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1.
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.  相似文献   

2.
The conservation value of urban parks for butterfly communities remains poorly understood, particularly for tropical butterflies in Asia. We conducted point count and route transect butterfly surveys, and used them to sample four habitats located within 13 urban parks across Hong Kong. We found 1054 individuals and 58 species of butterflies recorded in 60 survey hours over 6 months. This represents approximately one quarter of the entire known Hong Kong butterfly species list. Over 30 % of the individuals counted were Catospilia sp. but six of the species identified are classified locally as rare or very rare. Tree-covered habitats and grasslands showed higher butterfly diversity than open areas. The most common butterfly behavior was “directed flight,” which we also found to be habitat-dependent and most common in ponds and open areas. We additionally observed the use of vegetation in urban parks, which included 40 species of nectar plant and four records of butterfly oviposition. The high butterfly diversity, presence of rare species and usage of vegetation (especially as a nectar resource) we documented in this study suggests that urban parks have some conservation value for Hong Kong. However, the use of pesticides and heavy vegetation clearing may limit significant butterfly reproduction and population growth. Altogether these results emphasize the diversity of uses of urban parks for butterflies in Hong Kong while also providing possible directions for improvement in habitat and vegetation management that could increase urban park value for biodiversity.  相似文献   

3.
The paper examines public sector management of urban growth and development in the Riyadh Metropolitan Area, Saudi Arabia. The focus of the paper is on institutional capacity building and development intervention. The paper traces changes in public sector management structures and development activities over the history of the city with the aim of assessing development impact and identifying forces that have shaped the evolving state of urban management. The paper notes that urban management has significantly improved with time but the persistence of urban problems coupled with projections of future growth point to the need for further improvements. The paper, in conclusion, while acknowledging the utility of the metropolitan development strategy (MEDSTAR) being formulated for the city, points to the need for broader administrative reform to improve the ability to cope with long-term challenges of growth in the city. Some issues that reform could address are suggested.  相似文献   

4.
Urban parks constitute critical biodiversity hotspots in crowded, concrete-dominated city environments. Despite the importance, they remain little researched. This paper assesses the biodiversity and distribution of trees in urban parks in the southern Indian city of Bangalore. 127 plots were used to survey tree distribution in parks across the city. The distribution is largely dominated by a few common species. The proportion of exotic species was very high, with 77% of trees belonging to introduced species. Park history had an impact on distribution. Old parks had fewer but larger trees, and greater species diversity compared to recently established parks. Old parks also differed in species composition, having a greater proportion of large canopy trees compared to young parks. Examination of size distributions revealed that large canopied species were gradually being phased out, and replaced by narrow and medium sized tree species which are easier to maintain, but which may not provide the same environmental and ecological benefits. Greater attention requires to be paid to the selection of trees in cities, not just with a view to easy maintenance as is currently the case, but to select an appropriate mix of trees that supports biodiversity and maximizes environmental and ecosystem services.  相似文献   

5.
Increased urbanization typically leads to an increase in abundance of a few species and a reduction in bird species richness. Understanding the structure of biotic communities in urban areas will allow us to propose management techniques and to decrease conflicts between wild species and human beings. The objective of this study was to describe the structure of the bird community in an urban ecosystem. The study was carried out in the city of Taubaté in southeastern Brazil. Point-counts were established in areas with different levels of tree density ranging from urban green spaces to predominantly built-up areas. We looked for a correlation between the richness/abundance of birds and the size of the area surveyed, the number of houses, the number of tree species and the number of individual trees. The results of multiple regression showed that bird richness had a direct relationship with vegetation complexity. The abundance and diversity of tree species were better predictors of bird species than the number of houses and size of the area surveyed. We discuss implications of this study for conservation and management of bird diversity in urban areas, such as the need to increase green areas containing a large diversity of native plant species.  相似文献   

