fauna, for reasons of aesthetics and sustainability. Several types of action are evident then: > Ordinary and tiled roofs can have ventilation tiles that can be fitted into them when they are being revamped, with an opening hole that gives fauna access to the interior. > Closed-off rooms’ ventilation holes can be left open when façades or party walls are being redeveloped. Where the holes are large we can reduce their sizes to prevent pigeons from entering them. Common swift (Apus apus) nest on Carrer Pavia. Photo: Sergi Garcia 236 237 IMPROVEMENT INITIATIVES Preparing management plans for cliffs for preserving and boosting their biodiversity El Morrot de Montjuïc Caspian gull (Larus cachinnans) on Montjuïc’s cliff Description/application > Management plans will have to incorpo- > Management plans will also have to take Creueta del rate a series of general goals: account of each cliff’s specific characteristics Coll’s cliffs • Creating access-deterring elements in and values: certain parts of the cliffs to promote the conservation of fauna and flora and deal El Morrot de Montjuïc Creueta del Coll’s cliffs Turó de la Rovira with safety issues. • Mixing field plants and Mediterranean • These present a plant and fauna community • Geological, social and landscape interest. • Establishing and sign-posting routes. brushwoods with naturalised exotic species in an outstanding state of conservation in an • Two interesting biotopes: common thatching • Highlighting the natural values of sites and a large diversity of bird species with urban context. grass fields (Mediterranean dry fields) and with appropriate signage. kestrels and owls and unusual species in • Geological, social and landscape interest. rupicoline environments created by operat- • Avoiding accumulations of rubbish, to urban contexts such as the blue rock thrush • Existence of a mass of water that encourag- ing the quarry. prevent fires and the deterioration of the (Monticola solitarius). es the presence of birds and bats (chirop- • Situation of alignment with Parc Güell and space. • Geological interest: Montjuïc is listed in the tera). Parc del Guinardó (an axis that enables the Catalan catalogue of sites of geological in- fauna to disperse and move around). terest. • Landscape interest: views over the commer- cial port. 238 239 ANNEXE 1 ANNEXE STONE WALLS Insects and other invertebrates These are the group that shows the strongest relationship with stone walls, with a large number of invertebrates seeking shelter and breeding spaces in these structures. They are at the staple food that the other groups of fauna depend on and therefore occupy a key position in the food chain. They also play a vital role in controlling pests. Earthworms, centipedes, milipedes, scolopendromorpha, spi- ders, snails, cockroaches, grasshoppers are just a few of the invertebrates that can be found in association with stone walls. Dry stone walls. Les Gunyoles. Barcelona Province Stone walls have been used in the rural world by making the most of the material found from clearing stones from fields. Even so, the technique for building dry stone walls stopped being used, for mainly economic reasons, during the latter half of the 20th century. Note, however, the great cultural and landscape value dry stone walls have, seeing as they are part of our Mediterranean heritage and enjoy a series of ecological advantages that other types of walls do not offer: • They halt the soil’s erosion processes. • They play a very important thermal role, as they dampen the effects of temper- ature. Beetle (Blaps lusitanica) Wasp spider (Argiope bruennichi) • They keep cool during the summer’s high temperatures and absorb heat during the winter. • They stay humid inside. Such features make dry stone walls an ideal habitat for many species of fau- na and flora seeking shelter, breeding and nesting places, food and hibernation places. The wealth of an area’s fauna is connected to the diversity of the milieus that the environment offers and, in this regard, dry stone walls help to increase this biodiversity. 240 241 Amphibians Reptiles The use of stone walls by amphibians is directly linked to the presence of aquatic They use stone borders for sheltering, breeding and feeding as well as sunbath- milieus in their nearby environment. They use them as shelter and feeding spac- ing (they are poikilothermic animals, that is, they have no mechanism for reg- es, so they occupy a place half-way along the food chain. They are preyed on by ulating their body temperature and therefore need to sunbathe to stay active). snakes and birds - as well as cats, when it comes to urban contexts - while prey- Geckos and lizards are the best adapted to this ecological niche, as they find ide- ing themselves on small invertebrates. The main species in Barcelona that can al temperature and humidity conditions there. They occupy a halfway point along use stone walls are as follows: the food chain, as they are preyed on by snakes and small birds of prey, such as common kestrels, while preying themselves on insects. The following are the most frequently found species here: Common wall gecko (Tarentola mauritanica). Photo: Sergi Garcia Male Columbretes wall lizard (Podarcis liolepis) Common midwife toad (Alytes obstetricans) Mediterranean house gecko (Hemidactylus turcicus). Large psammodromus (Psammodromus algirus). Photo: Sergi Garcia Mediterranean Photo: Sergi Garcia tree frog (Hyla meridionalis). Photo: Guillem Pascual 242 243 Although rarer, given the urban context, snakes should not be forgotten either, Birds with stone walls providing them with spaces for resting and protection from predators, as well as feeding places for the high number of prey found in walls, Being vertical, walls make access difficult for predators and offer some security such as micromammals and small birds. Note that snakes are protected species when it comes to finding suitable nesting places. and may not be taken or disturbed. They are harmless species. Two species of snake found in the most wooded parts of the city are: Cats and rats are becoming their main threat in cities, as they feed not just di- rectly on adults but on eggs and baby birds. Some birds rear in the holes and cracks of walls and many others use them as a watch tower, so their value for this group of fauna is very notable. Although they do not always use stone walls as nesting substrates, it is hardly surprising to find the following species nesting in them: • House sparrow (Passer domesticus) • Eurasian blue tit (Cyanistes caeruleus) • Great tit (Parus major) • Black redstart (Phoenicurus ochruros) • European robin (Erithacus rubecula) • Little owl (Athene noctua) Montpellier snake (Malpolon monspessulanus). Photo: Guillem Pascual Black redstart. Photo: Wikimedia Eurasian blue tit. Photo: Wikimedia Ladder snake (Rhinechis scalaris). Photo: Guillem Pascual Little owl. Photo: Wikimedia 244 245 Mammals Lichens Where the wall’s environment presents a suit- Lichens are grouped under several categories, depending on the nature of the able level of plant development, such struc- substrate they colonise. One of them is lichens saxicola, which grows on rocks tures are frequently used by small mammals. and can be found associated with stone walls, where the levels of the environ- They provide spaces for storing food, shelter- ment’s pollution so permit. It is worth highlighting their role here as bio-indica- ing or breeding. Micromammals are natural tors. Some of the lichens we can find on rocks are: prey for snakes, birds of prey and other mam- mals such as foxes and genets and therefore • Xanthoria parietina play an important role in the food chain. Wild • Caloplaca flavocitrina cat colonies in the city are having an adverse Greater white-toothed shrew (Crocidura russula) • Verrucaria macrostoma affect on their populations. Likewise, insectiv- orous micromammals, such as shrews, prey on small insects and a whole range of inverte- brates, whereas rodent micromammals (mice) play an important ecological role in dissemi- nating seeds. The main species associated with walls are: Wood mouse (Apodemus sylvaticus) Steps at Laberint d’Horta Western Mediterranean mouse (Mus spretus) Black rat (Rattus rattus) Brown rat (Rattus norvegicus) Xanthoria parietina 246 247 Ferns and mosses Higher plants Dry stone walls situated in humid places often host mosses and small ferns. There are many species of small plants that are directly linked to the presence of Some fern species associated with walls are: stone walls. They notably include: • Southern maidenhair fern (Adiantum capillus-veneris) • Ivy-leaved toadflax (Cymbalaria muralis). This species introduces its fruit into • Rustyback (Ceterach officinarum) cracks in walls, so their seeds, when they germinate, will be in optimal conditions • Maidenhair spleenwort (Asplenium trichomanes) for colonising the stone wall within a few years. Southern maidenhair fern (Adiantum capillus-veneris) Caper bush (Capparis spinosa). Pedralbes monastery Mediterranean stonecrop (Sedum sediforme) Eastern pellitory-of-the-wall (Parietaria officinalis) Ivy-leaved toadflax (Cymbalaria muralis). 