Frugivory and habitat use by thrushes (Turdus spp.) in a suburban area in south Brazil

Thrushes (Turdus spp., Turdidae) are among the most common frugivorous birds in urban areas around the world, where they disperse the seeds of a variety of plant species. We studied the abundance, habitat use, foraging behavior and diet of four thrush species (Turdus rufiventris, T. amaurochalinus, T. leucomelas, and T. albicollis) in a suburban area in south Brazil. Abundance, habitat use and foraging behavior were based on birds surveyed along a 3,240 m transect crossing open (formed by lawns, streets, and buildings) and forested areas. Diet was based on fecal samples collected from mist-netted birds. Turdus rufiventris was the most abundant species, followed by T. amaurochalinus, T. leucomelas, and T. albicollis. All species used forest fragments more frequently than expected by chance. A total of 91.8% (n = 147) of the fecal samples contained fruit remains, while 42.2% contained only animal matter. Most of the foraging records were on the ground, where birds got mainly invertebrates. Fruits and invertebrates were eaten more frequently in open than in forested areas. A total of 25 seed morfospecies were found in the droppings, including five exotic plant species. Thrushes overlapped widely in the fruit composition of their diets. The high abundance and degree of frugivory, coupled with the frequent use of forest patches, indicate that thrushes are among the great bird contributors to the seed dispersal occurring in urban forest patches, potentially influencing the vegetation dynamics of such habitats so important for the maintenance of the biodiversity in urban areas.     

Carbon budgeting in golf course soils of Central Ohio

As global climate change (GCC) becomes an increasing societal concern, scientists are assessing soils’ capacity to sequester atmospheric CO₂ to off-set anthropogenic emissions. Therefore, this study was conducted to determine C sequestration potential in golf turfgrass systems in Central Ohio, USA, and to determine the effect of management practices on the net soil C sink capacity. Ohio farmland soils converted to golf course turfgrasses sequestered C at mean rates of 3.55 ± 0.08 Mg/ha/yr in fairways and 2.64 ± 0.06 Mg/ha/yr in rough areas. Soils in both fairway and rough areas sequestered C to 15 cm depth. However, hidden C costs of golf course development and management were also significant and major C emissions were attributed to diesel fuel combustion (6,557 kg Ce(Carbon Equivalents)/yr), unleaded fuel combustion (3,618 kg Ce/yr), N fertilizer use (1,498 kg Ce/yr), fungicide application (1,377 kg Ce/yr) and irrigation (626 kg Ce/yr), for an overall C emission of 14.15 Mg Ce per course per year (0.30 Mg C/ha/yr). Analysis of sequestration and emissions data showed that a newly constructed golf course has a technical C sequestration capacity of 2,224 Mg C over a 91.4 year period or the equivalent of 0.44 Mg C/ha/yr. However, the large C emissions generated by maintenance practices render courses from sinks to sources within 30 years. To maximize the potential environmental benefits of turfgrass systems while increasing the economic efficiency of each site, management practices with low C-intensity should be utilized.     

Effects of habitat fragment size and isolation on the density and genetics of urban red-backed salamanders (Plethodon cinereus)

Urban expansion is creating environmental stressors through land use change, habitat fragmentation, and habitat loss. These stressors, along with a host of others, are driving precipitous declines in vertebrate taxa around the world. Amphibians, often requiring a narrow range of environmental conditions, can be especially susceptible to the stressors of environmental change. Despite habitat loss and degradation, some amphibian species continue to persist in altered urban landscapes. The red-backed salamander (Plethodon cinereus) is one such- species and in this study, we assess how habitat patch size affects population density and genetic diversity of salamander populations in and around an urban center in Ohio, United States. Further, we examined patterns of genetic differentiation and landscape connectivity to understand gene flow between populations and tested for historic demographic bottleneck effects. Populations were sampled from 9 urban forest patches ranging in size from less than 1 ha to approximately 250 ha. There was no apparent effect of contiguous habitat patch size on salamander density nor genetic diversity, but we did observe significant genetic differentiation between 97% of pairwise population comparisons. The differentiation observed was not a result of overland distance or effective distance due to landscape resistance. There was evidence of historic bottlenecks at every site. These results suggest that density is driven by within-patch heterogeneity and that genetic diversity is affected by drivers other than patch size or contemporary population density. Our study demonstrates that red-backed salamanders can persist in wooded, urban parks, but that genetic diversity remains susceptible to demographic changes.