6.
In semi-arid cities, urban trees are often irrigated, but may also utilize natural water sources such as groundwater. Consequently, the sources of water for urban tree transpiration may be uncertain, complicating efforts to efficiently manage water resources. We used a novel approach based on stable isotopes to determine tree water sources in the Los Angeles basin, where we hypothesized that trees would rely on irrigation water in the soil rather than develop deep roots to tap into groundwater. We evaluated the oxygen (δ18O) and hydrogen (δD) isotope ratios of xylem water, irrigation water, soil water, and groundwater in a study of temporal patterns in water sources at two urban sites, and a study of spatial patterns at nine urban sites and one “natural” riparian forest. Contrary to our hypothesis, we found that despite frequent irrigation, some trees tap into groundwater, although in most species this was a small water source. Some trees appeared to be using very shallow soil water at <30 cm depth, suggesting that these mature urban trees were quite shallowly rooted. In the natural site, trees appeared to be using urban runoff in addition to shallow soil water. We were able to identify tree uptake of precipitation at only 3 sites. The results show that some irrigated trees utilize groundwater and do not rely solely on irrigation water, which may make them able to withstand drought and/or water conservation measures. However, some irrigated trees may develop very shallow root systems, which may make them more susceptible.  相似文献   

7.
Occurrences of breeding bird species in 54 urban parks were investigated in the city of Oulu in northern Finland. Park area, human activity, habitat, and landscape structure within a 9-ha square surrounding the study park were related to the bird species richness and occurrence of individual bird species. A total of 22 species was observed. The area of the park explained 39% of the variance of species richness. Seven species (wheatear [Oenanthe oenanthe], common rosefinch [Carpodacus erythrinus], garden warbler [Sylvia borin], lesser whitethroat [Sylvia curruca], linnet [Acanthis cannabina], redpoll [Carduelis flammea], and yellowhammer [Emberiza citrinella]) were not detected in parks of >0.75 ha. Species with lower area demands occurred closer to the town center than species with greater area requirements. Ground-nesting species were poor colonizers of urban parks, whereas high numbers of nest boxes in urban parks attracted many cavity-nesting species. The willow warbler (Phylloscopus trochilus) and the magpie (Pica pica) bred more often in unmanaged than in managed parks, probably because of the greater vegetation cover in unmanaged parks. Park structure variables were entered into models for 7 of the 12 most common bird species, whereas broad scale variables were entered into models for 6 of the 12 species. The number of adjacent buildings had a negative affect on three bird species (the willow warbler, hooded crow [Corvus corone cornix], and spotted flycatcher [Muscicapa striata]). The occurrence of breeding species in urban parks depends on the size of the park, park structure, and landscape structure outside the park.  相似文献   

8.
Research on contemporary union-formation in a Bangkok slum reveals how the meanings of heterosexual matrimony are changing. Dominant popular discourses promote a costly wedding as the socially normative way to marry. This new definition of marriage contrasts with perspectives within the slum, where pre-existing constructs of union-formation take multiple forms. The discursive shift reflects new notions of marriage as a vehicle of upward mobility and modernity. These shifts occur at a time when the Thai state has discursively moralised marriages, facilitating the delegitimisation of cohabitation and other pathways to marriage. The co-existence of ‘traditional’ marriage forms with dominant official ones within the slum highlights the local multiplicity of marital forms. However, as new lifestyle associations between marriage, modernity and civic belonging become increasingly influential, financial constraints and social context mean that these remain hard to access for certain urban migrant sub-populations.  相似文献   

9.
This paper studies the use of ecological research information in urban planning focusing on Finland. Research questions addressed the importance and challenges of incorporating ecological information into the planning process, and ways to promote the use of ecological information. Fifteen key professionals from three representative development approval processes in the Helsinki Metropolitan Area were interviewed. The interviewed planners and ecologists considered ecological information important for identifying and preserving valuable urban nature and biodiversity, diminishing negative environmental impacts of construction and for enabling nature-related experiences and services for urban residents. The identified challenges for the use of the information included insufficiency, fragmented nature and lack of adequacy of information, as well as problems with the interpretation and presentation of information. In order to provide more comprehensive ecological information from urbanizing areas in Finland; there should be more coordinated efforts to produce research information that planners really need, ecologists should be more active in the process in providing ecological insights for plans, a proper and simple biodiversity valuation method should be developed, more research on the function on ecological corridors should be conducted, and biodiversity monitoring of implemented planning projects should be developed.  相似文献   

10.
Grandchildren are sometimes left in the care of their grandparents when parents migrate to find work. Using open-ended interviews with 48 grandparents, this study examines intergenerational relationships in “skipped generation households” in rural Thailand. The qualitative analyses identified several ways in which intergenerational relationships were characterized by solidarity (i.e., emotional closeness, instrumental helping, and financial assistance) as well as conflict (i.e., financial tension, grandchildren’s misbehavior, role confusion). These findings have important implications for practitioners and policymakers that could improve intergenerational relationships in skipped generation households.  相似文献   

