Adaptive governance to promote ecosystem services in urban green spaces

Managing urban green space as part of an ongoing social-ecological transformation poses novel governance issues, particularly in post-industrial settings. Urban green spaces operate as small-scale nodes in larger networks of ecological reserves that provide and maintain key ecosystem services such as pollination, water retention and infiltration, and sustainable food production. In an urban mosaic, a myriad of social and ecological components factor into aggregating and managing land to maintain or increase the flow of ecosystem services associated with green spaces. Vacant lots (a form of urban green space) are being repurposed for multiple functions, such as habitat for biodiversity, including arthropods that provide pollination services to other green areas; to capture urban runoff that eases the burden on ageing wastewater systems and other civic infrastructure; and to reduce urban heat island effects. Because of the uncertainty and complexities of managing for ecosystem services in urban settings, we advocate for a governance approach that is adaptive and iterative in nature—adaptive governance—to address the ever changing social order underlying post-industrial cities and offer the rise of land banks as an example of governance innovation.     

Nest selection by red-headed woodpeckers across three spatial scales in an urban environment

Forest habitat is important for a variety of woodpecker species, and is under pressure from urbanization. Red-headed Woodpeckers (Melanerpes erythrocephalus; RHWO) were once abundant across Eastern North America, and their populations have been declining since the 1960s. Their distribution encompasses urban centers, and since urban habitats differ from natural forest areas, our goal was to understand RHWO nest-site selection in an urban context. We addressed two main questions 1) what are the characteristics of RHWO nest selection across multiple spatial scales and 2) how do RHWO nest tree characteristics in city parks compare to those in forest preserves? This work was done in Cook County, IL, which includes Chicago, the third-largest city in the USA by population. We examined 34 RHWO nest trees used between 2010 and 2013, their surrounding habitat, and the landscape within a 1 km radius. Used trees and habitats were compared to paired unused trees and habitats, and landscape-scale characteristics were compared to random locations. Advanced decay of the nest tree, low canopy cover and increased presence of fungus on trees in the surrounding habitat were the best predictors of RHWO nesting in the area. Nests were most commonly found in forested areas outside of dense urban areas. However, we did not detect significant differences in the characteristics of the nest trees located in forest preserves and city parks. Our findings are consistent with nest selection studies in rural and natural areas, suggesting that forest habitats in metropolitan landscapes can support RHWO nesting.     

Functional connectivity in urban landscapes promoted by <Emphasis Type="Italic">Ramphastos toco</Emphasis> (Toco Toucan) and its implications for policy making

The scarcity of green areas in urban landscapes hinders connectivity among sites reducing the flux of organisms and seed dispersal. Ramphastos toco is an effective plant disperser in tropical landscapes, playing an important role in conserving plant connectivity. In this study we combined two methods of landscape connectivity analysis, in a way not yet explored, to assess the potential contribution of Ramphastos toco to enhancing connectivity among urban vegetation patches. We used spatial modeling techniques to evaluate least cost routes, or those that facilitate bird movement through green urban areas, in Belo Horizonte, a city in Southeast Brazil. We also assessed the relative importance of forest patches for conserving both bird and seed dispersal fluxes using the integral index of connectivity. The resulting least cost route of greater accessibility for the species included in its course an important forest patch under environmental licensing for the construction of a residential condominium. The number of green urban areas covered by forest, of highest habitat quality for the species, summed to 155 patches. Of this total only 5.2% were relevant for regional connectivity, while the four most important patches are targeted by the city’s expansion plans. Ramphastos toco is an effective connector for tropical green urban areas given its adaptability, wide range of movement and seed dispersal effectiveness. We emphasize the need for incorporating ecological knowledge and the prioritization of green areas into city planning, since current expansion projects jeopardize forest patches that are crucial to the functional connectivity of the urban landscape.     

