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1.
Urban Ecosystems - Traffic noise is known to negatively affect many wildlife species by interfering with foraging behavior. Frogs often lay their eggs in roadside ditches because they are...  相似文献   

2.
Forest bird communities across a gradient of urban development   总被引:1,自引:1,他引:0  
This study examined native bird communities in forest patches across a gradient of urbanization. We used field data and multivariate statistical techniques to examine the effects of landscape context, roads, traffic noise, and vegetation characteristics on bird community composition in the North Carolina Piedmont (U.S.A.). Landscape-level variables, particularly those related to urbanization, were most important in structuring forest bird communities. Specifically, we found that road density and amount of urban land cover were the best predictors of species composition. We found that urban and rural bird communities were quite distinct from each other. Rural communities had more long-distance migrants and forest interior species but species richness did not differ between the communities. Our results suggest some specific guidelines to target bird species of interest both inside and outside of urban areas. For example, if increasing numbers of migratory species is of primary concern, then conservation areas should be located outside of urban boundaries or in areas with low road density. However, if maximizing species richness is the focus, location of the conservation area may not be as important if the conservation area is surrounded by at least 50 m of forest habitat in all directions.  相似文献   

3.
We analyzed how urbanization in a desert ecosystem affects avian distribution at two distinct scales. At the regional level, we compared how urban land use configuration, relative to its surrounding agricultural fields and desert, affected the distribution of native and exotic species. While exotic species are isolated to the city; native species actively utilize the entire region, even occurring at higher densities in the city than in some areas of the desert. We also used this approach to compare four foraging guilds of birds: granivores, nectivores, omnivores, and insectivores. Granivores occurred mostly in agricultural fields and in the surrounding urban areas. Nectivores and omnivores occurred throughout the region, but mostly within the city. In contrast, insectivores occurred mostly in the desert. At a more local scale, we tested how the abundance of native species, exotics species and the foraging guilds of birds responded to vegetation cover measured at varying spatial scales (0.1 km–10 km). Bird guilds responded to vegetation at different scales, depending on the association between their life history and vegetation. Granivore abundance was most strongly correlated with vegetation at relatively fine spatial scales, followed by nectivores and omnivores at larger scales; whereas insectivores did not correlate with vegetation at any scale. Exotic and native species showed strikingly opposite trends in their association with vegetation. Native species showed the best fit at the smallest spatial scale and became insignificant at larger scales, whereas the highest correlation of exotic species with vegetation was at moderate to larger scales. While guild relationship with vegetation appears straightforward, the differences between exotic and native birds may indicate a complex response to environmental factors. Possibly, native species are more sensitive than exotics on vegetation abundance for food and shelter, which in the desert is highly variable depending on water availability. In contrast, exotic species, tightly connected to the urban infrastructure, likely respond to the enhanced and homogenized resource abundance characteristic of desert cities. Our results suggest that relationships between birds and vegetation may bear important information that can be revealed when considering smaller class levels than total species diversity.  相似文献   

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5.
This study investigated the impacts of urban wetlands and their adjacent residential environments on the transmission dynamics of West Nile virus (WNV) within the state of New Jersey (USA). A working hypothesis was that urban wetlands decrease the local prevalence of WNV through the dilution effect from increased bird diversity, and through relative reductions in the numbers of competent avian host and mosquito species commonly associated with WNV. Surveys of mosquito and bird communities were undertaken at six urban wetlands and their adjacent residential environments over two seasons (2009, 2010). The community compositions of both avian and mosquito species differed significantly across habitats, and over relatively short geographical distances. Residential areas contained significantly higher proportions of WNV-competent mosquito species (31.25?±?5.3?%; e.g. Culex pipiens and Culex restuans), and WNV-competent avian host species (62.8?±?2.3?%, e.g. House Sparrow and American Robin) when compared to adjacent urban wetlands (13.5?±?2.1?%; 35.4?±?2.1?% respectively). Correspondingly, WNV infection rates within local Culex spp. populations indicate that WNV was more prevalent within residential areas (28.53/1000) compared to wetlands (16.77/1000). Large urban wetlands (>100?ha) produced significantly lower weekly WNV infection rates in local Culex spp. (6.67?±?2.84/1000) compared to small (<15?ha) wetlands (22.57?±?6.23/1000). Avian species richness was also influenced by patch size. Large urban wetlands contained significantly more species than small wetland patches. These results confirm that the community compositions of mosquito and avian hosts are important drivers in WNV infections, and that the ecological conditions that favor transmission are more strongly associated with urban residential environments than with adjacent urban wetlands.  相似文献   