248 249 ANNEXE 2 FAUNA IN BUILDINGS BARN SWALLOWS (Hirundo rustica) Typical of rural milieus, though it is not rare to see them in the city in One of the measures for boosting urban biodiversity is putting up artificial nests places near aquatic environments or large parks. for species that use buildings for nesting. Everyone is familiar with swallows and swifts, insectivorous and migratory species of birds which, coming from the Af- Nest: They build their nest out of mud and small plant fibres, in the rican continent, reach our shores in the spring to breed. They can be easily spot- shape of a pot which they locate in sheltered places such as roofs, at- ted during the summer, especially during the start or end of the day, flying over tics, interior courtyards and warehouses. buildings in search of flying insects. They play a very important role in controlling insect populations. They embark on their return journeys to the African continent Nesting: they breed at the end of May, laying batches of four to six eggs during the summer or start of the autumn, seeking milder winter temperatures. which they incubate for fourteen days, after which their chicks hatch, becoming fledglings at the end of roughly one month. They can lay a second batch. They are a species protected by Catalan regional legis- lation, so their nests may not be destroyed without authorisation from Barn swallow’s artificial nest. Can Mestres. the Generalitat of Catalonia’s Fauna Protection Service. Photo: Eduard Durany Initiative: we can help this species by putting up sheltered artificial nests over two metres high, to prevent predators from gaining access. They prefer sheltered places although these have open entrances and exits. Nests need to be 1 m to 2 m apart and it is advisable to leave be- tween 6 cm and 8 cm between the nest and the ceiling. Barn swallow’s nest. Photo: Eduard Durany COMMON HOUSE MARTIN (Delichon urbicum) They mainly rear in building façades along the outskirts of the city, though invariably in places that are close to open spaces which they Alpine swifts (Tachymarptis melba) in flight. Photo: Oriol Alemany use as feeding places. Nest: they build their nests under balconies and eaves and normally Swallows group together in colonies. Unlike barn swallows, their nests are spher- Photo: Sergi Garcia ical and closed, and only present an entry and exit hole on one side at They have numerous problems finding muddy areas in the city and therefore the top of the nest. quality material for building their nests from. The buildings’ walls are often too smooth for their nests to cling to securely. Nesting: they start breeding at the end of May, laying batches of six eggs, and their chicks take less than a month to become fledglings. Creating bogs in open areas in parks and gardens and putting up artificial nests They can lay a second batch. They are also a protected species under in suitable places are helpful measure for swallows. There are two species of the Catalan regional legislation. swallow genus found in Barcelona: Initiative: we can help this species by putting artificial nests on eves and under balconies above a height of roughly 4 m. Common house martin nests 250 251 Common swift and Alpine swift Places with a sufficient height need to be looked for, if common and Alpine swift nests are to be put up. For Alpine swifts, the height would correspond to a build- These are two of the species we find in Barcelona and which use the city’s build- ing’s fifth floor and for common swifts to at least a second floor, so these species ings for establishing nesting places, normally situated in false ceilings, rain can easily retake flight. The length of their wings prevents them from taking off screens, ventilation chambers and party walls, among other things. They are a from the ground. In any case, there are various strategies that can be followed to species that is completely adapted to living up in the air and it is in fact only boost the presence of these birds in the city: during their breeding season that they use buildings to stay in and breed. They 1. Making the most of redevelopment or new building work to put up artificial are able to sleep as they fly. It is worth highlighting their ecological value in con- nests integrated into façades, which show a higher occupancy index than out- trolling insect populations. door artificial nests. COMMON SWIFT (Apus apus) They can be distinguished from swallows by their completely dark plumage and by their narrower, scythe-shaped wings. Nest: they occupy ventilation chambers, false ceilings, party walls and other structures, such as window-blind boxes, which they access through small cracks and holes. The sizes of their nests’ entrance holes are 5 cm in diameter (round) or 3 cm x 7 cm Photo: Sergi Garcia (rectangular). Phenology: they arrive in the spring and leave at the end of the summer. ALPINE SWIFTS (Tachymarptis melba) Redevelopment work on a building’s party wall in Carrer de Concepción Arenal. Observe the presence of They are notable for their white belly and neck, separated by a entrance holes for swifts on the upper part. Photo: Sergi Garcia brown pectoral strip, a feature which, along with being bigger than common swifts, distinguishes it from the latter. 2. Ensuring the redevelopment work on the buildings does not damage or block Nest: they prefer to use rain-protected party walls or the side ventilation holes or other structures that can be used by these birds. walls of buildings for building their nests. They form colonies that can contain a large number of individuals and form dormitories 3. Making the most of new building work to adapt structures such as nesting sub- where hundreds of non-breeding individuals group together, as strates for these species. can be found in the Camp Nou. The sizes of their nests’ entrance holes are 8 cm in diameter (round) or 5 cm x 10 cm (rectangular). Phenology: they arrive in March and leave at the start of November (later than common swifts). 252 253 INDEX INTRODUCTION 256 CONSERVATION INITIATIVES Preserving cracks in façades and stone walls 258 Preventing the presence of cats 259 Moderating the use of reaping and weeding machines in areas of use to fauna 260 Putting adhesives on windows in landscaped areas 262 IMPROVEMENT INITIATIVES Boosting green roofs and landscaped roof terraces 264 Beefing up plant cover on balconies, patios and roof terraces 266 Strengthening the creation of vertical gardens 267 Strengthening a quality shrub layer 268 Putting up nest boxes 270 Putting up feeding boxes 272 Putting up insect hotels 274 Putting up insect spirals 275 Boosting the presence of useful flora in patios, gardens and balconies 276 Creating bogs for swallows 278 Naturalising ponds and ornamental fountains 279 Creating rock piles 280 Construction of wood piles or pyramids 281 Accumulating litterfall 282 Putting up watering troughs 283 ANNEXE 1 Plants for butterfly gardens 284 ANNEXE 2 Diurnal butterflies 288 255 COURTYARDS, SMALL GARDENS, BALCONIES, TERRACES AND GREEN ROOFS IANNTNREOXDEUCTION ANNEXE There are a wide variety of types of green spaces in urbanised milieus, with mark- Interior gardens encourage biodiversity where, besides the more routine initia- edly different sizes and locations. Despite such heterogeneity, they share the fact tives, initiatives are carried out which are aimed at boosting biodiversity. Such that they are often subject to a large number of small initiatives that are favour- initiatives here notably include those that enable fauna to shelter, breed, feed or able to plants and fauna on the part of the public itself. Because they are mostly simply move around with ease from one place to another (playing a green-corri- private spaces, this encourages all those who enjoy them to take special care dor role). All of this is beneficial for insects, birds, reptiles, amphibians and small of them. Some are spaces for public use and belong to institutions, universities mammals; in short, the scope of the initiatives will depend on the possibilities or religious-order buildings and, as such, enjoy good maintenance too. Note in of each site. Some initiatives need a bit of space, as in