Conservation-priority grassland bird response to urban landcover and habitat fragmentation

As urbanization in the landscape increases, some urban centers are setting aside habitat for wildlife. This habitat may be particularly valuable to declining or conservation-priority species. One group in particular need of conservation actions that may benefit from habitat located in urban areas is grassland birds. Declines of grassland bird species have been particularly severe in the Midwestern U.S., where most grassland cover has been lost, fragmented, and surrounded by unsuitable habitat. Conservation efforts have focused on protecting large grasslands surrounded by minimal amounts of trees and development. Although urban development is considered hostile to grassland birds, this assumption has received little attention. In heavily fragmented landscapes where habitat is limited, urban grasslands may be of significant value to grassland birds. We examined grassland bird response to development and additional landscape and habitat variables in the greater Chicago metropolitan area. In 2012 and 2013, we surveyed bird communities in grassland patches along a gradient of urbanization and patch sizes. Density of Savannah Sparrows (Passerculus sandwichensis) increased with amount of development, while density of Sedge Wrens (Cistothorus platensis) decreased. Development did not appreciably impact Bobolinks (Dolichonyx oryzivorus), Dickcissels (Spiza americana), Eastern Meadowlarks (Sturnella magna), Grasshopper Sparrows (Ammodramus savannarum), or Henslow’s Sparrows (Ammodramus henslowii). Patch size had a positive effect on species densities. These results indicate that for many conservation-priority grassland birds, urban landcover surrounding grasslands generally has neutral rather than negative effects on habitat use. Therefore, grasslands in developed landscapes may provide valuable contributions to regional conservation efforts.     

Suitability of biodiversity-area and biodiversity-perimeter relationships in ecology: a case study of urban ecosystems

Urban areas are probably the most fragmented environments with respect to the presence of semi-natural habitats and shape of these habitats may be significantly affected by urbanization. Patch perimeter in landscape or habitat studies is much less popular to study than patch area. The studied sites were situated in the industrial city of Pardubice, which is one of the ten largest cities in the Czech Republic with nearly 100,000 inhabitants. In total, 40 grasslands were studied within a circular area of 314 km². Butterflies and beetles with diurnal activity were studied during timed survey walks. A Simultaneous autoregressive model was used for test of the effect of biodiversity-area and biodiversity-perimeter relationships and for exclusion of potential bias caused by spatial autocorrelation. The models including patch perimeter performed better than those using patch area in explaining species richness, abundance and diversity of investigated organisms and were less influenced by spatial autocorrelation. The main conclusion and recommendation of the present study is that researchers should pay more attention to the possible influence of the patch perimeter as a potential predictor or co-predictor for landscape and habitat studies – especially in urban areas, where the negative effects of fragmentation might be much higher than in rural or more natural landscapes. Performing preliminary tests on comparisons between area and perimeter is highly recommended.     

Tritrophic association on dandelion in a European capital city: a pilot quantitative study on the herbivore weevil <Emphasis Type="Italic">Glocianus punctiger</Emphasis> and its parasitoid wasp <Emphasis Type="Italic">Entedon costalis</Emphasis>

This study is a first attempt to estimate the degree of tritrophic association between the common dandelion Taraxacum officinale complex, the herbivorous weevil Glocianus punctiger and its parasitoid Entedon costalis, as an environmental marker in urban ecosystems. The study was conducted on 3926 dandelion flowering stems spread across 24 sample plots situated within the municipal borders of Kyiv (Ukraine). Eighteen plots were infested by the weevils, and 14 plots were infested by E. costalis. Of all the examined dandelion stems, 359 (9.1 %) were infested by weevils, and 21.4 % of these weevil-infested stems were parasitized by E. costalis. Thirty-two incidents of superparasitism were registered in nine sample plots. Seven environmental variables were chosen for characterization of the sample plots and for testing their possible effects on the tritrophic association. The results indicate that the infestation of dandelions by weevils is strongly limited by the grasslands’ mowing. Apart from that, the presence of anthropogenic barriers bounding the study areas negatively affected the parasitism of G. punctiger by E. costalis. This is regarded as an example of the crucial effect of habitat fragmentation on the specialist herbivore and the specialist parasitoid of this tritrophic system. Both the mowing and habitat fragmentation are linked with human land-use regimes on the sample plots.     

