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.     

Modeling urban landscape dynamics: A case study in Phoenix,USA

Urbanization has profoundly transformed many landscapes throughout the world, and the ecological consequences of this transformation are yet to be fully understood. To understand the ecology of urban systems, it is necessary to quantify the spatial and temporal patterns of urbanization, which often requires dynamic modeling and spatial analysis. In this paper, we describe an urban growth model, the Phoenix Urban Growth Model (PHX-UGM), illustrate a series of model calibration and evaluation methods, and present scenario-based simulation analyses of the future development patterns of the Phoenix metropolitan region. PHX-UGM is a spatially explicit urban landscape model and is a modified version of the Human-Induced Land Transformations (HILT) model originally developed for the San Francisco Bay Area. Using land use and other data collected for the Phoenix area, existing growth rules were selectively modified and new rules were added to help examine key ecological and social factors. We used multiple methods and a multi-scale approach for model calibration and evaluation. The results of the different evaluation methods showed that the model performed reasonably well at a certain range of spatial resolutions (120–480 m). When fine-scale data are available and when landscape structural details are desirable, the 120-m grain size should be used. However, at finer levels the noise and uncertainty in input data and the exponentially increased computational requirements would considerably reduce the usefulness and accuracy of the model. At the other extreme, model projections with too coarse a spatial resolution would be of little use at the local and regional scales. A series of scenario analyses suggest that the Metropolitan Phoenix area will soon be densely populated demographically and highly fragmented ecologically unless dramatic actions are to be taken soon to significantly slow down the population growth. Also, there will be an urban morphological threshold over which drastic changes in certain aspects of landscape pattern occur. Specifically, the scenarios indicate that, as large patches of open lands (including protected lands, parks and available desert lands) begin to break up, patch diversity declines due partly to the loss of agricultural lands, and the overall landscape shape complexity also decreases because of the predominance of urban lands. It seems that reaching such a threshold can be delayed, but not avoided, if the population in the Phoenix metropolitan region continues to grow. PHX-UGM can be used as a tool for exploring the outcome of different urban planning strategies, and the methods illustrated in this paper can be used for evaluating other urban models.     

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.     

Norms,status and the dynamics of advice networks: A case study

The issue of the influence of norms on behavior is as old as sociology itself. This paper explores the effect of normative homophily (i.e. “sharing the same normative choices”) on the evolution of the advice network among lay judges in a courthouse. 0020 and 0025 social exchange theory suggests that members select advisors based on the status of the advisor. Additional research shows that members of an organization use similarities with others in ascribed, achieved or inherited characteristics, as well as other kinds of ties, to mitigate the potentially negative effects of this strong status rule. We elaborate and test these theories using data on advisor choice in the Commercial Court of Paris. We use a jurisprudential case about unfair competition (material and “moral” damages), a case that we submitted to all the judges of this court, to test the effect of normative homophily on the selection of advisors, controlling for status effects. Normative homophily is measured by the extent to which two judges are equally “punitive” in awarding damages to plaintiffs. Statistical analyses combine longitudinal advice network data collected among the judges with their normative dispositions. Contrary to what could be expected from conventional sociological theories, we find no pure effect of normative homophily on the choice of advisors. In this case, therefore, sharing the same norms and values does not have, by itself, a mitigating effect and does not contribute to the evolution of the network. We argue that status effects, conformity and alignments on positions of opinion leaders in controversies still provide the best insights into the relationship between norms, structure and behavior.     

Conceptualising the vertical landscape: The case of the International Finance Centre in the world's most vertical city

This article introduces the crucial yet much overlooked dimension of verticality to landscape‐related research through a case study of one of the most iconic skyscrapers in Hong Kong, the world's most vertical city. A tripartite analytic model is proposed to examine the dialogical interaction between the discursive and material landscapes in a vertical layout, while at the same time to explore the intricate interrelations among social actors, practices, functions of space, levels of access and forms and functions of semiotic resources, all within one single site of varying levels of verticality. In the process, the study reveals the vertical space as a highly stratified and hierarchical system, and underlines the value of taking a functional approach to verticality in order to deepen our understanding of its indexical social meaning and its role as an active agent both in reflecting and shaping social stratification in today's globalised and consumerist world.     

Work,family and public policy dynamics in France

To understand the relationships between changes to the family and changes to the sphere of work and employment, and how they have developed over time, requires considering a third factor, i.e. public policies, and in particular family policies. In this article, we attempt to clarify theoretically these interactions by taking into account the changes that have taken place in France since World War II. To appraise the French configuration in a special issue on Southern Europe, we begin by explaining why we consider France is following a ‘Southern path’. In a second section, we argue that family transformations are mainly the result of changes that affect work and employment. A similar process combining individualisation, flexibility and precariousness is affecting both spheres of existence. In a last section, we prose a matrix of ideas, ideologies and outcomes to understand the main family policy reforms since World War II.     