the case of creating piles this broad range the more than 50 reclaimed block interiors in Barcelona, from of rocks or wood, but others, such as nest boxes, can be carried out on modest the Eixample district, spaces that have increased the presence of urban green in balconies and roof terraces. From the city’s perspective, it is not so important for highly densified areas. the initiatives to be very intense in some places, as they are carried out wherever they are feasible, though more modestly. Barcelona has a tradition of using balconies and roof terraces for a variety of Green roof Carrer Tarragona, 173 roles, including landscaping. The City Council is working to launch a series of reg- ulatory and technical terms and conditions for promoting the creation of green roofs. Green roofs represent a new stage of advancement in the city’s natural- isation which involves several environmental benefits, including capturing rain water and absorbing CO2, and dampening the effect known as “urban heat is- land”, which makes the city’s temperature higher than that of its surroundings. Moderating this effect results in a reduction of energy consumption derived from air-conditioning, besides creating a new urban landscape high up. Poble Espanyol 256 257 CXOXNXSERVATION INITIATIVES CXOXNXSERVATION INITIATIVES Preserving cracks in façades and stone walls for Preventing the presence of cats to minimise their conserving habitats for birds, reptiles and invertebrates impact on fauna Cat colony Columbretes wall lizard (Podarcis liolepis) Description/application Description/application > Holes must not be obstructed or cracks > The predatory instinct of cats poses a risk eliminated since these spaces allow the pres- to the preservation of urban biodiversity. Cats ence of animal life and offer places for birds, must therefore be relocated far away from lizards, geckos and invertebrates to breed and spaces where there is a clear aim to establish rear their young in. conservation programmes and improve biodi- versity. 258 259 CONSERVATION INITIATIVES Moderating the use of reaping and weeding Description/application machines in areas of use to fauna to prevent their Using reaping or weeding machines in areas of use to fauna, such as the sur- impact on fauna roundings of a pond or rocky area, can lead to high death rates among amphibian, reptile and invertebrate populations. > Care has to be taken when using such types of machinery during the breeding periods of fauna and maintenance work should be performed outside the breed period. In any case, if reaping or weeding work has to be carried out, it would be advisable to consider doing it from the outside in, to give fauna possibilities of escaping to shelter areas, and to cut as high as possible. 260 261 CONSERVATION INITIATIVES Putting adhesives on windows in landscaped areas Adhesives, shaped as birds-of-prey silhouettes, were traditionally used to alert birds of the presence of a predator and thereby prevent them from colliding with to prevent their impact on birds windows. While it is true that this can prove effective for small windows with suitable densities (10 cm of separation), by breaking their mirror effect, the same cannot be said with large-surface windows. There are two evident lines of work here. One for solving the problem of birds colliding against currently existing buildings, and the other for incorporating new criteria into the design of newly constructed buildings with translucent glass or incorporating screen prints inside that are visible to birds. Parc del Centre in Poblenou Description/application The latest studies conducted in northern European countries show that the problem of birds colliding with the windows of buildings is much more signifi- cant than previously believed and is actually one of the main causes of unnatural death among birds. The transparency and mirror effect glass panes have as im- ages of their environment, such as tree tops, gardens or even the sky itself, end up as a fatal trap for many species of birds, whether sedentary or migratory in Screen-printed glass the spring and autumn. Blackbirds, blackcaps, robins, chiffchaffs, thrushes and swifts, among other species, are affected by this problem. > To protect against such collisions adhesives need to be put on window panes to break their reflection. In this respect, it has recently been observed that the most effective measure it to put up strips of adhesive tape, 10 cm apart from one another. 262 263 IMPROVEMENT INITIATIVES Boosting green roofs and landscaped roof terraces to create a biodiverse habitat Green roof Zona Nord Library > When it comes to selecting species, account has to be taken of elements such as native plants or plants that are well adapted to the Mediterranean climate, and therefore of low maintenance; flower types and their nectar value; retaining atmospheric pollutants and their invasive or allergenic potential and soil avail- ability. Studies need to be conducted on the species of which these roofs and terrace roofs should be composed; the options are evidently diverse, but a good option in any case would be to use succulent or bulbous plants, such as wild garlic (Allium sp.) or species typical of fields and Mediterranean scrub. Common thatching grass (Hyparrhenia hirta), Mediterranean false-brome (Brachypodium retusum), Mediterranean stonecrop (Sedum sediforme), fennel (Foeniculum vul- gare) and viper’s bugloss (Echium vulgare) are a few good examples. (See Grass- Green roof Fàbrica del Sol es, fields and grasslands. Annexe 4: Mediterranean dry grasslands). Description/application > The benefits for biodiversity are higher where the designs of such spaces pro- vided for the introduction of a shrubby layer that increases the space’s structural Landscaped roofs and terrace roofs regarded complexity, provided the available soil permits this. as biodiversity spaces have to be geared to- wards creating a dense plant structure with a useful composition of flowers, to enable them to attract the interest of fauna and play, at the same time, a connecting role between green spaces. They are places colonised by flora and fauna spontaneously and rapidly become use- ful spaces for biodiversity. Bearded iris (Iris germanica) Narcissus (Narcissus sp.) Eastern gladiolus (Gladiolus communis) 264 265 IMPROVEMENT INITIATIVES IMPROVEMENT INITIATIVES Beefing up plant cover on balconies, patios and roof Strengthening the creation of vertical gardens to terraces to attract birds, reptiles and bats improve the city’s flora and fauna usefulness Urban allotment on the terrace roof of Vertical garden the Escola Nostra Senyora de Lurdes Description/application Description/application The opportunities offered by balconies, patios > The presence of free walls on balconies, in and roof terraces need to be taken advantage patios and on terrace roofs need to be exploit- of, to establish or strengthen their plant cov- ed so that invertebrates, reptiles and birds er and provide fauna with feeding, breeding can have places for sheltering, breeding and and resting spaces, while also increasing the feeding. city’s green infrastructure. An allotment, for example, turns terrace roofs and balconies > Species have to be planted to boost plant into spaces that attract pollinating insects covers in the form of climbing plants. (See and insectivorous birds, among other things, Shrub groups and hedges. Annexe 1: Shrubby by boosting biodiversity and connections be- plant of use to fauna). tween green spaces. It is therefore a very use- ful option. Escola de Jardineria Rubió i Tudurí work For further information please consult Barce- lona City Council’s Guide to living roof terraces and green roofs. http://cort.as/d21u 266 267 IMPROVEMENT INITIATIVES Strengthening a quality shrubby layer to promote its fauna-sheltering role Group of false olive tree (Phillyrea angustifolia) shrubs Green roof at Servei Estació Description/application We need to ensure that courtyards, but above all small gardens, have a quality shrubby structure that offers local fauna places for breeding, feeding and sheltering and which enables them to move between urban green spaces. > Native shrub species should be planted that have fewer maintenance needs and more interaction with local fauna, such as laurusti- nus (Viburnum tinus), mastic trees (Pistacia lentiscus), Mediterranean buckthorn (Rham- nus alaternus), strawberry trees (Arbutus un- Black hawthorn (Rhamnus lycioides) edo) and false olive trees (Phillyrea angustifo- lia). (See Shrub groups and hedges. Annexe 3: Parc del Laberint d’Horta Shrubby plants of use to fauna). 