Ant dominance in urban areas

A survey was conducted to determine the distribution of dominant ants and factors that may influence their dominance in New Zealand cities. A new method of active ant trapping combining aspects of pitfall trapping and attraction to food baits was used to capture a sample of all ant species that attended baits. Fifty eight percent of the ant species present in New Zealand were recovered from 2202 traps, with multiple species catches in 245 traps. There was a strong latitudinal relationship in the distribution of ant species, with the proportion of native to introduced species increasing in favour of the native species as latitude increased (south). The presence of Linepithema humile, the Argentine ant, a numerically dominant species was associated with a significant reduction in the number of other ant species captured. With increased urbanisation, providing refugia at times of cool temperatures for warm temperate-sub tropical introduced ant species, their range may extend into the higher latitudes, further displacing native ants from New Zealand cities.     

A conceptual framework for the study of human ecosystems in urban areas

The need for integrated concepts, capable of satisfying natural and social scientists and supporting integrated research, motivates a conceptual framework for understanding the role of humans in ecosystems. The question is how to add humans to the ecological models used to understand urban ecosystems. The ecosystem concept can serve as the basis, but specific social attributes of humans and their institutions must be added. Learning and feedback between the human and natural components of urban ecosystems are key attributes of the integrated model. Parallels with familiar ecological approaches can help in understanding the ecology of urban ecosystems. These include the role of spatial heterogeneity and organizational hierarchies in both the social and natural components of urban ecosystems. Although urban watersheds are commonly highly altered, the watershed approach can serve as a spatial basis for organizing comparative studies of ecosystems exhibiting differing degrees of urbanization. The watershed concept can also spatially organize the hierarchically scaled linkages by which the integrated human ecosystem model can be applied. The study of urban ecosystems is a relatively new field, and the questions suggested by the integrated framework can be used to frame ecosystem research in and associated with urban and metropolitan areas.     

浅析城市居住区道路交通规划

自从有人类活动以来,居住与道路就是相伴发展的。有怎样的居住水平,就需要有怎样的道路与之相适应。人类早期没有固定的住所,因此也没有固定的道路。《尔雅》中说：“道者蹈也,路者露也”,就是说当时的道路是由于人的行走而自然产生的。后来人类逐步形成聚居部落及至出现城市,产生固定的居住区,出现了居住区道路。     

Access to health care in urban areas of developing societies

Emphasis on rural health problems has led to a relative neglect of urban health issues in developing societies. Yet the fact that a large proportion of the limited financial and human resources is allocated to urban health care makes it imperative for researchers and health planners to evaluate the effectiveness of the urban health care system. This paper examines data on health care utilization from a sample survey of 1500 households conducted in three areas of Accra, Ghana in 1982. The factors that influence the use of three types of health care services (clinics, drug vendors, and traditional healers) are examined. Suggestions are made for increasing the effectiveness of the health care system in Accra, with the aim of making medical care more accessible to all families.     

Research on termites in urban areas: approaches and gaps

Urban Ecosystems - Termites comprise a large group of organisms in urban areas, and this leads us to believe that there is a comprehensive literature on the subject, sufficient for conducting a...     

城市居住区的发展模式研究

居住区和城市的发展有着本质的区别,城市的发展与完善是一个长期的过程,而城市居住区的形成时间很短暂,而且一经形成便很难改变.那么,什么样的居住区更符合时代的发展呢?通过分析居住区现有模式以及相关的可变因素,居住区可能会有以下几种发展模式:     

The impact of park trees on microclimate in urban areas

Trees in cities have an important positive effect on people’s lives. One such positive effect is the amelioration of microclimate. The aim of this research is to assess the correlation between parameters that affect the microclimate of parks during the summer. We measured air temperature, relative humidity and solar radiation in the sun and shade of the trees in urban parks in Thessaloniki, Greece. The results indicate that: the air (A) temperature reduction percentage (dTair%), air relative humidity increase (dTRh%), discontent index reduction percentage (DI%) (cooling effect) and solar radiation (L) percentage that passes through the trees’ foliage to their shade creates an exponential function of dA% = a.e-bL. These functions are also applicable to the limiting variation values of the parameters. If we use L = 0 (meaning Lightsh = 0, which is the case for an extremely dense tree), then the values that we expect from this particular parameter are the maximum possible. These maximum values are a characteristic feature of the parameter variation for this particular research area. These maximum values for the trees in the parks of Thessaloniki are: maxdTair% ≈ 24%, maxdRh% ≈ 41% and maxdDI% ≈16%.     