城市、建筑、园林三位一体的建筑科学

城市、建筑、园林三者密不可分,三位一体.只有认识到这一点才能继承和发展具有中国特色的建筑科学.现代城市是一个开放复杂的巨系统,建筑科学大部门也是开放复杂的巨系统.在具体研究建筑科学时,必须注意定性与定量相结合,正确处理开放复杂的巨系统与其众多子系统的关系.     

Flood-resilient urban design based on the indigenous landscape in the city of Can Tho,Vietnam

Urban Ecosystems - Natural conditions and indigenous culture are fundamental factors creating the hydrological landscape system of the Vietnamese Mekong Delta. A study of the indigenous landscape...     

Ecological consequences of fragmentation and deforestation in an urban landscape: a case study

Landscape change is an ongoing process even within established urban landscapes. Yet, analyses of fragmentation and deforestation have focused primarily on the conversion of non-urban to urban landscapes in rural landscapes and ignored urban landscapes. To determine the ecological effects of continued urbanization in urban landscapes, tree-covered patches were mapped in the Gwynns Falls watershed (17158.6?ha) in Maryland for 1994 and 1999 to document fragmentation, deforestation, and reforestation. The watershed was divided into lower (urban core), middle (older suburbs), and upper (recent suburbs) subsections. Over the entire watershed a net of 264.5 of 4855.5?ha of tree-covered patches were converted to urban land use??125 new tree-covered patches were added through fragmentation, 4 were added through reforestation, 43 were lost through deforestation, and 7 were combined with an adjacent patch. In addition, 180 patches were reduced in size. In the urban core, deforestation continued with conversion to commercial land use. Because of the lack of vegetation, commercial land uses are problematic for both species conservation and derived ecosystem benefits. In the lower subsection, shape complexity increased for tree-covered patches less than 10?ha. Changes in shape resulted from canopy expansion, planted materials, and reforestation of vacant sites. In the middle and upper subsections, the shape index value for tree-covered patches decreased, indicating simplification. Density analyses of the subsections showed no change with respect to patch densities but pointed out the importance of small patches (??5?ha) as ??stepping stone?? to link large patches (e.g., >100?ha). Using an urban forest effect model, we estimated, for the entire watershed, total carbon loss and pollution removal, from 1994 to 1999, to be 14,235,889.2?kg and 13,011.4?kg, respectively due to urban land-use conversions.     

Novel woodland patches in a small historical Mediterranean city: Padova,Northern Italy

Urban Ecosystems - Woodland fragments, in small historical cities, are commonly regarded as temporary voids in an urban matrix, yet to be allocated a land-use, under city planning regulations....     

Birds biodiversity in urban and periurban forests: environmental determinants at local and landscape scales

A significant decline in biodiversity is associated with the current and upcoming degree of urbanization. A challenging strategy to address this conflict is to make urban growth compatible with biodiversity protection and in this context urban parks can play a crucial role. Urban systems are highly dynamic and complex human-shaped ecosystems, where the relationship between species and environment may be altered and make the preservation of biodiversity within them a challenging goal. In this study, we analysed how different environmental features affect bird biodiversity in one of the most urbanized areas of Italy (the metropolitan area of Milan) at different spatial scales. Bird surveys were conducted in fifteen urban and peri-urban parks and environmental variables at landscape and local scale recorded. Results showed that a mixture of land covers and the presence of water bodies inside urban parks favoured species occurrence and abundance at landscape scale, but a surrounding dense urban matrix deflated biodiversity. At local scale, woodland cover and presence of water bodies were key determinants in ensuring overall high biodiversity but local-specific vegetation management produced an unusual pattern for forests species. In particular, the maintenance of large trees may not result in biodiversity support for forest bird species if large trees are not located in woodland areas with a significant tree density. To understand biodiversity patterns and provide useful information for urban planning and design, we need to provide insights into species/environment relationships at multiple scales in the urban environment.     

Alerts and catastrophes: The case of the 1999 storm in France,a treacherous risk

How is it that catastrophes always seem predictable ex post but never ex ante? The paradox is recurrent. Our study of the warnings issued prior to one of the last major natural disasters in France – the tempest of December 27, 1999 – focuses on the organizational factors accounting for the surprise effect of the catastrophe, to try and understand why, though the phenomenon had been predicted and announced by the French weather bureau, the protagonists of Civil Defense said the magnitude of the event took them by surprise. A multi-level, qualitative analysis of the inter-organizational meteorological alert system shows that a combination of factors pertaining to structure, context and individuals transformed the warnings into routine messages. The case of the 1999 storm allows us to introduce a particular, ideal-type of risk, the treacherous risk, which, though clearly announced, was disregarded because seemingly so familiar.     