11.
刘荣 《城市》2009,(4):69-73
城市交通系统与城市空间发展布局、土地利用之间是一种复杂的互动关系。由1920年~1960年对交通系统与土地利用关系的早期探讨,反映出两派观点:一派的立足点是纽约、费城、芝加哥乃至伦敦、巴黎这些大都市,它们的共同点都是随着铁路通勤方式的发展.城市的形态高度紧凑。并且典型地指向火车站附近的活动中心地:另一派则认为现代城市要面向小汽车为导向的交通系统.进行低密度的“再计划”。  相似文献   

12.
Gray squirrel density,habitat suitability,and behavior in urban parks   总被引:1,自引:1,他引:0  
Increased density, increased intraspecific aggression, and a reduced fear of humans have been suggested as the more observable and frequently described characteristics of wildlife species undergoing synurbization, the process of becoming urbanized. The relationship among these variables and how they may be related to environmental variables that change with urbanization is poorly understood. In this paper we explore the relationship between density, intraspecific aggression, and reduced fear of humans in urban populations of gray squirrel. In the summer and fall of 2003 and 2004, we studied a park with a documented high density of gray squirrels, Lafayette Park, Washington, DC, and six urban parks in Baltimore, MD with unknown squirrel densities. We used linear regression (SAS Institute, SAS/STAT user’s guide. SAS Institute, Cary, NC, 2005) to determine if there was a relationship (P < 0.05) between squirrel density and intraspecific aggression, squirrel density and reduced fear of humans (wariness), and squirrel density and habitat suitability. We found a positive association between density and intraspecific aggression (R 2 = 0.81, P < 0.00). A negative relationship between density and wariness (, P < 0.00). However, no relationship was evident between habitat suitability and squirrel density (, P = 0.437).  相似文献   

13.
Increasing urban development threatens not only breeding habitat for migratory landbirds but also critical stopover habitat. The purpose of this study was to investigate the relationship between landbird community composition and land cover in and surrounding urban park reserves in the Mississippi River Twin Cities Important Bird Area (IBA) in order to evaluate this area’s value during both spring migration and summer breeding seasons. This IBA includes a mosaic of residential, commercial, and park reserve land running along the Mississippi River between Minneapolis and Hastings, Minnesota. Using citizen-science data collected at 8 park reserve sites in the IBA between 2007 and 2010, we calculated species richness, diversity, and evenness for the migrating and breeding landbird community at each site and categorized species into three conservation statuses (species of greatest conservation need, native and exotic) and four migratory behavior classes (permanent residents, short-distance migrants, resident neotropical migrants, and en-route neotropical migrants). We used AIC to rank multiple regression models to evaluate how these groupings vary across sites in comparison to the land cover in and surrounding each site. We found that most measures of both the spring migration and breeding communities were negatively related to increased impervious cover. Exotic species and permanent residents were less affected by surrounding land use, while breeding season resident and transitory neotropical migrants were greatly affected. Patterns of landbird richness and density suggest that removing impervious cover within lower quality sites can improve habitat supporting migrating birds.  相似文献   

14.
Why do racial differences in many indicators of mental and emotional well-being show inconsistent patterns? We propose that mental and emotional well-being are influenced by aspects of the social context, including experiences of unfair treatment and the concentration of households with incomes below the poverty level, and that differential exposure to these factors influences racial differences in mental well-being. We analyze the reporting of psychological distress and life satisfaction in a multistage area probability sample of 1,139 African American and white residents of the Detroit metropolitan area aged 18 and older. Both psychological distress and life satisfaction are significantly associated with exposure to unfair treatment and with the proportion of households in the census block group that were below the poverty level. Racial differences in psychological distress and life satisfaction were eliminated or reversed once differentials in the percent of households living below the poverty line and exposure to unfair treatment were accounted for. These findings contribute to a growing body of evidence that "race" effects operate through multiple pathways that include race-based residential segregation and its attendant economic disinvestment at the community level, and interpersonal experiences of unfair treatment.  相似文献   