Decay patterns of invasive plants and plastic trash in urban streams

Urban streams are impacted by invasion of exotic riparian plants and the accumulation of plastic trash, which alter in-stream litter subsidies, and cause changes that cascade up the aquatic food web. The impacts of these factors on urban streams is poorly understood. We compared decay rates and invertebrate colonizers of 5 litter pack types in 4 urban streams in Victoria, British Columbia, Canada: Native Red alder (Alnus rubra) and Sitka willow (Salix sitchensis), invasive English ivy (Hedera sp.), Himalayan blackberry (Rubus armeniacus) and plastic trash (i.e. Styrofoam (polystyrene (PS)), plastic bag (high-density polyethylene (HDPE)), and Mylar (polyethylene terephthalate (PET). We tested 4 hypotheses: 1) exotic ivy and blackberry leaves would decay more slowly than native leaves; 2) exotic ivy and blackberry leaves would attract fewer and less diverse stream invertebrates than native leaves; 3) plastic trash would decay more slowly than leaves; and, 4) plastic trash would attract fewer and less diverse stream invertebrates than leaves. We found no difference between the leaf litter decay rates, however plastic trash decayed more slowly than leaves. Trash decay rates were faster than reported in marine environments, suggesting that plastic trash removal should be a management priority. Stream invertebrates colonized all pack types equally. We observed significant differences in litter decay rates and invertebrate assemblage alpha and Shannon–Wiener diversities across the 4 streams - likely related to differences in stream-specific environmental attributes including flashiness, stream discharge, and biological decay. We conclude that site-specific decay forces supersede litter quality in Pacific Coast urban streams.     

Poverty and poverty alleviation programmes in the urban areas of Mozambique

The first part of this paper provides an analysis of poverty and destitution in the cities of Mozambique. The second part summarises the existing programmes for poverty alleviation and the social safety net. The last part describes in some detail the only organisation and programme which has had significant impact in terms of alleviating poverty and destitution: the Gabinete de Apoio a População Vulnerável (GAPVU) Cash Transfer Scheme.A poverty profile of Mozambique's urban centres shows that over half of all households are living in poverty. It distinguishes between absolutely poor and destitute households. The latter have expenditures less than two thirds of the poverty line, are at risk of malnutrition, high child mortality and low life expectancy and comprise nearly a third of the population. A distinction is made between structural and conjunctural causes of poverty and used as a basis for classifying households in different situations, in order to identify appropriate types of intervention. Existing policies and programmes to reduce poverty and alleviate destitution are reviewed and their strengths and weaknesses identified. The cash transfer scheme designed and operated by the GAPVU is described in more detail, and its effectiveness in reaching destitute households assessed. Finally, its administrative efficiency and financial and institutional sustainability are evaluated. It is shown to be a well designed programme which succeeds in reaching increasing numbers of vulnerable households because of its use of decentralised health and community administrative structures, and strong political and institutional backing.     

Urban Morphology types and open space distribution in urban core areas

Urban cores are primarily associated with economic activity: they are places where people live, work and engage in a range of leisure activities. Natural elements within the environment are recognised as having an important role in promoting quality of life. An investigation into the urban character of Manchester City Centre (UK) combining an analysis of the surface cover with the mapping of urban morphology types (UMTs) shows the extent to which green space permeates the built matrix. Around 20% of the urban core was covered by evapotranspiring surfaces. UMTs were differentiated along axes which were characterised by the intensity of grassland management and the density of building. The results presented here contribute to the on going debate around the development of cities and the relationship between the natural and built environments and provide guidance for those challenged with designing these environments.     

Super-diversity and the art of living in ethnically concentrated urban areas

This article discusses how local diversity is being experienced by Somali immigrants who have previously lived in the Netherlands and are now residing in London. It explores the various challenges and potential advantages of living in homogenous urban areas within a super-diverse city and focuses on three situations: (1) when homogeneity is functional and leads to living in parallel worlds; (2) when homogeneity creates social reproduction, even when located in a super-diverse city; and (3) when people manage to oscillate between both worlds – i.e. between homogenous urban areas and the potential offered by a super-diverse city. The article argues that migrants trace different pathways in the context of super-diversity. They have the ability to operate at different scales – the locale and the cosmopolitan super-diverse metropolis. However, the most vulnerable people have more difficulty in accessing and benefiting directly from the potential offered by super-diversity.     

对天津市区自行车交通的思考和建议

自行车交通体现了绿色交通的理念,它的存在对城市交通可持续发展具有重要的意义。本文对自行车交通的现状与问题、发展前景、改善天津市自行车交通的建议等做了论述。一、现状与问题目前天津市区自行车实际使用总量约280～300万辆,户均2辆,人均0.76辆,基本上达到适龄骑车人人均1辆的水平。自行车仍是天津城市居民主要的交通出行工具。2000年城市居民出行结构中,自行车交通处在首位,占出行结构总量的51%(步行占34.6%,公交车出行占6.4%),但与1993年比较,自行车出行比例下降9.48%(步行增加6.64%,公交车出行增加2.34%)。如果再把自行车交通与公…     

Exotic monk parakeets (Myiopsitta monachus) in New Jersey: nest site selection, rebuilding following removal, and their urban wildlife appeal