Ecosystem services assessment of the urban forests of Addis Ababa,Ethiopia

Addis Ababa is a highland city with varied topography and landscape features. The mountains that surround the city are covered with urban forest of different types. These forests are providing various ecosystem services for the urban and peri-urban population of the city. Apart from surface temperature regulating function of the green spaces of Addis Ababa, no quantitative assessment of the carbon sequestration and soil protection ecosystem services provided by the urban forest has been conducted to date. The aim of this study was to assess selected ecosystem services such as carbon storage potential, habitat support and soil erosion protection provided by different categories of urban forest of Addis Ababa. The result showed that carbon density in the study area varied with forest categories viz. 293tons/ha, 142tons/ha and 132tons/ha in the dense, medium and open forest types respectively. The Shannon-Wiener diversity index is3.24 for Junipers dominated forest, 2.98 for mixed forest and 2.76 for Eucalyptus dominated forest. The formation of soil erosion features is significantly different among the Eucalyptus forest, Juniperus forest and Mixed forest where high incidence of soil erosion was recorded in the Eucalyptus forest. Therefore, irrespective of the environmental factors such as slope, aspect and elevation differences, there is an association between Eucalyptus forest cover and high soil erosion features. To ensure sustainable supply of ecosystem services and maintain a balanced urban environment, all green spaces in the city should be ecologically networked and diversified. Therefore, assessment of ecosystem services provided essential information for effective planning of the green space in terms of species composition and interconnectivity.     

Influence of urban landscape structure on bird fauna: a case study across seasons in the city of Valencia (Spain)

Studies on bird fauna of urban environments have had a long history, but the potential of studies mapping the distribution of birds in cities probably has not fully developed. The bird fauna of the municipality of Valencia (Spain) was studied to determine the influence of urbanization on bird species richness and abundance. Birds were censused during winter and the breeding season of years 1997–1998 in 197 squares measuring 49 ha each from a rural and an urbanized area. Across seasons the number of species decreased around 40% in the city compared with the rural landscape surrounding it. Such pattern could be attributed to the low number of farmland species capable to use the habitats inside the city, and the limited ability of urban parks in attracting woodland species. In the urban landscape, the influence of the dimensions and spatial arrangement of habitat patches was outweighed by the amount of each habitat per square. Bird richness and the abundance of most species were negatively related with the amount of built-up habitat per square and positively with the amount of urban parks, and of habitat diversity. Conversely, bird fauna was largely independent of mean park size per square especially during winter, indicating that at the landscape scale even small patches of habitat could play an ecological role. Conservation of urban bird diversity could benefit of two complementary strategies: (i) the protection of the surrounding rural landscape from urban development; (ii) habitat enhancement within the city. Particularly, a proper design and habitat management of urban parks could improve their suitability for urban bird fauna.     

Variability of bumblebee communities (Apidae,Bombini) in urban green areas

Based on current research the agglomerations are potentially desirable habitats for bumblebees. However, the relationship between the biodiversity of these bees and the green areas where they live is poorly understood. The aim of the study was to estimate the influence of green areas (ranging from 8 to 102 ha) of big cities on bumblebee species richness, composition, and the relative number of these insects. The studies were conducted within the administrative borders of the city of Wroc?aw (Poland) in 2011–2012 in 12 green areas such as parks, cemeteries and other places with trees and shrubs. Species richness and abundance of bumblebees was determined by direct observation during 30 min. The gathered materials were used to calculate how areas of urban green space affected qualitative and quantitative bumblebee community structure. In total, 13 species of bumblebees (Bombus Latr.) were recorded, of which 3 belonged to cuckoo bumblebees (Psithyrus subgenus). The share of the most similar groups was congregated in green areas not smaller than 30 ha. This was proved by analysis of qualitative structure (Sørensen index), quantitative structure (Renkonen index), and qualitative-quantitative structure (Cody’s index). The number of bumblebee species in the surveyed green areas (r = 0.7497) was decisive for the arrangement of the mutual similarity of group structure. Green urban areas should be created in a size of at least 30 ha. Such sites provide conditions for the most diversified bumblebee species communities. Sites smaller than 30 ha can play an important role as refuges, and allow migration to all pollinators.     