     

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.     

Impacts of traffic noise on anuran and bird communities

Anurans and birds rely on sound for a number of social behaviors. Species that use roadside habitats are exposed to traffic noise that can mask important social signals and directly affect the community diversity and composition. We evaluate the impact of traffic noise on anuran and bird species richness, species occurrence, and composition in Puerto Rico, where there is a high density of highways and cars that generate high levels of noise pollution. We compared paired forest sites near (100 m, n = 20, dB > 60) and far (>300 m, n = 20, dB < 60) from highways, with similar vegetation structure, but different levels of noise. We found that the anuran community was not affected by traffic noise. In contrast, bird species richness and occurrence were significantly lower in sites near the highway, and bird species composition also varied significantly. Bird species with low-frequency songs were only detected in sites far from highways. The differences in the ecology and communication behavior between anurans and birds could explain these results. Anurans mainly call at night, when traffic activity was low. In contrast, bird singing activity occurs during the day and overlaps with the high levels of traffic noise. In addition, in natural habitats, Puerto Rican anurans occur at high densities and form noisy choruses (>80 dB), which may allow them to tolerate high levels of anthropogenic noise.     

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.     

Use of urban marine habitats by foraging wading birds

Wading birds (i.e, Ardeidae: herons, egrets, and bitterns) are a guild of waterbirds that forage in coastal habitats which in the US and Europe are often located in close proximity to urban centers. However, the use of urban marine habitats may have consequences for bird populations, as birds can be subject to stress from increased levels of passive and active human disturbance. We examined the effects of human disturbance, available foraging habitat, and prey abundance on wading bird density and species richness at 17 urban coastal sites in Narragansett Bay, Rhode Island USA. The sites represented a gradient of immediately adjacent residential and commercial land use (e.g., 0.0–67.7% urban land use within a 30.5 m buffer of the sites) within an urban matrix (i.e., all sites were located within a suburban center with a population of about 85,000 people). Wading bird density (0.62 ± 0.12 birds ha⁻¹) and species richness (average 4.49 ± 0.37 species across all sites) were not influenced by passive human disturbance as measured by the extent of urban land surrounding a site. However, wading bird density and species richness both decreased significantly as active disturbance (i.e., number of boats moored or docked upstream of the site) increased (r = −0.56, F = 6.85, p = 0.019 and r = −0.73, F = 16.6, p = 0.001, respectively). In addition, both density (r = 0.72, F = 16.2, p = 0.001) and species richness (r = 0.72, F = 16.2, p = 0.001) increased concomitantly with a prey index that combines the density of fish and invertebrates on which the birds feed with the amount of available shallow water foraging habitat at a site. Our results suggest that wading birds i) may not be negatively affected by urban land surrounding estuarine foraging areas in and of itself; and ii) may be utilizing urban areas in the absence of high levels of active disturbance to take advantage of potentially enhanced prey resources. In the case where the benefits of foraging at a site outweigh the costs related to human disturbance, urban marine habitats may need to be considered for restoration or protection from further increases in active human disturbance.     