6.
Urban vacant lots can vary considerably in their vegetation structure, from dense, shrubby habitats to wooded remnant fragments that may provide habitat for a variety of birds. By identifying which features promote diverse bird communities, we can determine at which scale management practices should focus and the necessary habitat structure and composition features. We surveyed 150 vacant lots throughout Baltimore, Maryland for their bird communities, lot vegetation, and landscape-level forest cover. An ordination of the bird community indicated a response to a gradient of canopy cover and canopy height at the vacant lot. We also found that forest cover within 100 m of the vacant lot was the most important predictor of abundance for five bird species of interest. Species richness was spatially autocorrelated among sites, indicating that bird communities may also be driven by species’ dispersal and environmental gradients across the city. Overall, bird communities are responding to habitat features across multiple scales, from the vacant lot vegetation, to landscape-level forest cover, to city-wide dynamics. Thus, we recommend management practices to focus on increasing city-wide forest cover in order to increase species richness, yet with awareness regarding where the lot occurs within the city.  相似文献   

7.
The goals of the current study are (a) to understand the community and state context in which STOP(Services* Training* Officers* Prosecutors)-funded victim service (VS) programs operate, (b) to assess the degree to which receipt of STOP funding for VS programs and the degree of state-level STOP agency support for collaboration among community agencies have led to improved program services and community interaction, and (c) to assess the degree to which improved interaction between community agencies leads to improvements for VS programs. The results show that community interaction between VS programs and other community agencies can improve VS program services as reported by service providers. In addition, the higher the pre-STOP levels of activity around violence against women issues in communities, the more agencies can enhance their service system with STOP funding. Also, STOP funding has facilitated greater levels of change for communities whose pre-STOP attention to violence against women was lower.  相似文献   

8.
University campus is an important component of urban landscapes for biodiversity conservation. However, to our knowledge no study has quantitatively assessed the diversity and structure of bird communities in Chinese university campuses, especially from phylogenetic and functional perspectives. Here, for the first time we linked species richness, phylogenetic structure and body mass structure of campus bird communities with contemporary climate, glacial-interglacial climate change, altitudinal range, population density around campus, area and age of campus to test their associations. We found 393 bird species in 38 university campuses (29% of all Chinese bird species, two species are endangered, four species are vulnerable, and 33 species are near threatened). The variables significantly correlated with campus bird species richness, phylogenetic structure and body mass structure were altitudinal range and mean annual precipitation, glacial-interglacial anomaly in temperature, and altitudinal range, respectively. In particular, there were more species in steeper and wetter campuses, more young species clustered in campuses with stable glacial-interglacial climate, and more species with smaller body size in steeper campuses. Our study highlights the importance of considering both phylogenetic and functional information for biodiversity conservation in urban ecosystems.  相似文献   

9.
We evaluated the richness, composition and abundance of bird communities in three urban forests of Mediterranean France during winter and spring. The urban forests differed in size, composition, structure, age of vegetation, and location relative to the city centre. Estimated species richness across all three urban forest parks was 45 species. Twenty six (26) species were recorded in both winter and spring, whereas ten species were recorded only in spring, and six were recorded only in winter. Distribution, turnover, and type of bird foraging guild were related to characteristics of each urban forest and season. During spring migration, more species were recorded in sampling units (250?×?250 m) within the largest and most natural urban forest located in the outskirts of Montpellier, whereas during winter, more species were recorded in the most urbanized park (i.e., a botanical garden dominated by exotic vegetation), which was located in the city centre. Insectivorous birds were more abundant in winter, whereas seedeaters associated with wooded habitats were recorded more frequently in spring. Our results suggested that different kinds of urban forests are important modulators of urban bird communities and they are necessary to maintain the diversity of migratory and resident birds as well as increasing the environmental quality of urban areas.  相似文献   

10.
Breeding bird communities in Berlin were investigated at five study sites, which represent an structural urban-rural gradient, from densely built-up areas with sealed ground to green areas such as large parks. In this paper, we tested the Hasse Diagram Technique (HDT), an approach belonging to partial order theory, for its appropriateness to extract information about changes in species composition from our data set. As expected, the overall number of bird species was positively correlated with the urban-rural gradient, increasing from 12 found in the city center to 28 in an urban park. By HDT analysis, four different sub-groups of birds could be identified, contributing differentially to the increase in species number: (1) ubiquists, i.e., species found at each study site, (2) a sub-group, the species’ number of which was positively correlated with the urban-rural gradient, increasing with increasingly green areas, (3) a sub-group, the species’ number of which was negatively correlated with the urban-rural gradient, decreasing with a declining density of buildings, and (4) species, the distribution of which did not show any correlation with the urban-rural gradient. The results show that HDT is a suitable tool for formalized analysis of the pattern of species’ communities along an environmental gradient.  相似文献   

11.

High population growth in the tropics is driving urbanisation, removing diverse natural ecosystems. This is causing native species to suffer while introduced synanthropes flourish. City planners are developing urban greenspace networks, in part trying to address this issue. Architects contribute to these greenspace networks by designing elevated and ground level green spaces on large-scale buildings. However, little evidence is available on whether building green spaces support native fauna. This is true for birds in tropical Singapore that support important ecosystem services and have existence value. Therefore, in this study, we conducted bird surveys and statistical analyses to determine, if and how vegetation on three building green space types (ground gardens, roof gardens and green walls) have a positive impact on native or introduced bird species. We found that elevated greenery (roof gardens and green walls) on large-scale buildings supported a higher richness of birds and abundance of urban native birds than control roofs and walls without vegetation. Ground gardens supported similar levels of native species as roof gardens but also a larger proportion of generalist synanthropes. However, we found no tropical forest habitat specialists across any space type. Therefore, we recommend roof gardens and ground gardens as a potential space for urban natives outside of a less competitive ground-level urban environment. Our study also found certain building design elements (height of elevated space, presence of specific plants) supported different species groups. Therefore, we suggest that these ecological requirements for different species groups are considered when designing a building’s green space.

