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1.
In urban areas the density of breeding tits (Paridae) is generally higher and reproductive performance lower compared to rural areas. To explain these landscape differences several hypotheses have been proposed, e.g. differences in habitat quality, inter- and intra-specific competition, predation and food abundance. How breeding performance of birds within remnants of natural vegetation in urban areas is affected by adjacent matrix has been less studied. We performed an experimental study in four urban woodlands surrounded by three types of habitat matrix: residential, high-rise building and grassland/golf course. We placed 300 nest boxes for tits (great tit Parus major and blue tit Cyanistes caeruleus) in 15 transects that were 200 m long, extending from the adjacent matrix 150 m into urban woodland. Density of breeding great tit pairs was highest in residential areas and hatch date was earlier in the residential habitat compared to the other two habitats, however, nestling condition was lower in residential areas. Hatching date was earlier but hatching spread (heaviest nestling/lightest nestling) higher in the three types of urban matrix than inside the urban woodlands. In contrast to previous large-scale comparisons of urban and rural matrix, we almost exclusively found differences in qualitative measures (nestling condition and hatchling spread) at the small scale in which this study was conducted. Adjacent matrix affect great tits breeding in remnant urban woodlands, thus we suggest that management of the surrounding matrix should be included in conservation plans for urban woodlands.  相似文献   

2.
Research has shown that family income's relations to early childhood achievement is stronger in large inner cities and weaker in less urbanized areas. Research has not yet considered whether links between family income and achievement in adolescence differ across the urban to rural landscape. Using nationally representative data from the Early Childhood Longitudinal Study, Kindergarten Class of 1998–1999 (N ≈ 9,350), this study examines differences in family income's links with eighth‐grade achievement across large urban, small urban, suburban, and rural communities. The point at which income‐achievement links plateau occurs later in the income distribution in less urbanized areas. The magnitude of the association between family income and reading and science skills also differs across the urban‐rural continuum, such that family income has stronger relations to reading and science achievement in urban cities and weaker links in suburban and rural communities.  相似文献   

3.

Raptors increasingly live and nest successfully in urban areas. In the urban landscape of Hartford, CT, red-tailed hawks established home ranges in large green spaces such as parks, golf courses, and cemeteries but also nested successfully in the commercial district of downtown and in densely built urban and suburban neighborhoods. Data collected from 11 radio-tagged breeding adult hawks indicated that year-round home ranges averaged 107.7 ha, much smaller than home ranges reported for hawks inhabiting rural areas. Most hawk home ranges had multiple core areas that were usually associated with favored perches or larger patches of ‘usable’ green space, defined as patches ≥0.25 ha in size, and home range size was positively associated with larger usable green space patches in core areas. Most nests were located in the largest core area and were within a larger patch of green space within the largest core area. Rather than just the amount or size of green space patches, the value of urban green spaces for these hawks likely also varies with the number and proximity of suitable perches such as buildings or tall trees, types and density of prey, and amount of human activity in and adjacent to these spaces. Territoriality and intraspecific competition may also influence home range size and dispersion of red-tailed hawks nesting in Hartford. In this urban area, mortality due to ingestion of rodenticides and collisions with vehicles affected hawk reproductive success.

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4.
Long- and short-term effects of urban site factors on net N-mineralization and nitrification rates were investigated in oak stands along an urban-rural land-use transect in the New York City metropolitan area. We used reciprocal transplants of undisturbed soil cores between urban and rural forests to determine the relative importance of long-term effects (mor vs. mull soils, quality of soil organic matter, and deposition of N) vs. short-term effects (soil temperature) of urban factors in controlling field N-transformation rates along the gradient. In addition, undisturbed soil cores from surface (A, Oe horizons) and subsurface (B horizon) soil were collected from urban, suburban, and rural stands and allowed to incubate in these respective sites to compare the net effect of all urban factors with transplanted-core results. The transplant experiment revealed that soil type (long-term) affected net N-mineralization and nitrification rates. Urban soils nitrified nearly 6.3 and 5.4 times more than rural soils incubating in urban and rural stands, respectively (p = 0.003 and p = 0.002, respectively). Similarly, in rural stands total accumulation of inorganic N was 87% higher in urban than in rural soils, whereas in urban stands, urban soils mineralized 83% more N than rural soils (p = 0.043 and 0.08, respectively). Comparing soils incubating in their native locations, urban soils incubating in urban stands mineralized more than 2.5 times the amount of N than rural soils incubating in the rural stands (p = 0.019). By contrast, urban soils incubating in urban stands exhibited a 8-fold increase in nitrification over rural soils incubating in rural stands (p = 0.008). As with the transplanted cores, the urban and suburban environments had a positive effect on net rates of N-mineralization and nitrification in both surface and subsurface layers of soil. The surface layer of suburban and urban stands had a 3- and 2.3-fold higher accumulation of net inorganic N than rural stands (ANOVA, p = 0.05). Similarly, in the subsurface layer both urban and suburban stands had 2.6-fold higher net N-mineralization rate than rural stands (ANOVA, p = 0.01). Along this urban-rural gradient, soils in oak stands exhibit higher net nitrification and, to a lesser extent, net N-mineralization rates in urban and suburban stands than in rural stands. Results from the transplant experiment and in situ measurements of surface and subsurface soil indicate that long-term effects (mor vs. mull soils, N deposition) contribute to the higher N-transformation rates in urban and suburban stands. As a result of these effects, urban and suburban stands have the potential for higher losses of N than rural stands.  相似文献   

