Urbanization does not affect green space bird species richness in a mid-sized city

Urban Ecosystems - Urbanization is one of the most intensive forms of landscape and habitat transformation, resulting in species loss, and taxonomic and functional homogenization of different...     

Urbanization affects the trophic structure of arboreal arthropod communities

Urbanization is one of the most significant causes of habitat fragmentation on the planet, resulting in substantial losses of biodiversity and disruptions to ecological processes. We examined the effects of urbanization on the diversity and abundance of arboreal invertebrates in a dominant tree species (Angophora costata) in a highly urbanized landscape in Sydney, Australia, identifying the potential ecological consequences of shifts in diversity. We hypothesized that trophic structure would be influenced by landscape context with a greater richness and abundance of invertebrates in small remnants and edges. Canopy arthropods were sampled via beating from trees in 15 sites in three landscape contexts; five large patches of continuous vegetation, five edges of large patches and five small urban remnants. Trees in large patches supported fewer individuals compared to trees in small urban remnants and edge sites. The composition of assemblages and overall trophic structure also differed between edges and large patches, with a greater abundance of grazing insects in edges. No differences were detected between small urban remnants and edges, suggesting that observed differences might be attributed to an edge effect as opposed to an area effect per se. These changes in trophic structure, revealing a greater abundance of grazing herbivores and a reduced abundance of predators and parasitoids in edge sites, are consistent with work describing elevated levels of herbivory in edges of remnant vegetation. Future management of remnant urban vegetation and associated biodiversity requires not only an understanding of how trophic status influences the extent of responses by arboreal invertebrate communities, but also how these will affect ecosystem functioning.     

The effects of trampling on assemblages of ground beetles (Coleoptera,Carabidae) in urban forests in Helsinki,Finland

The occurrence of carabid beetles in relation to trampling was examined in urban forest sites located in the city of Helsinki, southern Finland. The degree of wear of the forest floor was assessed and used as a measure of trampling intensity. In particular, we examined the following predictions: (1) carabid diversity should decrease with increasing trampling intensity, (2) mean body size of the dominating carabid species should decrease with increasing trampling intensity, and (3) opportunistic species should gain dominance in severely trampled sites. In total, 1,326 beetles representing 27 species were captured. The first prediction was not supported, as there was no correlation between species richness or Hill's N2 diversity index and trampling intensity. However, there was a positive correlation between number of carabids captured and trampling intensity of the site. The second hypothesis gained some support, as there was a marginally significant negative correlation between body size and trampling intensity. The hypothesis that opportunistic species should gain dominance in severely trampled sites was supported as one species was very dominant (Pterostichus melanarius, 60.0%) in the heavily trampled sites, while there were two equally and less dominant species in the less trampled sites. Individual species did show different responses to the effects of trampling, and the most sensitive forest species may not survive in the heavily trampled sites. We conclude that at the community level (e.g., species richness, diversity), the effects of trampling on carabids in urban forests are subtle, but impacts are pronounced for some sensitive species.     

Local and landscape drivers of arthropod abundance,richness, and trophic composition in urban habitats

Urban green spaces, such as forest fragments, vacant lots, and community gardens, are increasingly highlighted as biodiversity refuges and are of growing interest to conservation. At the same time, the burgeoning urban garden movement partially seeks to ameliorate problems of food security. Arthropods link these two issues (conservation and food security) given their abundance, diversity, and role as providers of ecosystem services like pollination and pest control. Many previous studies of urban arthropods focused on a single taxon (e.g. order or family), and examined either local habitat drivers or effects of landscape characteristics. In contrast, we examined both local and landscape drivers of community patterns, and examined differences in abundance, richness, and trophic structure of arthropod communities in urban forest fragments, vacant lots, and community gardens. We sampled ground-foraging arthropods, collected data on 24 local habitat features (e.g., vegetation, ground cover, concrete), and examined land-cover types within 2 km of 12 study sites in Toledo, Ohio. We found that abundance and richness of urban arthropods differed by habitat type and that richness of ants and spiders, in particular, varied among lots, gardens, and forests. Several local and landscape factors correlated with changes in abundance, richness, and trophic composition of arthropods, and different factors were important for specific arthropod groups. Overwhelmingly, local factors were the predominant (80 % of interactions) driver of arthropods in this urban environment. These results indicate that park managers and gardeners alike may be able to manage forests and gardens to promote biodiversity of desired organisms and potentially improve ecosystem services within the urban landscape.     

Ergonomic work analysis of urban bus drivers in Rio de Janeiro city

This article is the result of a case study on ergonomic work analysis carried out in an urban bus company located in Ilha do Governador, Rio de Janeiro. The methodology used in this work follows the French-tradition Ergonomic Analysis of the Work (EWA) combined with the best tradition from anglo-saxon ergonomic work analysis. The situated diagnosis was performed to provide relevant information about the work conditions of a bus driver.     