Salinization alters ecosystem structure in urban stormwater detention ponds

Stormwater ponds now comprise a significant portion of standing water in urban areas. These ponds act to sequester excess run-off and pollutants, such as road salt deicers. While these man-made ponds are not intended to serve as freshwater ecosystems, it is becoming clear that they do provide habitat for many organisms, but we know little of their ecosystem structure, function and interactions with pollutants. From April through June 2009, we surveyed 8 stormwater ponds in the Red Run Watershed, Baltimore County, Maryland, USA to describe patterns in aquatic food webs associated with a gradient in road salt inputs. Periphyton, phytoplankton and zooplankton samples were collected from each pond every 4–6 weeks. Specific conductance, a measure of chloride salt loading, among the 8 ponds varied widely throughout the survey, ranging from 99 μS cm⁻¹ to 19,320 μS cm⁻¹. Low (average = 404 +/− 82.6 (SE) μS cm⁻¹) and medium (average = 1749 +/− 267 (SE) μS cm⁻¹) conductance ponds had lower algal biomass and higher densities of zooplankton taxa relative to high (average = 7231 +/− 2143 (SE) μS cm⁻¹) conductance ponds, which were largely devoid of all zooplankton through the end of May. The observed decline in zooplankton density along an increasing chloride gradient is consistent with experimental results of road deicer effects, suggesting algal resources are possibly freed from grazing pressure as zooplankton consumers are negatively impacted by road salt exposure. Our results highlight the potential for both direct and indirect effects of road deicers on freshwater communities.     

Spatial patterns of female Ailanthus altissima across an urban-to-rural land use gradient

Ailanthus altissima is an invasive, dioecious deciduous tree common at the interface between urban and rural areas in the mid-Atlantic region, U.S.A. To examine spatial patterns of abundance and associations with land use type, we mapped all mature female trees in nine 89.5 ha plots (805.5 ha total area) across a typical urban-to-rural land use gradient using aerial images obtained via remote sensing supplemented by detailed ground referencing. Rural plots were dominated by forest and had the lowest density of mature females (0.007 females ha⁻¹); urban and suburban plots did not differ significantly in mean density (0.37 females ha⁻¹ vs. 0.34 females ha⁻¹, respectively). Individuals in urban plots were more evenly distributed, but were not associated with a wider variety of land uses and were closer to roads or openings than those in suburban plots. Given less available habitat per unit area in urban than in suburban environments, these patterns suggest that Ailanthus fits the profile of an invasive species that may be proliferating outward from urban centers. With continued disturbances associated with development in the suburban areas, and timber harvesting in the rural areas, further spread of Ailanthus seems likely.     

Relative importance of habitat quantity, structure, and spatial pattern to birds in urbanizing environments

Urbanization reduces the quantity of native vegetation and alters its local structure and regional spatial pattern. These changes cause local extirpations of bird species associated with native vegetation and increases in the abundance and number of bird species associated with human activity. We used 54–1 km² landscapes in the Seattle, Washington, USA metropolitan area to determine (1) the relative importance of habitat quantity, structure, and pattern to bird diversity and abundance and (2) whether housing developments can be managed to mitigate the negative impacts of urbanization on forest bird diversity. In general, bird species richness was high and many native forest species were retained where urban landcover comprised less than 52% of the landscape, tree density (especially that of evergreens) remained at least 9.8 trees/ha in developments, and forest was at least 64% aggregated across the landscape. These results suggest that the quantity, structure, and pattern of forested habitat affected breeding bird diversity in urbanizing landscapes. However, habitat pattern appeared less influential than other habitat attributes when results from all community- and population-level analyses were considered. Conservation of native birds in reserves can be supplemented by managing the amount, composition, structural complexity, and—to a lesser extent—arrangement of vegetation in neighborhoods.     

Ecological consequences of fragmentation and deforestation in an urban landscape: a case study