5.
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.  相似文献   

6.
The aim of this study was to analyse the spatial distribution of vascular plants along a 21-kilometre rural–urban–rural transect in the city of Tampere, Finland. The study emphasised the distribution of native and non-native species, both in absolute numbers and proportionally. The observed differences are explained by the share of forest land, the number of detached houses, distance from the city centre, and human population. Non-natives showed the highest values in suburban areas. Still, the difference in number of non-natives between suburban and central areas was quite small. In the city of Tampere, there are not continuous large areas devoid of vegetation. The number of native species remained high until the urban core and natives dominated in the rural-type areas of the city. However, there was not a great difference in the number of native species between rural and suburban areas. In the suburban areas, the detached houses and block-of-flats have little effect on the general vegetation. Proportionally, the share of natives decreases in line with the urban traits of the city. Urbanisation therefore affects native species in Finland. Overall, the characteristic features of a Finnish city, such as dispersed urban structure, small population, late urbanisation, abundant natural vegetation (forest) and the qualities of Finnish forests, guarantee the continuing diversity of urban vascular plants.  相似文献   

7.
Most research involving lesbians has been conducted using urban or suburban samples. However, the challenges lesbians face in their rural communities differ from those encountered by lesbians in urban areas. Lesbians in rural areas face potential isolation due to the lack of a visible gay community, an overall lack of services and resources, and an often heightened experience of stigma. Rural areas tend to have a more conservative political climate with an emphasis on fundamentalist religious beliefs. Due to such strong heteronormist pressures, lesbians who decide to come out to their rural communities often face justifiable fears surrounding possible discrimination from employers, religious organizations, schools, and even their friends and family members. Therapists who work with lesbians in rural areas should be prepared to help their clients face and successfully deal with many unique challenges.  相似文献   

8.
Suburban landscape predominates within New Jersey; people live in one suburb and drive to a job in another. Research on community ideologies suggests, however, that even suburban residents have vague images of suburbs. Vague images can mean, in turn, that the state's visual artists produce few images that incorporate the newly‐created suburban landscape that they see every day. Research on art worlds also suggests little encouragement for work that depicts the newer suburbs. Consistent with this, only a few of the visual artists living in New Jersey who have put slides in three large slide files include work that deals with the newer suburban landscape or with the process of creating suburbs. Instead, artists who depict New Jersey landscape concentrate on the state's “natural” landscape or on the state's older industrial suburbs. The privacy of newer suburbs no doubt also contributes to this pattern. In suburbs, even places designed for crowds, such as retail malls, are private.  相似文献   

9.
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.  相似文献   

10.
Russo  Claudio  Young  Truman P. 《Urban Ecosystems》1997,1(3):171-178
Predation rates of natural and artificial bird nests in rural landscapes have been the subject of numerous studies, often in the context of proximity to edge. Similar studies in urban and suburban landscapes are lacking. We carried out a study of egg and seed removal at forest reserve edges in three urban and two suburban forests in and near New York City in 1994-1995. Few significant edge effects were found, but this may have been because of the extraordinarily high rates of egg and seed removal. Daily removal rates were higher in suburban sites (eggs, 86%; seeds, 95%) than in urban sites (eggs, 64%; seeds, 88%). Exposed seeds and eggs suffered higher rates of removal than seeds and eggs covered by leaf litter. Despite statistically significant differences among treatments, all of these rates would be prohibitively high if experienced by ground-nesting birds or large-seeded trees (if removal was associated with predation). A survey of the literature suggests that egg predation rates are prohibitively high in cities and peak in suburban sites (at least in this study), then drop rapidly in ex-urban and rural sites, perhaps because of a similar pattern in the abundance of corvid bird predators. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

11.
This study analyzes the movement of blacks to the suburbs of American metropolitan areas, using the framework developed by Taeuber and Taeuber (1965) for the analysis of racial transition in inner city neighborhoods. The data are consistent with their model and suggest that the rate of black population growth is a function not only of the characteristies of individual suburbs themselves, but also of the central cities of the metropolitan areas within which they are located. The units of analysis are all suburbs with populations of 10,000 or more in 1960 and 1970. Suburban size is a key characteristic because the independent variables affect black population growth quite differently in different size categories. While there are clear differences between southern and nonsouthern suburbs in average levels of the push and pull variables, as well as the rate at which the black suburban population grew in the 1960s, the effects of these variables on black suburban growth were the same in both regions.  相似文献   