268 269 IMPROVEMENT INITIATIVES Putting up nest boxes to encourage the presence of forest insectivorous birds and bats Nest box for Eurasian blue tits Nest box for European robins Nest box for short-toed treecreepers • For small birds, nest boxes should be far > Artificial nests should be put up for bats. from the main trunk, to make it hard for po- New building systems and the dearth of ma- tential predators to access them. ture forests make it very difficult for these • Hole sizes will determine the presence of mammals to find suitable holes and cracks to one or another species. shelter in. Artificial nests can therefore be put • Nest boxes need to be maintained. Old nest up for both their activity (breeding) and hiber- boxes from previous seasons should be re- nation periods. There are many models of nest moved during the winter period, to prevent boxes for bats of various types on the market, the plugging-up of nest boxes, and also but,in any case, the general criteria for putting cleaned inside, where possible, to protect them up are as follows: Nest box for great tits (Parus major) against the presence of parasites, bacteria and fungi. • Height between 3 m and 5 m. Description/application • Facing south or south-west. It is advisable for nest boxes to receive between 5 and 7 > Nest boxes need to be put up, to offer nest- Nest boxes must be located in places where hours of sunshine a day. ing opportunities to certain species of insec- birds can safely breed. For this reason, the fol- • They can be hung from trees or building tivorous and forest birds which have difficul- lowing factors should be taken into account: façades, provided there are no obstacles ty in urban contexts finding breeding places, blocking the nests’ entry and exit holes. due mainly to a lack of mature trees. Great tits • Nest boxes should be put up in the middle (Parus major), European crested tits (Lophop- of the winter. That is when birds start to look hanes cristatus), Eurasian blue tits (Cyanistes for suitable nesting places. caeruleus), coal tits (Periparus ater) and short- • Nest boxes should face south or south-west, toed treecreepers (Certhia brachydactyla) are especially in cold and shaded areas, to cap- regular nest-box users. The educational po- ture the morning sunshine. tential of the initiative should be exploited • Nest boxes should be put up at a height of between 3 m and 7 m. 270 271 IMPROVEMENT INITIATIVES Putting up feeding boxes to provide birds with food > Feeding boxes should be located beyond the reach of cats and other preda- tors. during the winter period > Feeding boxes must be regularly cleaned. > Watering troughs with clean water should be provided. > Types of food: • Grain and seeds: wheat, barley, maize, millet etc. There are also commercial preparations. Granivorous birds from the finch family such as greenfinches, goldfinches and serins, as well as wood pigeons (Columba palumbus) and Eurasian collared doves (Streptopelia decaocto), will use them. • Dried seeds and nuts: peanuts, sunflower seeds etc. It is important for the dried seeds and nuts to be treated with anti-fungal products and to ensure they can withstand the elements. They will be greatly appreciated by tits and finches • Sweet fruit. Appreciated by common blackbirds (Turdus merula), song thrushes (Turdus philomelos) and Eurasian blackcaps (Sylvia atricapilla), among other species • Live worms: earthworms and cockroach larvae and mealworms for insectiv- orous birds such as black redstarts (Phoenicurus ochruros) and white wag- tails (Motacilla alba). • Salted or toasted products must not be given. Eurasian blue tit on a tubular feeding trough Description/application Under normal conditions, birds find the food they need for their development in the natural environment. In winter, however, given the low temperatures and scarcity of food resources, they can be offered a regular source of food and small birds therefore helped to get through harsh times. The educational potential of the initiative should be exploited > Food should only be provided during the winter period. Outside that period, any additional food in feeding boxes can be counter-productive, as it can create a dependency among birds that must be avoided. Home-made feeding bowl made from a coconut shell. Drainage holes are required to prevent the build-up of water. 272 273 IMPROVEMENT INITIATIVES IMPROVEMENT INITIATIVES Putting up insect hotels to boost the presence of Putting up insect spirals to boost the presence of pollinators in courtyards, gardens and balconies pollinators in courtyards, gardens and balconies Insect spiral. Permaculture group Bosc Turull Description/application Insect spirals are extremely useful structures for biodiversity which help to attract a large > Dry stone walls offer shelter for a large number of pollinating insects. With this goal number of invertebrates, small reptiles - such Insect hotel. Jardí Botanic in mind, it is important to work with plants as lizards and geckos - and amphibians, where Description/application whose flowers blossom over long periods and there are nearby sheets of water. All of these contain a notable nectar content and which will therefore find shelter among the cracks > Many hymenoptera species (ants, bees and are also perfectly adapted to the Mediterrane- and holes of the spiral, thereby considerably wasps) live in empty holes and can therefore an climate. increasing the space’s biodiversity. be provided with nesting substrates. There are numerous possible combinations both in > When making the final choice for the plant One option also worth considering is inserting the materials used (sawdust, wood, reed, clay, species that the insect spiral is to consist of, small insect hotels made up of trunks and oth- plant materials etc.,) and in the diameters of account should be taken of such aspects as er perforated plant materials into the spiral’s the holes. They host several species, depend- the presence or absence of irrigation systems, walls so solitary bees can find nesting sub- ing on these parameters. the degree of sunshine the structure receives, strates there. ornamental criteria, the environment and the > Account should be taken of the educa- use that the public makes of the space in > It is strongly advisable to use gabions as a tional potential of these constructions where question. In any case, planting aromatic spe- building element for stone walls in gardens if they are built with transparent materials that cies such as lavender, rosemary, thyme, sage, you are considering putting up an insect spiral enable monitoring of laid eggs, the growth of prostrate Canary clover, hyssop, santolina and and the environment’s urban-context dynam- larvae in their rearing cells and the emergence common shrubby everlasting can prove to be ics raise concerns over the possibility of acts of adults. Insect hotel using reed from the allotment extremely useful. (See annexe 1: Plants for of vandalism. butterfly gardens). 274 275 IMPROVEMENT INITIATIVES Boosting the presence of useful flora in courtyards, • Choose species that blossom in the spring, others that do so in the summer and others in the autumn, to ensure a long period of flowering. gardens and balconies to increase the presence of • Choose species with flowers of several colours. butterflies and other pollinating insects • Put together at least three or four units of each plant species. • Plant host species, such as legumes or grasses. • Offer empty spaces so ruderal species such as fennel, thistle and mallow can establish themselves there. • Create small bogs so butterflies can sip mineral salts from the earth. Jardí per a la biodiversitat. Parc de Joan Miró Hemerocallis sp. Parc del Torrent Maduixer Jardí per a la biodiversitat. Parc de Joan Miró Description/application Nectar-producing plants in courtyards, gar- dens and small balconies attract butterflies and other pollinating insects. What is more, some of these plants are used by adult butter- flies as host plants. (See annexe 1: Plants for butterfly gardens). > If you are considering building a butterfly garden, bear in mind the following: • Put it in a sunny place that is protected from Painted lady (Vanessa cardui) on purpletop vervain (Verbena Pea blue (Lampides boeticus) sipping from a Spanish broom the wind. bonariensis) (Spartium junceum) flower • Group together the chosen species accord- ing to their maintenance needs and giving Echium fastuosum priority to native plants. 