Landscape change is an ongoing process even within established urban landscapes. Yet, analyses of fragmentation and deforestation have focused primarily on the conversion of non-urban to urban landscapes in rural landscapes and ignored urban landscapes. To determine the ecological effects of continued urbanization in urban landscapes, tree-covered patches were mapped in the Gwynns Falls watershed (17158.6?ha) in Maryland for 1994 and 1999 to document fragmentation, deforestation, and reforestation. The watershed was divided into lower (urban core), middle (older suburbs), and upper (recent suburbs) subsections. Over the entire watershed a net of 264.5 of 4855.5?ha of tree-covered patches were converted to urban land use??125 new tree-covered patches were added through fragmentation, 4 were added through reforestation, 43 were lost through deforestation, and 7 were combined with an adjacent patch. In addition, 180 patches were reduced in size. In the urban core, deforestation continued with conversion to commercial land use. Because of the lack of vegetation, commercial land uses are problematic for both species conservation and derived ecosystem benefits. In the lower subsection, shape complexity increased for tree-covered patches less than 10?ha. Changes in shape resulted from canopy expansion, planted materials, and reforestation of vacant sites. In the middle and upper subsections, the shape index value for tree-covered patches decreased, indicating simplification. Density analyses of the subsections showed no change with respect to patch densities but pointed out the importance of small patches (??5?ha) as ??stepping stone?? to link large patches (e.g., >100?ha). Using an urban forest effect model, we estimated, for the entire watershed, total carbon loss and pollution removal, from 1994 to 1999, to be 14,235,889.2?kg and 13,011.4?kg, respectively due to urban land-use conversions.     

Chemistry of growth medium and leachate from green roof systems in south-central Texas

Installation of intensive and extensive green roofs is becoming popular for reducing runoff from impervious surfaces in many cities around the world. Most studies on runoff quality from green roofs have been conducted in cooler northern climates. We examined the losses and gains of nutrients, cations and selected anions in planted and unplanted growth medium and compared these to initial growth medium (IGM) typically used for green roof modules in south-central Texas. Water extracts of growth medium and leachate from three replicates of unplanted growth medium and three planted species (Sedum kamtschaticum, Delosperma cooperi and Talinum calycinum) were examined. During the first 6 months after establishment we observed high losses of nitrate (25 to 44 mg kg⁻¹), dissolved organic carbon (DOC: 155 to 190 mg kg⁻¹) and nitrogen (DON: 9.0 to 11.2 mg kg⁻¹) and orthophosphate-P (1 to 2 mg kg⁻¹). Average leachate concentrations based on four rain events 6 months after establishment ranged from 0.3 to 6.6 mg L⁻¹ in planted modules and 6.3 mg L⁻¹ in unplanted modules for nitrate-N, 38 to 42 mg L⁻¹ in planted modules and 32 mg L⁻¹ in unplanted modules for DOC, 2.1 to 3.1 mg L⁻¹ in planted modules and 2.1 mg L⁻¹ in unplanted modules for DON and 0.27 to 0.37 mg L⁻¹ in planted modules and 0.40 mg L⁻¹ in unplanted modules for orthophosphate-P. We suggest that after the establishment of green roofs, leachate losses may contribute some runoff concentrations of nitrogen, carbon and phosphorous in urban areas.     

Reproduction, juvenile survival and retention in an urban fox squirrel population

Fox squirrels in an urban environment had an average litter size of 2.83 (95% CI 2.5, 3.16) which was similar to rural populations. Nonetheless, the proportion of squirrels reproductively active during the summer/fall breeding season (0.73) and annually (spring + summer/fall) was higher (1.23) than previously recorded for non-manipulated rural populations. The average monthly survival rate () of urban juvenile fox squirrels during the first 14 weeks of life was higher than reported for adult populations in the area. High rates of reproduction and juvenile survival yielded high juvenile to adult ratios (juveniles/adults) averaging 0.44. Retention of juveniles after 6 months (15%) was significantly less (χ ² = 7.24, p = 0.0071) than adults/subadults (40%). Results suggest that the urban environment provides quality habitat for fox squirrels and fox squirrels in urban environments have the potential to be a source population for surrounding suburban and rural environments.     

Land-use planning to conserve habitat for area-sensitive forest birds

Models predicting the occurrence of area-sensitive bird species in forests were developed from bird survey data from 499 forests in Prince George's County, Maryland. The predicted probabilities of occurrence for species were integrated with forest cover data for the County in a Geographic Information System (GIS). This information was used in combination with local zoning and forest conservation requirements to develop a preliminary forest conservation plan for the watershed of the Western Branch of the Patuxent River. We identify forests patches most likely to support breeding populations of area-sensitive birds, and use the GIS to devise ways to consolidate and link them. Forests that do not contribute significantly to the integrity of these priority forests are designated as sites in which development could occur. The resulting conservation plan will maintain and enhance breeding habitat for area-sensitive forest birds, while still allowing for additional development as human populations increase.     