Attitudinal and structural drivers of preferred versus actual residential landscapes in a desert city

Urban Ecosystems - Residential landscaping decisions can have important implications for water use and conservation in urban areas. Yard preferences are generally closely related to actual yard...     

Urbanization impacts the taxonomic and functional structure of aquatic macroinvertebrate communities in a small Neotropical city

Due to habitat fragmentation, resource disruption and pollution, urbanization is one of the most destructive forms of anthropization affecting ecosystems worldwide. Generally, human-mediated perturbations dramatically alter species diversity in urban sites compared to the surroundings, thus influencing the functioning of the entire ecosystem. We investigated the taxonomic and functional diversity patterns of the aquatic macroinvertebrate communities in tank bromeliads by comparing those found in a small Neotropical city with those from an adjacent rural site. Changes in the quality of detrital inputs in relation to lower tree diversity and the presence of synanthropic species are likely important driving forces behind the observed structural changes in the urban site. Leaf-litter processors (i.e., shredders, scrapers) were positively affected in the urban site, while filter-feeders that process smaller particles produced by the activity of the shredders were negatively affected. Because we cannot ascertain whether the decline in filter-feeders is related to food web-mediated effects or to competitive exclusion (Aedes aegypti mosquitoes were present in urban bromeliads only), further studies are necessary to account for the effects of intra-guild competition or inter-guild facilitation.     

The role of woodpeckers (family: Picidae) as ecosystem engineers in urban parks: a case study in the city of Madrid (Spain)

Urban Ecosystems - Many species of the family Picidae, such as the woodpeckers, excavate the tree-cavities where they nest. Frequently the cavities are used during a single breeding season and...     

Political Participation of Local Publics in the Unemployment Field: A Comparison of Lyon and Turin

This article focuses on political participation of local publics in the unemployment field, examining networks of collective actors in Lyon and Turin. Our main question is: Is the participation of local publics fostered under conditions of more developed governance that increases bottom-up access (formal or informal) to elites and institutions in the policy domain? Drawing upon the most recent developments in literatures on social movement theory, governance and network analysis, this article discusses the main variations in terms of political participation of local publics in Lyon and Turin. It then enquires into the main explanatory factors accounting for these variations, thus showing that the openness of governance does influence the level of political participation of local publics. The main argument is that in an open context participation is low, while in a closed (or underdeveloped) context local publics participate more, with differential access to decision-making according to their resources.     

Genets in the city: community observations and perceptions of large-spotted genets (Genetta tigrina) in an urban environment

Urban Ecosystems - The global increase in urbanization has resulted in exclusion of many carnivore species from human-altered landscapes due to a variety of anthropogenic impacts. However, despite...     

Development of the Geographical Proportional-to-size Street-Intercept Sampling (GPSIS) method for recruiting urban nightlife-goers in an entire city

Abstract

We developed the Geographical Proportional-to-size Street-Intercept Sampling (GPSIS) method in order to obtain a sample of nightlife-goers which accounted for the diversity of spaces, patrons and locations within two Swiss cities. Popular nightlife zones were identified and quantified using social media data and local experts’ knowledge. Young people were recruited in the streets on Friday and Saturday nights on three consecutive weekends using the ‘fixed-line method, pro-rated for the zone’s estimated popularity. Of the 3092 young adults approached, 896 agreed to pre-register. The importance of recruitment in multiple zones and over multiple weekend-days was evidenced by significant variations in participant demographics and registration rates between recruitment zones, times and weather conditions. To conclude, by combining a geographical approach with in situ recruitment, GPSIS has considerable potential as a tool for recruiting samples that represent the diversity of the nightlife population and spaces.     

Public space,collective memory and intercultural dialogue in a (UK) city of culture

Using the case study of Derry~Londonderry and its designation as ‘UK City of Culture 2013’, the primary objective of this research paper is to critically analyse the challenges associated with the production of a year-long cultural programme in a culturally and politically divided place. Given that Northern Ireland’s second largest city has been understood in terms of a conflict between ‘two traditions’, Irish/Catholic and British/Protestant, we critically assess the dialogue and policy negotiations with reference to public places as well as representations of collective memory and traditional music during the year. Fieldwork over two years has enabled us to investigate how culture and identity politics are played out in the context of a city undergoing a process of reconciliation. Placing our case study in a strongly comparative context, we argue that cultural concerns are pivotal points of (re-)negotiation in any society transitioning from conflict to ‘peace’ and that this issue, therefore, is of vital concern to academics and policymakers alike internationally.     