Native and exotic species in the urban landscape of the city of Rio de Janeiro,Brazil: density,richness, and arboreal deficit

Shaped by European influences, the Brazilian urban landscape was marked by the predominant use of exotic species in planted areas. In the 19th century along the city streets of Rio de Janeiro, trees were planted at a standard distance from each other. With time, native species began to be used in the urban landscape. Our purpose was to evaluate the utilization of exotic plant species in the urban landscape of Rio de Janeiro, evaluate the city’s arboreal deficit, and relate its neighborhood arboreal density to its economic index. Arboreal deficit represents the negative difference between the total number of expected trees and the observed number in the streets based in the standard distance used in the past. Twenty native and 40 exotic species were found in the 1701 streets sampled. A high percent of streets did not have any planted trees and the number of trees was greater in wealthier neighborhoods. The strong prevalence of exotic species is indicative of the negative impact of human activity on the biota. Since the municipality of Rio de Janeiro harbors forested areas, the risk for dissemination of exotic species is high.     

Population aging and long-term care policies in the Gulf region: a case study of Oman

Population aging is a phenomenon occurring across the globe including in countries traditionally exhibiting population dividends and “youth bulges.” The Gulf Corporation Council countries are no exception as they currently experience a process of population aging, albeit at a different stage from many developed countries. However, due to historically high fertility rates and fast-paced epidemiological transition, some of these countries will experience population aging at a higher pace than what has been observed in Europe and the United States. This article reviews recent developments in long-term care policies in the Gulf region with a focus on Oman as an example of a high-income Arab country that is experiencing population aging while still being governed by traditional family aged-care norms. Utilizing existing data and published research complemented by policy analysis and field visits, we analyze the process of population aging in Oman and neighboring countries and its policy implications.     

Specific niche requirements drive long-term survival and growth of translocated epiphytic orchids in an urbanised tropical landscape

Urbanisation is expanding at an unprecedented rate, affecting multiple taxa the world over. Ex situ conservation practices in urban areas (e.g. managed relocation) can help mitigate species extinction. However, systematic evaluations of ex situ practices and quantification of niche spaces, especially in urban areas, are largely lacking. Using epiphytic orchids as a study system, we translocated 13 propagated native species (2251 individuals) on 99 host trees across six urban sites. After 5 years, 12 of 13 species showed survival rates above 50% and 9 of 11 species exhibited positive growth. Generalised linear mixed models revealed that species and presence of humus corresponded to orchid survival, whereas the fork microsite and height from ground corresponded to orchid growth. Species-wise, the biophysical factors that were associated with survival and growth varied widely, with 7 of 11 species showing distinct interactions with more than one factor. Notably, the presence of humus and relative humidity influenced the survival of 4 of 11 species. This study suggests that managed relocation can serve as a viable conservation strategy for native orchids and possibly other epiphytes as well. We propose that species-specific niche requirements are identified and integrated into intervention actions.     

A social ecology approach and applications of urban ecosystem and landscape analyses: a case study of Baltimore,Maryland

The early interactions between plant, animal, and human ecology in the 1920s in the United States provide an initial basis for understanding and directing an integrated ecosystem approach to the study of sociocultural and biophysical patterns and processes of present day cities. However, whereas the human ecology approach of the 1920s and 30s was interested in metaphorical similarities with plant and animal ecologists, we propose a more integrated approach to human ecosystem observation and analysis. A critical feature to an integrated, urban ecosystem approach is the ability of researchers to address the spatial heterogeneity of urban ecosystems; i.e. the development and dynamics of spatial heterogeneity and the influences of spatial patterns on cycles and fluxes of critical resources (e.g. energy, materials, nutrients, genetic and nongenetic information, population, labor, and capital). An important question in this context is how differential access to and control over critical resources affect the structure and function of urban ecosystems.To address this heterogeneity, we illustrate a human ecosystem and landscape approach and how the concept of social differentiation can be applied spatially at different scales with a case study from our research in Baltimore, Maryland. Further, we identify different methods, tools, and techniques that can be used for an integrated, urban ecosystem approach.     

Marriage migration,a neglected form of long-term mobility: a case study from Ilorin,Nigeria

"This article examines the evidence for and possible significance of marriage migration in and around the city of Ilorin, the capital of Kwara State, Nigeria, which has a population of about 400,000." The study "reveals a movement of rural women to marry into wealthy polygymous compounds in the city and the return of some of these women to their rural natal compounds later in life. This movement may be an explanation for the high proportion of women in indigenous towns, and perhaps also in some newer medium-sized settlements. It can also be seen as a reflection of the unequal and exploitive relationship between the towns and their rural hinterland."     

Bequests and family traditions: the case of nineteenth century France

Like father, like son: is the bequest behavior of children “inherited” from that of their parents? Most economic models (altruistic, paternalistic or exchange models) postulate that bequest behavior does not depend per se on parents’ behavior. Yet because of data limitations, few empirical studies have analyzed the link between bequests left and inheritances received. In this paper, we evaluate the effect of inheritance relative to lifetime income on the amount that individuals bequeath, in the case of France. This study uses original historical data including wealth genealogies covering the nineteenth and first half of the twentieth centuries for the Loire Inférieure département. Empirical evidence suggests that the propensity to bequeath is much greater for inheritance than for human resources: a deceased having inherited twice the average wealth leaves 35–60 % more to his own heirs that the average for his generation. In nineteenth century France, bequests are explained more by inheritance received than by personal savings per se.