Toward increasing avian diversity: urban wildscapes programs

Residential development in urban and suburban settings is a major cause of habitat change affecting avian communities. The effects from land-clearing prior to initiation of construction followed by landscaping focused on traditional aesthetics has reduced habitat diversity at multiple levels. These residential developments generally emphasize the use of ornamental, nonindigenous vegetation with little to no concern for native species and natural vegetation parameters. As a result, avian community composition and diversity is changed. We compared avian communities at three sites in Bexar County, Texas; two residential neighborhoods in the city of San Antonio and an unincorporated undeveloped site, Government Canyon State Natural Area. The residential neighborhoods were a Texas Parks and Wildlife Department certified wildscapes development and a traditionally developed neighborhood. Bird abundance and species richness in the neighborhoods were greater than at Government Canyon State Natural Area (P < 0.01), but no differences existed between the neighborhoods. Bird diversity was greatest at the wildscapes neighborhood (P < 0.01). Further, bird diversity did not differ between the traditional neighborhood and the natural area. Evenness differed among sites (P = 0.006) with the natural area having the greatest value. Bird diversity measures correlated with woody plant density and vertical cover (r = 0.358 to 0.673, P < 0.05) at residential sites. Residential areas incorporating natural landscapes into their design attracted a greater variety of birds than traditionally landscaped residential areas.     

Avian population dynamics and human induced change in an urban environment

The predominantly urban boroughs of Warrington and Halton straddle the river Mersey in northwest England. Since the 1970s there has been a major change in land-use associated with both innovative town design and the decline of manufacturing and chemical industries in the boroughs. Also, co-ordinated programmes have directly addressed air and water pollution. The breeding birds of the two boroughs were surveyed in 1978–84 and 2004–06 as part of the bird atlases of Cheshire and Wirral, based on tetrads (2 × 2 km squares). We divided the breeding species into eight guilds based on broad ecological characteristics of habitat or food, omitting the generalists and colonial species, and compared the change between our two atlases in the number of occupied tetrads in Halton and Warrington and in the rest of the county. Four of our eight guilds have fared significantly better within our study area: waterbirds (24 species), those feeding on invertebrates (16 species), woodland specialists (21 species) and the two species that decorate their nests with lichens. The remaining four guilds showed no difference between Halton and Warrington and the rest of Cheshire and Wirral: raptors (5 species) have increased throughout, while breeding waders (7 species), farmland seedeaters (7 species) and aerial insectivores (5 species) have declined throughout. We interpret these results in relation to improved quality of water and air and changing patterns of land-use in the urban greenspace, especially an increase in woodland cover and connectivity.     

Connectivity of public urban grasslands: implications for grassland conservation and restoration in cities

An important limitation of studies on the ecological value of urban habitats is the question of habitat connectivity. While connectivity allows spread and genetic exchange of species, isolation can lead to the extinction of populations through inbreeding and loss of genetic diversity. However, while practitioners already start improving urban habitat patches by means of restoration, issues of connectivity have not been taken in account although being crucial for a self-sustaining habitat network. In our study, we evaluate the connectivity of public urban grasslands such as lawns, grasslands in residential areas, playgrounds or parks in the city of Münster, Germany. Employing a graph theory approach, which uses a map (graph) of habitat patches to calculate functional connectivity measures using patch area size and patch connectivity, we studied four groups of different plant dispersal distances (2 m, 20 m, 44 m and 100 m). This approach can be recommended for planning issues due to the output of different indicator values and comparably low data demands. Our results show for the first time, that connectivity of urban grasslands is extremely low for species of short-distance dispersal but slightly increases for long-distance dispersal. Except two larger conglomerations of well-connected patches, urban grasslands were found to be mostly sparsely connected. Thus, future research should focus on options to improve connectivity and to prioritize patches for ecological improvement. The graph theory approach turned out to be a useful tool to analyse urban habitat connectivity but also to illustrate results obtained.