Habitat type,food resources,noise and light pollution explain the species composition,abundance and stability of a winter bird assemblage in an urban environment

At present, urban areas cover almost 3% of the Earth’s terrestrial area, and this proportion is constantly increasing. Although urbanization leads to a decline in biodiversity, at the same time it creates extensive habitats that are exploited by an assemblage of organisms, including birds. The species composition and density of birds nesting in towns and cities are determined by the types of buildings, the structure and maturity of urban greenery, and habitat diversity. In contrast, the habitat traits shaping the community of birds wintering in urban areas are not known. The aim of this work was to assess the influence of habitat structure, food resources and the urban effects (pollution, noise, artificial light) on an assemblage of birds overwintering in an urban area. It was carried out in 2014 and 2015 in the city of Kraków (southern Poland), on 56 randomly chosen sample plots, in which the composition, density and interseasonal similarity of bird assemblage were assessed with line transect method. A total of 64 bird species (mean = 17.7 ± 4.9 SD species/plot) was recorded. The mean density was 89.6 ind./km ±63.3 SD. The most numerous species were Great Tit Parus major, Magpie Pica pica, Blackbird Turdus merula, Blue Tit Cyanistes caeruleus, Rook Corvus frugilegus, Fieldfare Turdus pilaris and House Sparrow Passer domesticus. Noise adversely affected species numbers and density, but artificial light acted positively on the density of birds and their interseasonal stability. The species richness and density of birds were also determined by the number of food sources available (e.g. bird-feeders). In addition, the greater the proportion of open areas, the fewer species were recorded. In contrast, the more urban greenery there was, the greater the density of the entire bird assemblage. Urban infrastructure (buildings, roads, refuse tips) had a positive effect on the interseasonal stabilization of the species composition of wintering birds. The results of this work indicate that the urban effect, i.e. noise and light pollution, apart from purely habitat factors, provide a good explanation for the species richness, density and stability of bird assemblage wintering in urban areas.     

Influence of urbanization on the occurrence and activity of aerial insectivorous bats

Activity and species-specific responses of insectivorous bats in different urban-forest conditions provides a general perspective on the adaptability and vulnerability of bat species towards urbanization intensity. Here we evaluated species richness and activity patterns of aerial insectivorous bats across an urbanized landscape in the highlands of Chiapas, in Mexico. Acoustic monitoring of echolocation calls was conducted for 27 nights over a period of four months. Species richness and relative activity of insectivorous bats were estimated in a landscape with different conditions of urbanization intensity: urban areas, non-urban and forest areas. We identified a total of 14 bat species and three phonotypes. Bat species richness and relative activity was similar (X² = 0.568, gl = 2, p > 0.05), but species composition differed among conditions. We observed a significant higher occurrence of Bauerus dubiaquercus, Eptesicus brasiliensis and Myotis californicus in forest sites. Urban sites presented higher occurrence of Molossus rufus and phonotype Molossidae 2, while non-urban sites presented a higher occurrence of Eptesicus furinalis and phonotype Molossidae 2. We were able to identify bat species according to their relative activity in relation todifferent landscape conditions. Species of the Molossidae family presented the highest activity in urban sites, which was positively affected by the number of streetlights, while species of the Vespertilionidae presented the highest activity in forest sites, which was positively related totree density. While urbanization tends to diminish native biodiversity and alter faunal communities, our results show a similar richness and relative activity of aerial insectivorous bats along the urban ecosystem. The effect of urbanization intensity becomes more apparent in species-specific bat activity; the response of species towards particular habitat conditions depends on local habitat quality and characteristics (i.e., presence of streetlights, vegetation cover and tree density).     

Persistence and survival of the spider <Emphasis Type="Italic">Nephila plumipes</Emphasis> in cities: do increased prey resources drive the success of an urban exploiter?