Understanding how birds exist in highly urban cities is important to maintaining biodiversity within these environments, and exotic species pose a unique opportunity to examine adaptation. The non-native monk parakeet (Myiopsitta monachus) nests mainly in cities in the United States, and in some places, is considered a nuisance by utility companies. Monk parakeets nest communally (many nests in one nest structure) and colonially (many nest structures in one area). We studied monk parakeets in urban New Jersey to determine where they nested, if nest sites were similar among parakeets nesting in trees and utility poles, and if they rebuilt following removal. Of the 51 nest structures we studied, 37% were on utility poles, 8% were on a man-made gazebo, and the rest were in trees. Nest structures located on poles were located closer to the ground, had fewer nest holes, and the distance to nearest tree was greater than for tree nest structures. The pole nest structures were closer to the top of the “canopy” or structure, and were always located on or around the pole rather than out on one of the cross beams. The nest structures were similar in size and shape whether they were located on poles, other man-made objects, or in trees. Thus monk parakeets built similar nest structures, and located them about the same distance from the ground and from houses whether they were in utility poles or in trees, leading to the conclusion that poles provide suitable sites for them. The parakeets persisted in nesting on the utility poles and another man-made gazebo despite being removed over several years, and despite the presence of other nearby unused trees. After parakeet nest structures were removed from poles by the utility company, most birds began rebuilding within the day. The persistence, despite persecution, of the monk parakeet on poles, and the fact that poles provide attractive and secure support for nest structures, suggest that they will continue to do so. Managers must either learn to live with the parakeets, redesign the utility pole structure to be less appealing to the birds, provide them with alternative nest sites on the utility poles or nearby, or continue to forcibly remove them. Local support for the parakeets, and their potential to serve as urban icons, have resulted in New Jersey’s utility company working with local enthusiasts and scientists to ensure the birds are not harmed during nest removal.     

The genesis,classification, and mapping of soils in urban areas

This paper discusses the concept of soil in both urban and rural environments, and along the urban-rural land use gradient, to illustrate the obvious need to increase our understanding of urban soils. Spatial variability of the urban landscape is illustrated with "Soil series - Urban land complexes" from Baltimore County, Maryland. The World Reference Base for Soil Resources (ISSS-ISRIC-FAO, 1994) proposed Anthrosol and Regosol major soil groups are discussed to show modern approaches to soil classification and to illustrate how the classification of urban soils is essentially undeveloped. Models of soil genesis help identify the processes and functions of the soil system. A conceptual model using Jenny's (1941) state factor approach for human impact on soil formation details the "anthroposequence." The benchmark anthroposequence model may be applied to studying soil systems along urban-rural land use gradients. The process of "anthropedogenesis" is supported to quantify the role of human activity in changing the "natural" direction of soil formation. Future directions of soil research in the urban landscape should involve large scale soil mapping (e.g. 1:6000), benchmark anthroposequences, improved soil classification, and refined characterization of the role of human activities in soil formation.     

Colonization and habitat selection of a declining farmland species in urban areas

Despite the accelerating global urbanization and its associated implications for wildlife and humans, we know little about the biology of urban ecosystems. Here, we investigated colonization and habitat selection of the European hare (Lepus europaeus), a declining farmland species, in urban areas in Denmark, using a combination of citizen science data and transect counts. Further, we estimated the population density of urban hares in Aarhus, Denmark’s second largest city. Our results provide the first evidence that hares have established populations in urban areas, potentially in response to decreasing habitat quality in rural areas due to agricultural intensification. The hare density in Aarhus was ca. 8 hares per km², which is comparable to or slightly higher than hare abundance estimates from various pastural areas in Europe, suggesting that urban areas provide suitable habitat for hares. Hare habitat selection was generally associated with areas consisting of large lawns, such as high buildings and parks, which potentially provide high-quality forage throughout the year. Considering the increasing expansion of urban areas and deteriorating habitat quality of agricultural areas, urban planning that incorporates habitat requirements for wildlife could help to support urban animal populations, especially for species of conservation concern.

     

Social-ecological research in urban natural areas: an emergent process for integration

Urban Ecosystems - Understanding the structure and function of urban landscapes requires integrating social and ecological research. Here, we integrate parallel social and ecological assessments of...     

Small mammal assemblages in fragmented shrublands of urban areas of Central Chile

Mediterranean-type ecosystems are one of the most affected environments by habitat loss and fragmentation due to urban development, however only few studies have evaluated the effects of urbanization on the biodiversity of remnant fragments in these ecosystems. This study aims to evaluate the effects of urban development over small mammal assemblages inhabiting isolated forest fragments of an urban area of Chilean Mediterranean zone. We compared abundance and richness of small mammal assemblages of six remnant fragments within an urban matrix, and six fragments similar in area and habitat characteristics with those of urban area, but surrounded by a rural matrix. We found that small mammal assemblages differ considerably among fragments types (urban vs rural), with lack of endemic species from urban fragments and with high proportion of introduced rodents in urban fragments. Furthermore abundance of small mammals was higher in rural than in urban fragments. In urban areas small mammal abundance and richness were not correlated with any of the explanatory variables assessed (woody cover, flora heterogeneity, fragment area, perimeter/area ratio). However in rural fragments small mammal richness was negatively correlated with flora heterogeneity and the abundance of small mammals was positively correlated with perimeter/area ratio. These results reveal important differences within the effects of fragmentation over small mammal assemblages among the two types of fragments assessed. Our findings suggest that in forest fragments isolated by urbanization, larger areas with good quality habitats are not sufficient to maintain native small mammal population.