12.
Recently researchers have made efforts to reconceptualize digital inequality into discrete levels. These levels reflect access to and diffusion of technologies, proficiency in Internet usage, and propensity to take advantage of the opportunities afforded by information and communication technologies for assistance in daily life. We assess the utility of this approach for studying digital inequality across rural, suburban, and urban counties. Based on data from a 2005 nationally representative random sample telephone survey of 2,185 adults, the results provide mixed support for using this approach to studying digital inequality. In particular, we find that rural residents use Internet technologies less for assistance in helping with economics and other daily activities when compared with individuals from suburban and urban areas; however, our results suggest that this relationship is the product of the slow diffusion of advanced technologies to rural areas. The implications of these findings for understanding this under‐theorized form of inequality are discussed, and we make contributions to this literature through empirically addressing issues of digital capital.  相似文献   

13.
With the continuing spread of urban areas, gaining a greater understanding of the effect of human presence on wildlife species is essential for wildlife managers. We determined the influence of anthropogenic resources on home range size and habitat selection of raccoons (Procyon lotor) during summer (June–August) 1996–2000 for 120 raccoons at three sites exposed to varying levels of urbanization and anthropogenic resources, specifically food. Home range estimates were larger (P < 0.05) at the rural site than the suburban and urban sites for both genders. We used compositional analysis to examine raccoon habitat selection at the second-order home range, second-order core area, and third-order home range scales. Woodland was consistently a highly-selected habitat type for both sexes at every spatial scale. Relative to other habitat types, habitat associated with human-related food (human use areas) was selected most often at the urban site, intermediately at the suburban site, and not selected at the rural site. Spatial scale also affected habitat selection. Human use areas were preferentially selected at the second- and third-order level at the urban site, third-order level only at the suburban site, and at neither level at the rural site. Additionally, intersexual differences in habitat selection were reduced at the urban site, with both sexes preferentially selecting for human use areas as well as woodland habitat. Smaller home ranges in urbanized environments are often attributed to the abundant and concentrated anthropogenic resources associated with human activity, but with little empirical support. Our habitat selection analyses followed our predictions that raccoon foraging is strongly influenced by the artificial distribution and abundance of human-related food. Male and female raccoons in urban areas reduce their foraging patterns and focus their foraging activity on anthropogenic foods.  相似文献   

14.
Two species of tree squirrel inhabit the Chicago region, the fox (Sciurus niger) and gray (S. caroliniensis) squirrel. Chicago residents submitted squirrel observations and associated landscape variables via a Website, allowing us to map squirrel distributions. Data were analyzed for patterns of correlation. At a smaller scale, we did a foot survey of fox and gray squirrels in the suburb of Oak Park, replicating an earlier study and comparing results. Gray squirrels were associated with densely populated areas, parks and campuses, fox squirrels with suburban areas. Compared to gray squirrels, fox squirrels were more likely to be observed in areas of high cat density. In the suburb of Oak Park, the current trend seems to be an extension of gray squirrel distribution and a decrease in fox squirrel distribution. Our study provides support for the idea that fox and gray squirrel coexistence is facilitated by a trade-off between managing the cost of predation and foraging efficiency, gray squirrels out-competing fox squirrels in areas of high food and low predator (or pet) density.  相似文献   

15.
The effects of highways on transforming human society and promoting population change have been investigated in several disciplines, including geography, sociology, economics, and planning. Currently, the primary highway construction activity in the nation is highway expansion; however, this expansion has not been the focus of much of the existing literature. This research examines the role that highway expansion plays in the process of population change. Specifically, this research proposes an integrated spatial regression approach to study the impacts of highway expansion on population change in the 1980s and 1990s in Wisconsin at the minor civil division level. The integrated approach thoroughly considers the factors that influence population change, appropriately examines the spatial variations of their impacts, simultaneously incorporates spatial lag and spatial error dependence, and systematically selects the optimal neighborhood structure. The findings suggest that the impacts of highway expansion on population change differ across rural, suburban, and urban areas: There are only indirect effects in rural areas, both direct and indirect effects in suburban areas, and no statistically significant effects in urban areas. Overall, highway expansion serves as a facilitator of population change within the framework of growth pole theory and location theory.  相似文献   