15.
Urbanization is rapidly changing the southeastern US landscape, particularly in Georgia within and around the Atlanta metropolitan area, the fastest-growing Southeastern population center. Landscape characteristics related to human disturbance, landscape composition, and landscape configuration vary across the urban-rural gradient and are easily and inexpensively evaluated using geographic information systems (GIS). Previous studies have suggested that avian communities and populations respond in scale-dependent ways to urbanization-related landscape changes through changes in abundance and diversity. We conducted a 2-year study (2007?C2008) of the response of breeding bird population abundance, community abundance, species richness, and relative diversity in young and mature single-family residential areas to 15 landscape characteristics measured at multiple spatial scales across urban-rural development intensity gradients near Athens, Georgia. We grouped birds by species, entire site assemblage, and by functional guild affiliation. Our models suggest strong relationships between the landscape and both community and population abundance of birds, as well as a somewhat weaker relationship with species richness. We detected only a weak relationship between breeding season relative diversity and landscape characteristics; we hypothesize a possible seasonal component to that relationship based on an earlier study. Our results suggest that widely available geospatial metrics of human disturbance and landscape pattern can be used to model breeding bird abundance and diversity across urban-rural gradients. This study sets the framework for a landscape scale understanding of the effects of housing developments and development intensity on breeding birds in northeastern Georgia and such a landscape-based approach to modeling species numbers represents a valuable tool in natural resources management.  相似文献   

16.
Urban Ecosystems - Urbanization causes rapid changes in the landscape and land use, exerting a significant pressure on bird communities. The effect of urbanization on bird diversity has been widely...  相似文献   

17.
A key problem facing slum dwellers is tenure insecurity - as well as the threat of eviction, residents are excluded from many services extended to legal residents, from water connections to public schooling. Thailand’s Baan Mankong slum upgrading program adopts a people-driven approach to resolving problems of insecure housing and poor living conditions, putting slum residents at the core of the process. This paper explores, through interviews, how residents in four Bangkok communities perceive the outcomes of upgrading, particularly their new homes and tenure situation. Participant satisfaction is key to ensuring successful scaling up of Baan Mankong, as this is done through community-driven exchange and learning-by-doing. The results show that while the respondents appreciate their new houses and improved living environment, they are wary of the resulting debt burden. While tenure is regarded as secure in the short term, the long-term situation is not so clear. Homes cannot be sold on outside the community, and therefore Baan Mankong is valued more for improving shelter and strengthening community cohesiveness, rather than as a profit-driven financial investment.  相似文献   

18.
Zhang  Jing  Wang  Xin  Wu  Jiang  Kumari  Deepika 《Urban Ecosystems》2019,22(5):855-863
Urban Ecosystems - Urban parks are an important constituent of cities; they harbour microbial diversity which plays a key role in soil ecosystem functioning. The bacterial diversity of many urban...  相似文献   

19.
Land managers and conservationists face two challenges in protecting land: first balancing human needs against conservation goals, and second demonstrating protected areas are meeting those goals. In this paper, we address the second challenge, using the National Parks of the highly urbanized mid-Atlantic as an example. We detail a comprehensive measure of overall ecosystem integrity, the bird community index, and demonstrate how it relates to the underlying habitat structure. We use community bird data collected from point counts to generate a single, comprehensive metric that we show is significantly correlated to habitat features, making it an effective tool for evaluating ecological integrity. Next, using the metric, we compare bird communities within and outside of protected status, and find that National Parks maintain higher integrity bird communities. This result provides evidence that even smaller parks in highly urbanized areas afford a conservation benefit. More broadly, we find that this rapid and cost effective assessment tool, the bird community index, shows great promise in helping land managers evaluate protected areas.  相似文献   

20.

The Neotropical region has been subjected to massive urbanization, which poses high risks for some global biodiversity hotspots and losses of ecosystem functions and services. In this study, we investigate how distance from large patches of native forests (source areas) and vegetation (green)/and infrastructure (gray) characteristics affect bird species richness and functional diversity in São Paulo megacity, southeastern Brazil. We analyzed the effects of source areas and green/gray characteristics on species richness and functional diversity (richness, evenness, and divergence) indices. We detected 231 bird species, and our data confirmed our predictions: (1) bird species richness in urbanized habitats was found to be (~?50–85%) lower than in source habitats; (2) species richness and trait composition significantly decreased as the distance from the source area increased, while functional richness was not affected by this metric; and (3) shrub and herbaceous covers and maximum height of trees were positively correlated with species richness and unique functional traits regarding habitat, diet, foraging and nesting strata and dispersal ability of birds in the forest-urban matrix. The number of buildings was negatively correlated with bird species richness and functional richness. Maximum height of buildings caused dramatic declines in functional evenness. Functional divergence was notably lower in sites with high shrub cover. Our study stresses the complexity of vegetation embedded in large Neotropical urban settlements and the need to maintain large protected areas surrounding megacities to mitigate the impacts of urbanization on birds.

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