Species that successfully inhabit urban ecosystems are rare, and urbanisation often drives localised extinctions of native species. Nonetheless, some species take advantage of the novel conditions available in cities and increase in abundance. Trends in the abundance and distribution of species in urban areas have received much attention, but the precise elements of urban ecosystems that affect the survival of urban-dwelling species are largely unknown. Animals that successfully exploit urban environments may do so because of increases in the availability of resources or habitats. Here we assess the effects of anthropogenic landscapes and prey abundance on the persistence of an orb-weaving spider, Nephila plumipes. We assessed spider persistence for six months in situ along an urban gradient in Sydney. We then transplanted spiders from a common garden into sites along the gradient, monitored their persistence in the new environment and measured a suite of environmental variables at local and landscape scales. The abundance of prey was closely linked with spider persistence, in both the survey and the transplant experiment, and was positively associated with anthropogenic habitats. The surveyed spiders survived longer when located closer to the coast and transplanted spiders persisted longer in smaller sites with more impervious surfaces and reduced vegetation cover. Our study shows that urbanisation has a strong effect on potential prey abundance and can lead to increased persistence of N. plumipes, demonstrating the broad impacts that habitat disturbance can have on the life history and trophic interactions of city-dwelling animals.     

I’m not like everybody else: urbanization factors shaping spatial distribution of native and invasive ants are species-specific

Urbanization is a major global change inducing complex and multiple modifications of landscapes and ecosystems. The spatial distributions of organisms experiencing these modifications will likely shift specifically, depending on each species’ response to each environmental modification induced by urbanization. We sampled two ant genera (Lasius and Tetramorium) at 1248 locations along an urbanization gradient in Lyon, France and used high resolution spatial layers for 18 spatial (e.g., open habitat fragmentation, bioclimatic data and surface temperatures) and temporal (e.g., comparison of Normalized Difference Vegetation Index between 1986 and 2015) environmental variables associated with urbanization. Coupling two different analytical methods (Outlying Mean Index and Boosted Regression Trees), we showed that each species’ distribution was influenced by its own combination of environmental factors. Two morphologically cryptic Tetramorium species (T. sp.E and T. sp.U2) were both highly abundant but with opposite responses to urbanization: while T. sp.E was favored by urbanized habitat, T. sp.U2 avoided urbanized areas. Among Lasius species, we detected 63 occurrences of the invasive ant Lasius neglectus, the distribution of which was favored only by embankments along roads. We found that, even at this reduced spatial scale, climatic effects influenced most species and interacted with urbanization factors.     

Partitioning the effects of habitat fragmentation on rodent species richness in an urban landscape

Habitat fragmentation plays a major role in species extinction around the globe. Previous research has determined that species richness in fragments is affected by a number of characteristics. These include fragment age, size, and isolation, edge effects, vegetation coverage, habitat heterogeneity, and matrix content. Although most studies focused on one or a few of these characteristics, multiple characteristics work together to affect species richness, showing that the effects of habitat fragmentation are complex. The goal of our study was to partition the complex effects of habitat fragmentation by determining the direct, indirect, and cumulative effects of multiple habitat fragment characteristics on rodent species richness. In 2013, we determined rodent species richness in 25 habitat fragments within Thousand Oaks, California. In addition, we measured the following characteristics for each fragment: fragment age, area, isolation, shrub coverage, habitat heterogeneity, perimeter/area ratio, and percent non-urban buffer. Path Analysis was used to test the hypothesized model which described the direct, indirect, and cumulative effect of each habitat fragment characteristic on rodent species richness. Overall, the path model explained 67 % of the variation in rodent species richness among habitat fragments. Habitat heterogeneity had the greatest direct and total effect on rodent species richness. Fragment size had the next greatest total effect on rodent species richness but this was nearly entirely indirect through its influence on habitat heterogeneity, suggesting that large fragments containing the greatest diversity of habitats will support the most species. Our study shows that large habitat fragments support the greatest habitat diversity, which provides the highest likelihood of conserving rodent species richness in an urban landscape.     