Urbanization and warming of Phoenix (Arizona,USA): Impacts,feedbacks and mitigation

This paper examines the impacts, feedbacks, and mitigation of the urban heat island in Phoenix, Arizona (USA). At Sky Harbor Airport, urbanization has increased the nighttime minimum temperature by 5°C and the average daily temperatures by 3.1°C. Urban warming has increased the number of misery hours per day for humans, which may have important social consequences. Other impacts include (1) increased energy consumption for heating and cooling of buildings, (2) increased heat stress (but decreased cold stress) for plants, (3) reduced quality of cotton fiber and reduced dairy production on the urban fringe, and (4) a broadening of the seasonal thermal window for arthropods. Climate feedback loops associated with evapotranspiration, energy production and consumption associated with increased air conditioning demand, and land conversion are discussed. Urban planning and design policy could be redesigned to mitigate urban warming, and several cities in the region are incorporating concerns regarding urban warming into planning codes and practices. The issue is timely and important, because most of the world's human population growth over the next 30 years will occur in cities in warm climates.     

Sniffing the city: issues of sousveillance in inner city London

This article reflects on a series of workshops run by the art/media/hacktivist collective Deptford.TV in collaboration with the Centre for Urban and Community Research (CUCR), Goldsmiths, University of London in 2009–2010 and in 2012. The aim of the workshops was to create short films using hacked CCTV material. Participants, equipped with digital video signal receivers, were led through the city by incoming surveillance camera signals. Receivers cached surveillance camera signals making a range of city spaces visible. The material was then stored on a shared video platform and reshuffled in personal narratives and montages of the city. Hackers and media artists call it ‘sousveillance’ and frame it as a critique of the ‘panopticon society’. I argue that this practice reveals an unusually realistic portrait of inner city London and its working-class population at their everyday work. My contention is that the absence of such activities in narratives of gentrification and the presumed end of manual work make this portrait particularly valuable. The article evaluates this emerging and ethically controversial practice of video recording, asking to what extent it can become a useful tool for urban scholars, visual sociologists and media artists. In conclusion, I argue that the exercise provides moments of self-discovery for the urban stroller, who – while practicing a sort of heroic immersion in inner city London – paradoxically becomes a watcher of scenes from life fabricated at a ‘safe’ distance; a middle way between urban ethnographer and flâneur.     

Instrumentality and Community in the Process of Urbanization

Comparative empirical evidence is presented to show the basic instrumentality of low-income urban dwellers to the existential circumstances they face. In Latin America, urban dwellers have seemingly internalised the urban/industrial values of capitalist society and, depending on the availability of jobs and other urban resources and facilities, choose the most rewarding strategy for obtaining benefits. Given the general lack of a well-established structure of secondary industry and the particularistic procedures presently most appropriate for getting jobs and other resources, the motives and basis for communal and collective action are lacking. This is seen most clearly in the example of squatting, where short-term collective action does not develop further, once the objectives of the squatters are achieved. Various forms of instrumental action are expressed in a typology based on subjective orientations and objective opportunities. In the light of the evidence cited, discussions of "marginality,""urban social movements" and "restructuring of community" are misplaced.     

Seasonal dynamics of bird communities in urban forests of a Mediterranean city (Montpellier,Southern France)

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.     

Influence of urban landscape structure on bird fauna: a case study across seasons in the city of Valencia (Spain)

Studies on bird fauna of urban environments have had a long history, but the potential of studies mapping the distribution of birds in cities probably has not fully developed. The bird fauna of the municipality of Valencia (Spain) was studied to determine the influence of urbanization on bird species richness and abundance. Birds were censused during winter and the breeding season of years 1997–1998 in 197 squares measuring 49 ha each from a rural and an urbanized area. Across seasons the number of species decreased around 40% in the city compared with the rural landscape surrounding it. Such pattern could be attributed to the low number of farmland species capable to use the habitats inside the city, and the limited ability of urban parks in attracting woodland species. In the urban landscape, the influence of the dimensions and spatial arrangement of habitat patches was outweighed by the amount of each habitat per square. Bird richness and the abundance of most species were negatively related with the amount of built-up habitat per square and positively with the amount of urban parks, and of habitat diversity. Conversely, bird fauna was largely independent of mean park size per square especially during winter, indicating that at the landscape scale even small patches of habitat could play an ecological role. Conservation of urban bird diversity could benefit of two complementary strategies: (i) the protection of the surrounding rural landscape from urban development; (ii) habitat enhancement within the city. Particularly, a proper design and habitat management of urban parks could improve their suitability for urban bird fauna.     

珠三角地区城镇化质量评价

在借鉴已有城镇化质量指标体系优点的基础上,结合新型城镇化要求,从城市发展质量、城镇化效率和城乡协调发展三方面构建了由33个指标构成的综合评价体系,并采用2014年珠三角地区的相关数据,综合运用主客观赋权法对珠三角9市的城镇化质量进行了评价。