276 277 IMPROVEMENT INITIATIVES IMPROVEMENT INITIATIVES Creating bogs for swallows to help them with building Naturalising ponds and ornamental fountains to their nests boost aquatic flora and fauna Monestir de Pedralbes’ irrigation pond Description/application Description/application Swallows from Africa arrive here every spring to remake or start building their A type of management should be carried out nests and enter their nesting and breeding period. based on the fact that it is the aquatic system itself that is self-regulated, through the natu- A good-quality bog is required for that purpose. ral balance of its fauna and flora. > Bogs have to be located in open spaces without very much vegetation. > If necessary, access and exit ramps should be installed so that amphibians can complete > It is advisable for the mud there to have a clayey texture so it is consistent their life cycles and other fauna that acciden- when it dries. tally fall in have a chance to get out and es- cape from drowning. There need to be struc- tures in place that connect the pond’s interior with the outside. 278 279 IMPROVEMENT INITIATIVES IMPROVEMENT INITIATIVES Creating rock piles to attract reptiles and invertebrates Building piles or pyramids of wood to attract wood- eating insects Rock pile. Tres Pins Plant Nursery Piled-up wood. Tres Pins Plant Nursery Description/application Description/application Rock piles create opportunities for mainly liz- Wood gives xylophagous (dead-wood-eating) ards and invertebrates to colonise them. Sun- insects opportunities for feeding, given that ny sites need to be found. they take part in decomposition processes of organic matter and are also at the bottom of the food chain for many groups of fauna. > Such wood can come from leftovers from pruning and small piles of wood can be opted for, as well as more elaborate constructions such as pyramids, which partially bury the base of vertically laid-out trunks. In such cas- es, besides their biodiversity-related aspects, it is worth considering the aesthetic value that they bring the site. 280 281 IMPROVEMENT INITIATIVES IMPROVEMENT INITIATIVES Accumulating litterfall to increase the number Putting up watering troughs to attract fauna in of invertebrate fauna courtyards, gardens or balconies Columbretes wall lizard (Podarcis liolepis) Description/application > Litterfall should be accumulated in garden areas that are rarely visited. That would speed up the organic matter’s natural decomposi- tion processes and increase biodiversity. Description/application > The availability of water in gardens, balco- nies and courtyards is becoming a key factor in determining the presence of local fauna. Watering troughs should be located in acces- sible places. Of course, their maintenance needs to be monitored to protect these water- ing troughs from turning into breeding points for mosquitoes. 282 283 ANNEXE 1 ANNEXE PLANTS FOR BUTTERFLY GARDENS Herbaceous plants Scientific name Common name Flowering Colour Value Scientific name Common name Flowering Colour Value Alyssum maritimum Sweet alyssum Sp/Sm/A/W White Nectar Parietaria officinalis Eastern pellitory- of-the-wall Sp/Sm Colourless HP of red admirals Aphyllanthes monspeliensis Blue aphyllanthes Sp Blue Nectar Psoralea bituminosa Pitch trefoil Sp/S/A Blue Nectar Aster sedifolius Michaelmas daisy A Blue Nectar Reichardia picroides Brighteyes Sp/Sm/A/W Yellow Nectar Asteriscus maritimus Canary Island Sp/Sm Yellow Nectar Saponaria ocymoides Rock soapwort Sp/Sm Rose Nectar daisy Scabiosa atropurpurea Mourningbride Sp/Sm/A/W Blue Nectar Centaurea sp. Centaury Sp/Sm Blue Nectar and HP of painted ladies Sedum album White stonecrop Sp/Sm White/yellow Nectar Centranthus ruber Kiss-me-quick Sp/S/A Purple Nectar Silybum marianum Milk thistle E Rose Nectar and HP of painted ladies Cirsium vulgare Creeping thistle E Rose Nectar and HP of painted ladies Sonchus tenerrimus Slender sowthistle Sp/Sm/A/W Yellow Nectar Crithmum maritimum Rock samphire Sp/Sm/A/W Yellow/green Nectar Tropaeolum majus Garden E Yellow/ HP of large white and small white Daucus carota Wild carrot Sp/S/A White Nectar and HP of painted ladies nasturtium orange butterflies Diplotaxis erucoides White rocket Sp/Sm/A/W White Nectar and HP of small cabbage Trifolium pratense Red clover Sp/S/A White Nectar and HP of dark clouded whites and bath whites yellow, pea blue and common blue Dittrichia viscosa False yellowhead A Yellow Nectar Urtica dioica Common nettle Sp/Sm Colourless Nectar and HP of red admirals Echium vulgare Viper’s bugloss Sp/Sm/A/W Blue Nectar Viola alba White violet Sp/W Blue Nectar Eryngium maritimum Sea holly Sp Blue Nectar Eryngium campestre Field eryngo Sp/Sm White Nectar Sp = spring, Sm = Summer, A = autumn, W = winter, HP = host plant Foeniculum vulgare Fennel E Yellow Nectar and HP of southern scarce swallowtails Galactites tomentosa Purple milk thistle Sp/Sm Rose Nectar and HP of painted ladies Heliotropium europaeum European turn- sole E White Nectar Hypericum balearicum Majorca St John’s wort Sp/Sm Yellow Nectar Lathyrus latifolius Perennial peavine Sm/A Rose Nectar Nectar and HP of southern scarce Lepidium draba Whitetop Sp White swallowtail and small cabbage whites Lotus corniculatus Common bird’s- Sp/S/A Yellow Nectar and HP of dark clouded foot trefoil yellow, pea blue and common blue Malva sylvestris Common mallow Sp/Sm Rose Nectar and HP of painted ladies Nectar and HP of dark clouded Medicago sativa Alfalfa Sp/S/A Blue yellow, pea blue, common blue and Lang’s short-tailed blue. 284 285 Aromatic plant Shrubs, climbing plants and bramble bushes Scientific name Common name Flowering Colour Value Scientific name Common name Flowering Colour Value Foeniculum vulgare Fennel Sm/A Yellow Nectar and HP of southern Anthyllis cytisoides N/A Sp/Sm Yellow Nectar scarce swallowtails Arbutus unedo Strawberry tree A/W White Nectar and HP of two-tailed pashas Helichrysum italicum Curry plant E Yellow Nectar Shrubby hare’s Helichrysum stoechas Curry plant Sp/Sm Yellow Nectar Bupleurum fruticosum ear Sp/Sm Yellow Nectar Hyssopus officinalis Hyssop Sm/A Blue Nectar Buxus sempervirens Boxwood Sp White Nectar Lavandula stoechas Spanish lavender Sp Blue Nectar Calluna vulgaris Common heather Sm/A Rose Nectar Marrubium vulgare Japanese mock orange Sp/A White Nectar Cornus sanguinea Common dogwood Sp White Nectar Lavandula angustifolia Lavender E Blue Nectar Crataegus monogyna Common Sp White Nectar and HP of scarce hawthorn swallowtails Lavandula stoechas Spanish lavender Sp Blue Nectar Erica arborea Tree heath Sp/W White Nectar Matricaria recutita Camomile Sp/S/A White Nectar Erica multiflora Heather A/W Pink/white Nectar Melissa officinalis Lemon balm Sp/Sm Colourless Nectar Hedera helix Common ivy A White Nectar and HP of holly blues Mentha suaveolens Apple mint E White Nectar Ilex aquifolium Common holly Sp/Sm White Nectar Origanum vulgare Orenga Sp/Sm Common mallow Nectar Laurus nobilis Sweet bay Sp White Nectar Rosmarinus officinalis Rosemary Sp/S/A Blue Nectar and HP of Lang’s short- tailed blue Lonicera implexa Minorca honeysuckle Sp White Nectar and HP of two-tailed pashas Ruta chalepensis Fringed rue Sp/Sm Yellow Nectar and HP of southern scarce swallowtails Phlomis herba venti Rough-leaved Jerusalem sage Sp/Sm Yellow Nectar Ruta graveolens Common rue E Yellow Nectar and HP of southern scarce swallowtails Lycium europaeum Box-thorn Sp/Sm Lilac/white Nectar Salvia officinalis Sage Sp Blue Nectar Pistacia lentiscus Mastic tree Sp Red/yellow Nectar Santolina Cotton lavender Sp/Sm Yellow Nectar Prunus spinosa Blackthorn Sp White Nectar and HP of scarce chamaecyparissus swallowtails Satureja calamintha Lesser Calamint Sm/A Blue Nectar Quercus coccinea Scarlet oak Sp Yellow Pollen Satureja montana Winter savory Sm/A White Nectar Rhamnus alaternus False olive Sp Yellow/green Nectar and HP of Cleopatra butterflies and common brimstones Thymus vulgaris Common thyme Sp Blue Nectar and HP of Panoptes blue Rosa canina Dog-rose Sp Rose Nectar Sp = spring, Sm = Summer, A = autumn, W = winter, HP = host plant Rosa sempervirens Evergreen rose Sp White Nectar Rubus idaeus Red raspberry Sp/Sm White Nectar Shrubby scrubs Rubus ulmifolius Elmleaf blackberry Sp White/pink Nectar and HP of holly blues Sambucus nigra Elderberry Sp White Nectar Scientific name Common name Flowering Colour Value Sarothamnus scoparius Scotch broom Sp Yellow Nectar Asparagus acutifolius Wild asparagus E Yes Spartium junceum Spanish broom Sp Yellow Nectar and HP of pea blues Cistus albidus Grey-leaved cistus Sp Pollen Green hairstreak Ulex parviflorus Gorse Sp Yellow Pollen Cistus monspeliensis Montpellier cistus Sp Pollen Viburnum tinus Laurustinus W/Sp White Nectar Cistus salviifolius Sage-leaved rock-rose Sp Pollen Green hairstreak Vitex agnus-castus Chaste tree Sp/Sm Blue Nectar Dorycnium pentaphyllum Prostrate Canary clover Sp/Sm Yes Sp = spring, Sm = Summer, A = autumn, W = winter, HP = host plant Sp = spring, Sm = Summer, A = autumn, W = winter, HP = host plant 286 287 ANNEXE 2 DIURNAL BUTTERFLIES Família papilionidae Butterflies are regarded as bio-indicators as they are highly sensitive to envi- ronmental changes. Such features, along with the fact they are greatly socially OLD WORLD SWALLOWTAIL (Papilio machaon) accepted and easy to monitor, have helped to establish butterfly monitoring net- works. Description: besides being easily identifiable by its size, this is one of the most spectacular butterflies owing to its yellow- More specifically, a butterfly-population monitoring project was launched in ish colour and black vein markings and because each of its Catalonia in 1994, called the Catalan Butterfly Monitoring Scheme (CBMS). It in- wings has a red-and-yellow pigment pit and a tail. It is also volves discovering the changes in butterfly numbers by conducting weekly visual noted for the way it flies. censuses to relate them to environmental factors. Phenology: univoltine, bivoltine or trivoltine depending on the We should also mention that while it is true that there are no big differences be- latitude, altitude and climatology of the season. At our lati- tween native and alien plants as far as the nectar value of their flowers goes, the tudes: trivoltine Can be observed from February to October. caterpillars of many of the butterflies found in the city’s parks and gardens use specific species or families of native plants for feeding on. Habitat: Common in ruderal areas and fields. Its presence is determined by its host plant. Preliminary concepts: Host plant: fennel (Foeniculum vulgare), wild carrot (Daucus carota), tree thorough-wax Voltinism: this is the number of generations a species of butterfly goes through (Bupleurum fruticescens), parsley (Petroselinum crispum) and rue (Ruta graveolens and R. chalep- in the space of a year. So, depending on the species and climate conditions, there ensis), among other species. can be univoltine, bivoltine, trivoltine or polyvoltine butterflies, depending on whether they present one, two, three or more generations over the year. Curiosities: males from this species exhibit hilltopping. Hilltopping: this is a form of behaviour presented by the males of some species which involves defending mating territories in geographically high-up areas such as a hill or mountain tops. Once the territories have been established, each male will defend its area aggressively and push out any other male. SCARCE SWALLOWTAIL (Iphiclides feisthamelii) The main species that can be found in Barcelona’s parks and gardens are: Description: they have long tails that end with a white point and a zebra pattern that makes them unmistakeable. Phenology: at our latitudes: bivoltine. Can be observed from March to the end of August, although they can give rise to a partial third generation in low areas in September. Habitat: very diverse, from shrubby areas or woody borders to herbaceous and open zones as well as rocky slopes. They are Photo: Wikimedia also common in ruderal areas and fruit-tree fields. Host plant: species from the genus Prunus, such as wild cherry trees (Prunus avium), plum trees (P. domestica) and peach trees (P. persica). Common hawthorn (Crataegus monogyna), common pear tree (Pyrus communis) and cultivated apple tree (Malus domestica) are also its host plants. Curiosities: males exhibit hilltopping behaviour. 288 289 Family Pieridae DARK CLOUDED YELLOW (Colias crocea) Description: orangey yellow in colour, with black spots. This LARGE WHITE (Pieris brassicae) species presents sexual dimorphism: in contrast to males, fe- males have yellow spots along their wings’ black borders. . Description: White with black points on its front wings. It pre- sents sexual dimorphism, as its females have two round black Phenology: polyvoltine. Can be observed from March to No- marks on the obverse of its front wings, marks that are absent vember. Migratory. in males. Habitat: common in fields and open spaces with abundant Phenology: polyvoltine. Can be observed from March to October. flowers. Migratory. Host plant: a great variety of species from the legume family Habitat: very common in gardens, crop areas and ruderal zones such as alfalfa (Medicago sativa), red clover (Trifolium pratense) and other species from the genera with nectar-rich flowers, such as thistles and centaureas. Coronilla, Astragalus, Vicia and Anthyllis, to name but a few. Host plant: many species of crucifers and capparaceae, such as caper bush (Capparis spinosa), and Tropaeolaceae, such as gar- den nasturtium (Tropaeolum majus). Curiosities: its caterpillars are a pest in cabbage crops and not- COMMON BRIMSTONE (Gonepteryx rhamni) ed for their aposematic colouration, that is, their set of colours warning predators of their chemical defences. Its larvae are Description: presents a sexual dimorphism in its colouration, It lay its eggs on the underside of parasitised by several species of hymenoptera. as males are lemon-yellow in colour whereas females are pale cabbage leaves. green. Its females are practically indistinguishable from Go- nepteryx cleopatra females. Phenology: univoltine. It hibernates as an adult and can there- fore be observed from February up to October. SMALL WHITE (Pieris rapae) Photo: Wikimedia Description: as it suggests, it is smaller than the large white. It Habitat: very common in humid woody areas, although thanks is white or yellowish and also presents black spots at the tips of to its mobility it also appears in markedly arid areas. its wings. Host plant: Mediterranean buckthorn (Rhamnus alaternus) and other species from the same genus. Phenology: polyvoltine. Can be observed from March to Novem- ber. Curiosities: undergoes vertical migration in Mediterranean areas in the summer, looking for sources of nectar from lilac-coloured flowers such as those of viper’s bugloss (Echium vulgare). Habitat: very common in open areas in gardens and allotments and in ruderal environments. Host plant: preferably crucifers such as wild cabbage (Brassica oleracea), but also chenopodiaceae and capparaceae, among other plants. Curiosities: it is a common pest in cabbage crops, which its caterpillars feed on. Its caterpillars are frequently parasitised by hymenoptera. 290 291 Family Lycaenidae CLEOPATRA BUTTERFLY (Gonepteryx cleopatra) Description: the species presents a pronounced sexual dimor- phism whereby the males stand out for the large orange spot, COMMON BLUE (Polyommatus icarus) which is absent in females, on their front wings. G. Cleopatra males can be easily distinguished from G. rhamni males by the Description: it is the commonest of all the gossamer-winged absence of these orange spots. butterflies and, as with the other species in this family, its fe- males are brown and more difficult to see whereas its males Phenology: bivoltine. It also hibernates as an adult and can are electric sky blue. therefore be observed from February to August. Photo: Wikimedia Phenology: polyvoltine. Can be observed from March to Octo- ber. Habitat: very common in arid and dry Mediterranean environments. Habitat: it is a species capable of colonising very different en- Host plant: Mediterranean buckthorn (Rhamnus alaternus) vironments such as fields, abandoned crops and ruderal areas. Curiosities: undergoes vertical migration in Mediterranean areas in the summer, looking for sources Host plant: several species of legumes such as red clover (Trifolium pratense), alfalfa (Medicago of nectar from lilac-coloured flowers such as those of viper’s bugloss (Echium vulgare). sativa), common bird’s-foot trefoil (Lotus corniculatus) and Spanish broom (Spartium junceum). WESTERN DAPPLED WHITE (Euchloe crameri) PEA BLUE (Lampides boeticus) Description: its upper side is white with black spots and its lower side is silvery with well-defined grey and greenish spots. Description: its males are violet blue and its females grey brown. The underside of its wings is brown with wavy white Phenology: bivoltine. Can be observed from February to October. lines and is notable for its highly visible white stripe. Also no- Habitat: appears in lowland farm and ruderal areas. table are the tails on its back wings. Host plant: various crucifer. Phenology: polyvoltine. It can be observed from April to Octo- ber, except when it hibernates as an adult. Migratory. Habitat: common in markedly arid areas such as scrubs and maquis shrubland where Spanish broom is found. And in cul- tivated and ruderal areas with flowers. BATH WHITE (Pontia daplidice) Host plant: many species of legumes such as Spanish broom (Spartium junceum) and alfalfa (Med- Description: resembles the western dappled white. They can be icago sativa). distinguished by examining whether the upper border of their front wings have crosswise stripes (E. crameri) or not (P. daplid- Curiosities: it can be a serious pest for peas (Pisum sativum). Male exhibit hilltopping behaviour. ice). The pattern on the underside of the wings is also different. Phenology: polyvoltine. Can be observed from March to October. Migratory. Habitat: ruderal and arid environments. Host plant: Reseda lutea and several crucifer. 