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12.
13.
Urban forest fragments can potentially be ‘habitat islands’ for native birds, but pedestrian traffic could influence the composition and conservation value of their bird assemblages by reducing the representation of disturbance-sensitive species. Winter bird assemblages and pedestrian traffic rates were documented in twelve forested parks in suburban Melbourne, Australia. Native birds comprised 87% of sightings, but two exotic species were common. Bird species' distribution among the parks was significantly nested. However, park rank orders for bird assemblage nestedness and mean pedestrian traffic rate were not correlated and only one species' distribution was nested with respect to this variable. The observed correlation between park area and bird assemblage nestedness may have been partly due to passive sampling. Degree of isolation of parks influenced nestedness less than park area. Forested parks provided habitat for species that occur at intermediate to low densities in other suburban habitats and for ecological specialists otherwise rare in suburbia. Larger parks contained more species than, and many of the native species found in, smaller parks. However, smaller parks each had 25% of the native bird species inhabiting the suite of fragments and thus had both aesthetic value and some potential to enhance city-dwellers' awareness about biodiversity conservation.  相似文献   

14.
The purpose of this study is to analyze the relationship between home modifications and aging-in-place. Using the ENABLE-AGE United Kingdom sample (N = 376), the authors hypothesize that seniors who have modified their housing are likely to have stayed longer in their current housing. There is a positive relationship between home modifications and aging-in-place. The results underscore the importance of supportive environment to prolong living in housing settings.  相似文献   

15.
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.  相似文献   

16.
梳理深圳新业态发展现状、特点、领域、趋势,前瞻性地研究新业态发展趋势以及驱动因素等,借鉴国内外新业态发展经验和启示,为推动新业态发展壮大提供决策建议。  相似文献   

17.
Urbanization is widespread throughout the United States and negatively affects many wildlife populations. However, certain urban features, such as retention ponds, may provide habitat for some species, such as amphibians. This study examines the influence of riparian zone proximity and pond age on retention pond occupancy by anurans. We identified and estimated the age of 25 retention ponds near Charlotte, North Carolina, USA and used a geographic information system to determine the distance to the nearest riparian zone. Occupancy modeling indicated that anuran presence decreased with increasing distance to riparian zone. Pond age also appeared to be an important factor, but the effect varied among species. Although the results of this study demonstrate the potential value of retention ponds to anurans, it is important to be conservative in estimating the ability of these ponds to sustain amphibian populations in urbanized regions.  相似文献   

18.
天津港城交通发展模式初探   总被引:1,自引:0,他引:1  
何枫鸣 《城市》2007,(5):50-52
一、港城交通存在的主要问题 (一)港城平行发展,争夺空间资源,港城发展相互制约 天津港作为滨海新区发展的核心战略资源,以彰显海滨特色作为新区的发展目标,长期以来港与城平行发展,缺乏有效分隔,在有限的空间里争夺资源,导致相互的空间挤压与影响.  相似文献   

19.
Abstract

Work on the determinants of alimony awards is sparse and often speculative. The present study tests the human capital and needs models of alimony with data from Alabama. The results of Tobit regression analyses provide mixed support for both theories. For example, the human capital model was supported for duration of marriage but not husband's education. The economic need model was supported for age of wife, but not her education or presence of children. While some indicators of both models are written into Alabama's Legal Code on divorce, most indicators of both models are not predictive of alimony awards in practice. Models of alimony should perhaps also look to consensual, normative factors rather than being constrained by those that find expression in legal codes.  相似文献   

20.
Estimating the relative importance of vegetation on residential land (gardens, yards, and street-trees) and vegetation on non-residential land (parks and other large green spaces) is important so that competing options for urban conservation planning can be prioritized. We used data from an urban breeding-bird monitoring program to compare the relative effects vegetation on residential land and vegetation on non-residential land (both the amount and type of vegetation at local and landscape scales) on bird species richness and an index of conservation value for the bird community. We then estimated the realised relative benefit of managing the amount of vegetation on these two types of land (i.e., as alternative management options for promoting biodiversity), which might be achieved within the practical limits imposed by human population density. The local effects of increasing residential and non-residential vegetation amount were similar and positive on all measures of bird species richness and conservation value. Non-residential vegetation had an additional landscape-scale influence on bird diversity that residential vegetation did not. Options for managing the amount of non-residential vegetation appear to be more limited by high human population density than for managing the amount of residential vegetation. This suggests that there may be greater realised benefits to bird diversity from managing the amount of vegetation on residential land than from the more common focus of urban planning of managing vegetation on non-residential land.  相似文献   

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