16.
Data collected out of the breeding season suggest that House sparrows (Passer domesticus) from the urban populations are characterized by a smaller body size and poorer body condition compared to birds from rural populations. Considering an urbanized Eurasian Sparrowhawk (Accipiter nisus) and other potential predators, a new predator-prey dependency is developing that can also be a reason for the House sparrow’s poorer condition. This study was aimed at comparing the multivariate biometrical characteristics and few body condition indices of adult birds from urban and rural populations during the breeding season. It was hypothesized that a higher predation risk during the breeding season concerns mainly males, thus affecting their poorer condition. Most of the condition indices of males were significantly lower in the urban population. Males from the urban populations had lower body mass, shorter tarsus, longer alula, greater Kipp’s distance and higher wing pointedness index in comparison to the birds from rural populations, whereas these differences were not found between females. We suggest that the lower body condition and biometric differences in the analyzed birds are a means of adapting to the new predator-prey scheme in accordance to the tradeoff theory between starvation and predation risks. A lower condition of birds in poor foraging urban habitats and higher predation risk may be indicative of a declining population.  相似文献   

17.

Urban environments present wildlife with major challenges and yet surprising numbers of species have colonised towns and cities globally. Despite the growing realisation that urban centres can be important habitats for wildlife, why some species do better than others in urban environments remains poorly understood. Here, we compare the breeding performance of an apex predator, the peregrine falcon (Falco peregrinus), in urban and rural environments, and test whether variation in reproductive success between and within environments is driven by prey. Historical breeding data were collected from raptor study groups across Great Britain between 2006 and 2016, from 22 urban and 58 rural nest sites, involving 101 and 326 nesting attempts, respectively. Prey density, biomass and diversity around the individual nests was estimated using modelled estimates from a national bird census. Urban peregrines produced more fledglings and had a higher overall nesting success (i.e. whether a nesting attempt was successful or unsuccessful) than rural peregrines. Prey density and biomass were significantly higher, and diversity significantly lower, in the urban sites, and explained the variation in reproductive success within both the urban and rural environments. Therefore, urban environments in Great Britain appear to provide peregrine falcons with superior habitats in terms of prey availability compared to rural habitats. We conclude that some apex predators can benefit from urban environments and that urban planning has the potential to benefit biodiversity across many trophic levels.

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18.
Changes in the relative status of central cities compared to their suburban rings are investigated for the periods 1920 to 1950, and 1950 to 1970. Longitudinal alterations in the relative statuses of the two components across metropolitan areas have primarily involved the suburban ring. Somewhat different processes of change were evident in the two time periods, particularly when metropolitan areas are distinguished by their age. In the 1920 to 1950 period, the oldest metropolitan areas evolved toward higher suburban than central city status, while newer metropolitan areas evolved toward higher central city than suburban status. In the 1950 to 1970 period, metropolitan areas generally moved toward a pattern of higher suburban than central city status, regardless of their individual characteristics such as age or period of development.  相似文献   

19.
Wildlife-human interactions are increasing in prevalence as urban sprawl continues to encroach into rural areas. Once considered to be unsuitable habitat for most wildlife species, urban/suburban areas now host an array of wildlife populations, many of which were previously restricted to rural or pristine habitats. The presence of some wildlife species in close proximity to dense human populations can create conflict, forcing resource managers to address issues relating to urban wildlife. However, evidence suggests that wildlife residing in urban areas may not exhibit the same life history traits as their rural counterparts because of adaptation to human-induced stresses. This creates difficulty for biologists or managers that must address problems associated with urban wildlife. Population control or mitigation efforts aimed at urban wildlife require detailed knowledge of the habits of wildlife populations in urban areas. This paper describes the history of wildlife in urban areas, provides examples of wildlife populations that have modified their behavior as an adaptation to urban stresses, and discusses the challenges that resource managers face when dealing with urban wildlife.  相似文献   

20.
Little is known about the environmental factors that limit the demography and abundance of wild vertebrates in highly modified urban environments. The House Sparrow Passer domesticus is a globally widespread species whose urban populations have recently undergone substantial declines particularly in Europe. The environmental drivers of these declines remain unknown. In a previous study we showed that invertebrate availability during the breeding season limited reproductive success but not population size in a suburban sparrow population. In this study we test experimentally whether year-round food availability limits demography and population size. Supplementary feeding involved the provision of invertebrate prey (during the breeding season) plus unlimited high-energy seed (year-round) at 33 sparrow colonies spread across suburban London over two successive calendar years. Thirty-three unfed colonies served as controls. Supplementary feeding increased fledgling abundance, but had no impact on overwinter survival or population size. We conclude that this depleted suburban sparrow population is not limited by food availability, and conservation efforts based primarily on food provision are unlikely to succeed. We also tested whether cross-colony variation in sparrow abundance was correlated with a set of potential environmental stressors including measures of predator abundance and pollution. Sparrows were more abundant, or showed more positive temporal changes in abundance, at localities containing large areas of seed-rich habitat and low levels of nitrogen dioxide air pollution. Further research is merited into the potential impacts of air pollution on the fitness of urban birds.  相似文献   

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