292 293 Nymphalidae Family LANG’S SHORT-TAILED BLUE (Leptotes pirithous) Description: Resembles pea blue but can be distinguished from it as it is smaller and lacks the white stripe found on the PAINTED LADY (Cynthia cardui) other’s back wings. Its males and females have the same col- ouring as their pea blue counterparts. Description: the underside of the wings have a reddish back- ground with white and black spots. Its back is clearer, with Phenology: polyvoltine. Migratory. It arrives in Catalonia from small blue pigment pit on the lower part. the African continent in May or June and can be observed until October. Phenology: polyvoltine. Can be observed from April to Novem- ber. Migratory par excellence, it comes over in the spring, from Habitat: ruderal borders and areas, and also abundant in al- north Africa, to breed in the Mediterranean. falfa and red clover fields. Habitat: shows a preference for open and ruderal areas with Host plant: alfalfa (Medicago sativa), red clover (Trifolium pratense), gorse (Ulex parviflorus) and thistles. Even so, thanks to its considerable mobility, it can be rosemary (Rosmarinus officinalis). found in very different environments. Curiosities: pea blue and Lang’s short-tailed blue fly fast and in a way that is difficult to distinguish. Host plant: thistles from the genera Cirsium, Cardus and Galactites, but also genera such as Echium, Malva and Urtica. Curiosities: every few years in mid-May, a huge number of them appear, moving north. GERANIUM BRONZE (Cacyreus marshalli) Description: it has a brown back along with grey and brown stripes on the underside of its wings. RED ADMIRAL (Vanessa atalanta) Phenology: Can be observed from April to October. Description: black with white and red spots. Habitat: towns and cities where geraniums are used as an or- Phenology: univoltine. Can be observed from March to Octo- namental plant. ber. Migratory. Host plant: geraniums (Pelargonium sp.). Habitat: very diverse, though common in humid and stream areas. Curiosities: a species introduced from South Africa in 1990 when geraniums were imported to the Balearic islands. Its larvae prefer to feed on flowers and buds, though it can affect any part of the Host plant: nettles and eastern pellitory-of-the-wall. plant above ground. Curiosities: a large number can be seen arriving in October and November, hailing from northern and central Europe, which come over to hibernate in the Mediterranean area. The offspring of these develop during the winter to give rise to a generation appearing in March-April that will subsequently colonise central and northern Europe. 294 295 TWO-TAILED PASHA (Charaxes jasius) WALL BROWN (Lasiommata megera) Description: it is Europe’s largest diurnal butterfly and one of Description: brown with orangey spots. its most spectacular. It is brown with a wide orangey margin dorsally and striped ventrally. Also notable are the two tails Phenology: polyvoltine. Can be observed from February to No- on its back wings. vember. Phenology: bivoltine. The first generation is from May to July Habitat: very diverse, including dry fields, fields with flower, and the second from August to October. ruderal areas, rocky areas or clearings in forest areas. Habitat: Mediterranean woody and maquis areas with straw- Host plant: various grass genera that include Brachipodium berry trees. It is especially abundant where there are cork and Agrostis. Photo: Wikimedia oaks. Curiosities: it resembles speckled wood, even though wall brown shows a preference for drier and sunnier environments. Males exhibit hilltopping behaviour. Host plant: Strawberry tree (Arbutus unedo) Curiosities: this species is strongly territorial and exhibits hilltopping behaviour. Males and females are attracted by the alcohol produced from fermenting strawberry tree fruit, which enables them to locate strawberry trees and lay their eggs in their leaves so their caterpillars can feed on them until SPANISH GATEKEEPER (Pyronia bathseba) they become pupae. They can often be seen sipping mineral salts over excrement. Description: it has orange wings with brown edges and a black pigment pit on its front wings, as well as pigment pits on its back wings, which distinguishes it from P. cecilia. The under- side of its back wings is noted for the creamy band traced by SPECKLED WOOD (Pararge aegeria) highly visible pigment pits, another feature for distinguishing the two species. Description: brown with orangey spots. Phenology: univoltine. Can be observed from April to July. Photo: Wikimedia Phenology: polyvoltine. Can be observed from February to No- vember. Habitat: fields, thickets and open woods. Habitat: Humid areas, brooks, gardens and woods. Shows a Host plant: Mediterranean false-brome (Brachypodium retusum) and common thatching grass preference for shaded areas where its males, which are very (Hyparrhenia hirta). territorial, can frequently be observed sunbathing on leaves and forest floors. Host plant: various grasses that include Brachipodium, Agrostis and Cynodon. 296 297 BIBLIOGRAPHY General SOUTHERN GATEKEEPER (Pyronia cecilia) • Barcelona Biodiversitat urbana. Martí Boada, Laia Capdevila. Centre d’Estudis Description: its wings are orange with brown edges and a Ambientals. UAB. black pigment pit on its front wings. Unlike P. batsheba, it has • Els espais urbans. Manual de gestió d’hàbitats per a la fauna vertebrada. Bar- no pigment pits on its back or on the underside of its back celona Provincial Council. wings. • Fauna de Barcelona. Amfibis, rèptils i mamífers. Barcelona City Council • Guia de natura de Barcelona. Aproximació a la història de la natura a la ciutat. Phenology: univoltine. Can be observed from July to Septem- Margarita Parés i Rifà. ber. • G uia de natura del parc de Collserola. Parc de Collserola. • Guía para atraer a las aves a su jardín. Editorial Tikal. Photo: Wikimedia Habitat: thickets and dry fields. • Inventari dels mamífers, aus, rèptils, amfibis i peixos dels parcs de Barcelona 2008. Galanthus. Host plant: common thatching grass (Hyparrhenia hirta) and • Manual de la conservació de la biodiversitat en els hàbitats agraris. Catalan Mediterranean false-brome (Brachypodium retusum). Environment and Housing Ministry. Generalitat of Catalonia • Natura al teu jardí. Albert Ruhí i Vidal. Editorial BRAU edicions i Oryx. • Ocells de Barcelona. Barcelona City Council. • Plan de acción para los parques y zonas verdes urbanas de Santander: Santander City Council SEO/Birdlife. • Qualitat ecològica dels parcs urbans de la ciutat de Barcelona. Propostes de IBERIAN MARBLED WHITE (Melanargia lachesis) gestió segons criteris biològics dins el Pla estratègic del verd. Anna Torné, Joan Carles Senar. Museu de Ciències Naturals de Barcelona. ICUB. Description: white with black spots. Phenology: univoltine. Can be observed from May to July. Lined Trees Habitat: shrubby and dry herbaceous areas with flowers. • Ecologia i Conservació dels ocells forestals. Un manual de gestió de la biodi- versitat en boscos catalans. Jordi Camprodon. Host plant: various grass genera that include Brachipodium, • Els ratpenats de Catalunya. Carles Flaquer i Xavier Puig. BRAU editorial. Agrostis and Dactylis. • Gestió de l’arbrat viari de Barcelona. Barcelona City Council. • Llibre blanc sobre control de plagues en espais verds. Catalan Ministry of Agri- culture, Livestock, Fishing and Food. Generalitat of Catalonia Useful addresses: • Our environment’s animals: Birds-Xtec www.xtec.cat • Discover bats www.ratpenats.org • Natural enemies in our urban green spaces. Xavier Pons, B. Lumbierres. Uni- versity of Lleida http://agricultura.gencat.cat/web/.content/de_departament/de10_publica- cions_dar/de10_01_agricola/documents/fitxers_estatics/enemics_naturals_ espais_urbans.pdf • Catalan Flora www.floracatalana.net • Galanthus www.asgalanthus.org • Catalan Institute of Ornithology (ICO) www.ornitologia.org • Granollers Natural Sciences Museum www.museugranollersciencies.org 298 299 LINED TREES LINED TREES Shrub groups and hedges City allotments • G uia dels arbustos dels Països Catalans. Ramon Pascual. Cossetània Edicions. • Agenda del huerto y