     

Serum oxidizability potential is associated with age and exercise test results

The purpose of this paper is to find out whether serum oxidizability potential measured before an exercise test (EXT) correlates with age and ischemic heart disease severity. Oxidizability potential was determined in 3 age groups, in gr. I patients < 45 years, in gr. II age range = 45 - 70years {\hbox{range}} = {45} - {7}0{\hbox{years}} , and in gr. III patients > 70 years. Included subjects had chronic ischemic heart disease (IHD) and underwent a symptom-limited EXT upon initiation of a cardiac rehabilitation program. The thermo-chemiluminescence (TCL) assay was used to assess serum oxidizability potential. This assay is based on heat-induced oxidation of serum, leading to the formation of electronically excited species in the form of unstable carbonyls, which further decompose into stable carbonyls and light energy (low chemiluminescence). Measured photons emission is represented by a kinetic curve which is described by its amplitude and slope (=ratio). We assessed the correlations of TCL ratio with age, exercise duration, metabolic equivalents (METS), maximal heart rate (mHR), maximal systolic BP, >1 mm S-T depression, diabetes, hypertension, smoking, left ventricular ejection fraction (LVEF)> or <40%, previous myocardial infarction, and aorto-coronary bypass surgery. A high TCL ratio (%) correlated well with METS (r = 0.82), mHR (r = 0.77) and with exercise-induced S-T segment shift (r = 0.86, p < 0.05). A lower serum oxidizability potential, expressed as a low TCL ratio, thus suggestive of a previous high oxidative stress, was found in the two older age groups compared to gr. I (<45 years), p = 0.041, and in particular, in gr. III patients with low LVEF%. The TCL ratio (%) in gr. III was 188.7 ± 14.5, 192 ± 17 in gr. II, and 214 ± 13 in gr. I (p < 0.05), and was 166 ± 13.1 in gr. III with LVEF < 45% as compared to 271 ± 15.7 in gr. I patients with LVEF > 45% (p < 0.01). A trend for lower TCL ratio (%) was found in diabetic, hypertensive, and post-coronary bypass surgery patients. A paradoxically low TCL ratio (low oxidizability potential) was observed in patients without S-T depression compared to patients with S-T depression (189 ± 22 vs. 201 ± 15, p = NS), due to the fact these patients had a much lower LVEF% and a lower exercise capacity. Serum oxidizability potential is associated with age, EXT parameters, results, and IHD severity. TCL ratio is an “easy-to-measure marker” that might be incorporated into risk assessment and prediction in aged IHD patients.     

Relationships between urban parks and bird diversity in the Bangkok metropolitan area,Thailand

An analysis of the birds in Bangkok’s urban parks and landscapes provided guidance in designing healthy urban ecosystems. This research studied the relationships between bird diversity, park size, distance to the nearest main park, and habitat compositions in 10 urban parks in the Bangkok metropolitan area between January and August in 2013. Thirty sampling points per park were used to observe the number and species of birds in each urban park. A total of 50 bird species were found. Phutthamonthon, the largest urban park (400 ha), contained the greatest number of species (39 species), followed by Suan Luang Rama IX (80 ha and 34 species) and Wachirabenchatat (60 ha and 29 species). Moreover, the diversity index (H′) was highest in Phuttamonthon (1.17), followed by Thawiwanarom (1.08), and Wachirabenchatat (1.04). Larger urban parks and parks closer to the largest urban park had higher species richness than smaller parks and parks further from the largest urban park. The large parks contain higher habitat compositions than small parks. These findings can be applied to future urban ecosystem planning to combine the importance of park size (island size, and its proximity to a large park) and its arrangement, including features such as wetland, forest, buildings and grassland; and provide basic advice for future urban park design, as well as re-design of current urban parks.

     

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.