Nest predators,but not nest survival,differ between adjacent urban habitats

Growing human populations make it imperative for ecologists to identify strategies to conserve biodiversity in human-dominated landscapes, such as cities. Effects of urbanization on birds are particularly well-studied, but questions remain regarding the best conservation approaches. Debate about the relative utility of focusing conservation efforts on nature reserves versus developed lands has focused largely on comparing species abundance or presence, with few studies addressing underlying behavioral or demographic mechanisms. Here we evaluated differences in avian reproductive success in nature reserves and matrix habitats to test the assumption that nest predation is lower within areas protected from development. Specifically, we investigated 1) whether nest survival differed in replicated pairs of forest parks and residential neighborhoods and 2) whether differences in nest survival were associated with changes in which species most frequently depredated nests. From April–August 2007–2014, we monitored nests of two native birds, American robin (Turdus migratorius) and northern cardinal (Cardinalis cardinalis), and video-documented nest predators in paired forest-matrix habitats in the Columbus, Ohio metropolitan area. We found similar rates of nest survival in the two habitats for both robins (Χ²₁?=?0.715, p?=?0.398, n?=?741 nests) and cardinals (Χ²₁?=?0.926, p?=?0.336, n?=?1156 nests), but interactions between predators and prey differed. In particular, domestic cats (Felis catus) were over five times as likely to depredate cardinal nests in matrix habitats versus forest parks (Χ²₁?=?7.24, simulated p?=?0.010; n_forest?=?3, n_matrix?=?7). Our results suggest that at least in some circumstances, nest success of native birds may be equivalent between nature reserves and adjacent residential matrix habitats, and thus residential neighborhoods may contribute positively to bird conservation in urban landscapes.     

Richness, composition and trophic niche of stingless bee assemblages in urban forest remnants

Few studies directly address the consequences of habitat fragmentation for pollinating insect communities, particularly for the neotropical key pollinator group of stingless bees. Most studies on bees have defined habitat fragments as remnant patches of floral hosts or forests, overlooking the nesting needs of bees. Their conclusion is that habitat fragmentation is broadly deleterious; however, there are contrasting results in the literature. Insightful studies on habitat fragmentation and bees should consider fragmentation, alteration and loss of nesting habitats—not just patches of forage plants –, as well as the permeability of the surrounding matrix to interpatch movement. Here we investigated the effects of fragmentation caused by urbanization on stingless bee species’ composition and richness, as well as the permeability of the surrounding matrix. We collected bees from flowering plants and recorded phytosociological variables of five forest remnants (ranging from 64 ha to 900 ha) in southeastern Brazil. Large fragments did not contain more species per unit area than smaller ones; in fact, we found more species in small fragments, most of which were generalist bees. The presence of more habitat generalist stingless bee species was also correlated to the structure of vegetation in these fragments. In conclusion, the quality of the habitat within a fragment (structure of vegetation) as well as the quality of the matrix has a direct relation to the bee species composition. This can be seen in the direct relationship between structural diversity of the environment and age of the fragments. The matrix that holds the most recent fragments, probably due to the sprawl of the city, is more heterogeneous than the one with the oldest fragments. The most heterogeneous matrices have a certain balance between the trees, buildings and bare soil or herbaceous vegetation coverage, making the array less impermeable to bees.     

Using macroinvertebrate assemblages and multiple stressors to infer urban stream system condition: a case study in the central US

Characterizing the impacts of hydrologic alterations, pollutants, and habitat degradation on macroinvertebrate species assemblages is of critical value for managers wishing to categorize stream ecosystem condition. A combination of approaches including trait-based metrics and traditional bioassessments provides greater information, particularly in anthropogenic stream ecosystems where traditional approaches can be confounded by variously interacting land use impacts. Macroinvertebrates were collected from two rural and three urban nested study sites in central Missouri, USA during the spring and fall seasons of 2011. Land use responses of conventional taxonomic and trait-based metrics were compared to streamflow indices, physical habitat metrics, and water quality indices. Results show that biotic index was significantly different (p?<?0.05) between sites with differences detected in 54 % of trait-based metrics. The most consistent response to urbanization was observed in size metrics, with significantly (p?<?0.05) fewer small bodied organisms. Increases in fine streambed sediment, decreased submerged woody rootmats, significantly higher winter Chloride concentrations, and decreased mean suspended sediment particle size in lower urban stream reaches also influenced macroinvertebrate assemblages. Riffle habitats in urban reaches contained 21 % more (p?=?0.03) multivoltine organisms, which was positively correlated to the magnitude of peak flows (r ²?=?0.91, p?=?0.012) suggesting that high flow events may serve as a disturbance in those areas. Results support the use of macroinvertebrate assemblages and multiple stressors to characterize urban stream system condition and highlight the need to better understand the complex interactions of trait-based metrics and anthropogenic aquatic ecosystem stressors.     