el jardín ecológicos. M. Bueno, J. Arnau. Barcelona RBA • P lantes mediterrànies. Josep M. Panareda Clopés. BRAU edicions. Integral. • P rojecte sobre la reducció de la densitat de l’arbrat i estassada del sotabosc • El huerto ecológico fácil. G. Caballero de Segovia. Palma de Mallorca, 2002. en la franja perimetral de baixa combustibilitat de la urbanització Mas Guim- • El huerto familiar ecológico: la gran guía práctica del cultivo natural. M. Bueno. bau (Barcelona). Municipal Forest-Fire Prevention Office. Barcelona RBA. • Guide to landscape integration. Urban and peri-urban allotments. Girona City Useful addresses: Council. Generalitat of Catalonia • Practical guide to ecological horticulture: school allotments. Schools Agenda • Our environment’s animals: Birds-Xtec www.xtec.cat 21. Barcelona City Council. • S tudy on invasive species in Barcelona and the proposal for alternative spe- • Guide to phytosanitary products for 2002. General Manager’s Office for Agri- cies. Barcelona City Council http://cort.as/d1YE cultural Production and Rural Innovation. Plant-Health Service at the Catalan • C atalan Flora www.floracatalana.net Ministry of Agriculture, Livestock and Fishing. Generalitat of Catalonia • Catalan Natural History Institute www.iec.cat/Bages/ • L’Hort urbà: plantes aromàtiques. Manual de cultiu de plantes medicinals i • C atalan Institute of Ornithology (ICO) www.ornitologia.org aromàtiques en balcons i terrats. Josep M. Vallès. Ediciones del Serbal. • Plantas compañeras en el huerto ecológico. Fertilidad de la Tierra. • Royal Decree 1311/12, establishing the framework of action for a sustainable Grasses, fields and grasslands use of phytosanitary products, and the Register of Phytosanitary Products authorities by Spain’s Ministry of Agriculture, Food and Environment. • Biodiversidad en espacios urbanos: alternativas al uso extensivo de césped • Un hort per ser feliç. Marc Estévez Casabosch. Editorial Ara Llibres. en el contexto mediterráneo. María del Puy Alonso Martínez. University of Évora. Useful addresses: • E l porc senglar a la ciutat de Barcelona: incidències i recomanacions Servei d’Ecopatologia de Fauna Salvatge (SEFaS). Barcelona City Council. • Bichelos www.bichelos.com • Guia dels enemics naturals en els diferents cultius a Catalunya. Catalan Min- • Botanical-online www.botanical-online.com istries of Agriculture, Food and Rural Action. • J ardí dels bons endreços www.canroldor.blogspot.com • Technological gardening regulation: NTJ 08S Sowing and lawns. • Technological gardening regulation: NTJ 14G Maintaining non-sports lawns and fields. Aquatic environments and ponds • Revalorización de la biodiversidad en el espacio urbano mediterráneo. María del Puy Alonso Martínez. Conama 2014 Congreso Nacional del Medio Ambi- • River spaces. Environment diagnosis manual. Area of Environment. Barcelona ente. Provincial Council. • Study on Barcelona’s aquatic ecosystems. Barcelona Urban Ecology Agency. Useful addresses: Barcelona City Council. • T he ecological importance of ponds. 2009. Catalan Ministry of Environment. • O ur environment’s animals: Birds-Xtec www.xtec.cat Generalitat of Catalonia • Diari Apícola Ecolluita www.ecolluita.blogspot.com • Catalonia’s exotic species. EXOCAT 2012. CREAF, Generalitat of Catalonia. • Natural enemies in our urban green spaces. Xavier Pons, B. Lumbierres. Uni- • Royal Decree 630/2013, Spanish catalogue of invasive exotic species. versity of Lleida: http://agricultura.gencat.cat/web/.content/de_departament/ de10_publicacions_dar/de10_01_agricola/documents/fitxers_estatics/ene- mics_naturals_espais_urbans.pdf • F avoriser les abeilles sauvages et la nature en ville. Ecological guide to urban and peri-urban green spaces http://ec.europa.eu/environment/life/project/ Projects/index.cfm?fuseaction=home.showFile& rep=file&fil=URBANBEES_ guide_gestion_ecologique_0.pdf • Living landscapes www.paisatgesvius.org • Ruralcat www.ruralcat.net 300 301 Useful addresses: • Guide to living roof terraces and green roofs. Barcelona City Council. http://cort.as/d21u • Animals and biodiversity in Barcelona: conserving amphibians: • Papallones de la Serralada de Marina. Barcelona Provincial Council. http://w110.bcn.cat/portal/site/MediAmbient • Leaflet on the Collserola’s butterflies • A quàtiques Vilassar www.viveristes.cat • Galanthus www.asgalanthus.org Useful addresses: • Garden Alzinar www.alzinar.com • Grup de Naturalistes d’Osona www.gno.cat • Amics del jardí de papallones de Ca l’Arnús www.alocnatura.org • J ardí de bons endreços. www.canroldors.blogspot.com.es • Our environment’s animals: Birds-Xtec www.xtec.cat • M acroinvertebrates II. Consortium for the defence of aquatic fauna in the • Catalan Butterfly Monitoring Scheme www.catalanbms.org Besòs basin www.besos.cat • Discover bats www.ratpenats.org • Projecte Basses del Grup de Naturalistes d’Osona www.ichnosona.iec.cat/ • Catalan flora www.floracatalana.net • Projecte Rius www.projecterius.org • Galanthus www.asgalanthus.org • Vivers Carex www.carex.cat • Catalan Institute of Ornithology www.ornitologia.org • Granollers Science Museum www.museudegranollersciencies.org/caixes-niu/ • Nests-Welcome to nests www.nius.cat/ocells-i-boscos Cliffs, walls and party walls • w ww.sostenibilitatbcn.cat/attachments/article/ • Catalogue of spaces of natural interest in the city of Barcelona. Depana and Barcelona City Council. • Guideline criteria for exceptional initiatives in the face of conflicts created by the presence of protected fauna in the urban environment. General Manager’s Office for the Natural Environment. Generalitat of Catalonia • Buildings and biodiversity. Barcelona City Council • B uildings and biodiversity. Generalitat of Catalonia • The biological role of dry stone walls. Naturalea. Albert Sorolla Edo. Useful addresses: • Fauna in buildings www.faunaenedificis.gencat.cat • Galanthus www.asgalanthus.org • http://agricultura.gencat.cat/ca/ambits/medi-natural/fauna-flora-ani- mals-companyia/fauna- autoctona/fauna-salvatge-protegida-medi-urba/as- sessorament-tecnic/exemples-nius- artificials-caixes-niu/ • h ttp://agricultura.gencat.cat/ca/ambits/medi-natural/fauna-flora-ani- mals-companyia/fauna- autoctona/fauna-salvatge-protegida-medi-urba/ problemes-solucions/criteris-compatibilitzacio-fauna-protegida-edificis/ Courtyards, small gardens, balconies, terraces and green roofs • Bird-Safe Building guidelines. Audubon Minnesota. • Beginner’s file. Catalan Butterfly Monitoring Scheme • Favoriser les abeilles sauvages et la nature en ville. Ecological guide to urban and peri-urban green spaces http://ec.europa.eu/environment/life/project/ Projects/index.cfm?fuseaction=home.showFile& rep=file&fil=URBANBEES_ guide_gestion_ecologique_0.pdf 302 303 Dedicated to all the gardeners from the Barcelona Municipal Institute of Parks and Gardens, whose work has been contributing towards the conser- vation and improvement of the city’s natural heritage. Published by: Area of Urban Ecology. Barcelona City Council. 2016 Director of Green Spaces and Biodiversity: Xavier Hernández Technical content: Octavi Borruel Drafted by: Albert Punsola and Octavi Borruel Technical coordination: Teresa Garcerán, Margarita Parés, Montse Rivero and Coloma Rull Technical revision: Lourdes Carreras, Xavier Hernández, Izaskun Martí and Esther Murillo Collaborators: Jordi Catalán, Sergi García, Xavi Gassó, Àngels Martínez, Mari Pau Navarro, Pep Ordóñez, Guillem Pascual, José Antonio Rodríguez and Josep Rovira Editorial coordinator: Lis Francés Graphic design and layout: Endoradisseny Special thanks to: Professionals from Parks and Gardens and other experts were consulted for this manual. We are grateful to all of them. Especially: Lluís Abad, from the Barcelona Municipal Institute of Parks and Gardens; David Bertran, from the Barcelona Botanical Gardens; Xavier Ferrer, from the University of Barcelona; Sergi Herrando and Marc Antón, from the Catalan Institute of Ornitho- logy; Santiago Lavín and Jorge López, from the Wild Fauna Eco-Pathology Service at the UAB; Tomás Montalvo, from the Barcelona Public Health Agency; Elena Muñoz, Cos d’Agents Rurals; Quim Muñoz, from the Granollers Natural Sciences Museum; Javier Quesada, from the Barcelona Natural Sciences Museum. The contents of this publication are subject to an Attribution-ShareAlike (by) licence. This allows any use of the work, including for commercial purposes, as well as the creation of derived works, which may also be distributed without any restrictions, provided the source is cited. The full licence may be consulted at: http://creativecommons.org/licenses/by/4.0/deed.ca ajuntament.barcelona.cat/ecologiaurbana twitter.com/BCN_Ecologia