The influence of small urban parks characteristics on bird diversity: A case study of Petaling Jaya,Malaysia

The capacity of small urban park to serve as urban habitats are rarely explored. This study analyses the characteristics of small urban parks and their potential to support urban biodiversity and ecological functions. Nine small urban parks were studied in Malaysia in August and September 2014 using the combined field survey method of structured observation and field measurements. The measured variables were divided into three broad categories of physical characteristics, species richness and human factors. Bird species richness and abundance were used as the indicators for assessing biodiversity. Pearson correlations and multiple regressions were conducted to analyse the relationships between variables and to identify which variables had a significant effect on bird species richness and abundance. The results demonstrated that park area and vegetation variables ( e.g. the percentage of tree canopy cover, open grass/ground, native-exotic plants) are the important predictors of bird species richness and abundance. The percentage of canopy covers (negative relation) and park area (positive relation) are the best predictors of bird species richness in small urban parks. Meanwhile, the best predictors for bird abundance are the percentage of canopy covers (negative relation) and native vegetation species (positive relation). Human activities and park surroundings have a marginal effect on the presence of bird species in small parks. Based on the findings, we provide two general recommendations that could probably increase bird diversity in small urban parks: (1) the park development and management plan should incorporate a social-ecological approach that can benefit both city-dwellers and bird species, and (2) findings from the study should be used to rethink the planting design and composition of especially newly established small urban parks.     

Food in a row: urban trees offer valuable floral resources to pollinating insects

Urbanization affects the availability and diversity of floral resources (pollen and/or nectar) for wild pollinating insects. For example, urban green areas are characterized by an abundance of ornamental plant species. Increasingly, trees are planted to improve the aesthetics of urban streets and parks. These urban trees might offer important floral resources to pollinating insects. To examine the suitability of urban trees as resources for pollinating insects, we investigated the chemical composition of pollen and nectar as well as the amount of nectar produced by the nine major insect-pollinated tree species planted in cities of Western Europe, namely Acer pseudoplatanus, Aesculus carnea, A. hippocastanum, Robinia pseudoacacia, Tilia cordata, T. x euchlora, T. x europaea, T. platyphyllos and T. tomentosa. The analyses revealed that globally the Tilia trees provide pollen with lower contents of polypeptides, amino acids and phytosterols compared with the other species. Urban tree flowers offer abundant nectar with relatively high sugar contents (0.16–1.28 mg/flower); sucrose was the predominant sugar in all nectars. The investigated tree species could therefore be considered in future city plantings.     

Green remnants are hotspots for bat activity in a large Brazilian urban area

Urbanization tends to remove or isolate green areas into fragments or restrict them to narrow corridors inserted in a matrix of buildings. Nevertheless, urban green areas may act as refuges for fauna and bats are among the animals able to use such habitats. Using bioacoustics we investigated the influence of green areas on the activity of insectivorous bats in the metropolitan area of Recife, a conurbation of 4 million people in the Atlantic forest of Northeastern Brazil. Bat activity was statistically higher in green areas, based on calls (t?=?2.5298, p?=?0.0165), but not on feeding buzzes (t?=?1.8132, p?=?0.0817) or social calls (t?=??1.5551, p?=?0.1329). Several species were able to persist in an urban matrix and calls were classified into 16 sonotypes, belonging to five families (Emballonuridae, Molossidae, Noctilionidae, Phyllostomidae and Vespertilionidae). However, activity was significantly more associated with areas with vegetation, indicating that green remnants are hotspots for bat activity. Our results indicate that most insectivorous bats have a biased use of the urban landscape and the maintenance of urban green areas is essential to preserve them and the environmental services they provide.