Forest fragmentation as an economic indicator

Despite concern over the ecological consequences of conversion of land from natural cover to anthropogenic uses, there are few studies that show a quantitative relationship between fragmentation and economic factors. For the southside economic region of Virginia, we generated a surface (map) of urbanization pressure by interpolation of population from a ring of cities surrounding the region. The interpolated map showed a geographic gradient of urbanization pressure or demand for land that increased from northwest to southeast. Estimates of forest fragmentation were moderately correlated with the geographic gradient of urbanization pressure. The fragmentation-urbanization relationship was corroborated by examining land-cover change against the urbanization map. The geographic gradient in land-cover change was strongly correlated with the urbanization pressure gradient. The correspondence between geographic gradients in land-cover change and urbanization pressure suggests that forest fragmentation will occur at a greater rate in the eastern portion of the southside economic region in the future.     

The use of gradient analysis studies in advancing our understanding of the ecology of urbanizing landscapes: current status and future directions

Over the past decade, the urban–rural gradient approach has been effectively used to study the ecology of cities and towns around the world. These studies have focused on understanding the distribution of plants and animals as well as ecosystem processes along gradients of urbanization that run from densely urbanized inner city to more rural exurban environments. We reviewed 300 papers investigating urbanization gradients that were published in peer-reviewed journals between 1990 and May 2007. Sixty-three percent of the papers investigated the distribution of organisms along urbanization gradients. Only five papers addressed the measures used to quantify the urbanization gradient itself. Within the papers addressing the distribution of organisms, 49% investigated the responses of birds to urbanization gradients, and <10% of the papers investigated more cryptic organisms. Most of these studies utilized a variety of broad measures of urbanization, but future advances in the field will require the development of some standardized broad measures to facilitate comparisons between cities. More specific measures of urbanization can be used to gain a mechanistic understanding of species and ecosystem responses to urbanization gradients. While the gradient approach has made a significant contribution to our understanding of the ecology of cities and towns, there is now a need to address our current knowledge gaps so that the field can reach its full potential. We present two examples of research questions that demonstrate how we can enhance our understanding of urbanization gradients, and the ecological knowledge that we can obtain from them.     

张承地区城镇化与生态系统服务协调关系空间分异研究

为了探究城镇化水平与生态系统服务价值的关系，利用综合指数法、价值当量法等方法测算2010、2015、2018年张承地区生态系统服务价值和城镇化水平，并运用空间自相关分析法、排序分析法、弹性系数等研究城镇化与生态系统服务价值的空间相关性特征、相关性强弱和协调关系。结果表明：(1)研究期间，张承地区生态系统服务价值呈现降低趋势，减少7.47×10⁸元。(2)研究期间张承地区城镇化水平总体不高，城镇化综合指数的平均值由0.14上升至0.25。(3)县域协调关系最为显著的是极不协调发展，极不协调发展的县区占50%;尚义县处于协调发展状态；桥东区、桥西区等区域处于冲突状态，其余县区处于潜在威胁状态。(4)张承地区生态系统服务价值与城镇化水平之间存在空间负相关关系，不同县区的城镇化水平多度值位序与生态系统服务价值多度值排序存在显著差异。研究结果有利于进一步丰富城镇化与生态系统服务价值的相互作用理论。     

Aspects influencing the selection of representative urbanization measures to quantify urban–rural gradients

The quantification of urban–rural gradients using urbanization measures has become standard practice in many urban ecological studies. Nonetheless, the choice of urbanization measures for a specific urban gradient still remains problematic. Increasing numbers of papers stress the importance of comparative urban ecological research, in an attempt to contribute to an understanding of the ecology ‘of’ cities. This implies that research in diverse urban areas globally should be comparable. This study follows an approach to quantify the urban–rural gradient in Klerksdorp previously followed in Melbourne, Australia with the goal to help elucidate the viability of creating a standard set of urbanization measures that is useful across continents. Satellite imagery and spatial analysis were used to calculate the values of 12 urbanization measures across a 900 km² landscape grid. Principal components analysis is commonly used to identify smaller subsets of measures to quantify urban–rural gradients. The results of this study indicate that factor analysis is more suitable than principal components analysis and ideal in identifying these independent measures of urbanization. The factor analysis revealed that landscape structure and demographic attributes are both essential characteristics of a city that needs to be accounted for in the choice of urbanization measures. Additionally, we identified seven aspects influencing the direct comparison of cities, namely: scale of analysis, spatial resolution, classification typology, accuracy of input data, specific measure equations, the type of statistical analysis and the habitat context. These aspects must be taken into consideration and resolved before effective comparative gradient research between cities can be achieved.     

Peri-urbanization may vary with vegetation restoration: A large scale regional analysis

Over that past decade, ecological restoration practices have expanded globally. However, the effectiveness of ecological restoration depends on the complex interactions of various natural and socioeconomic factors, about which there is limited scientific understanding and thus provides an important research frontier. This paper analyzed the relationship between regional scale vegetation restoration and the process of urbanization using the Loess Plateau of China as a case study. This region has experienced both rapid urbanization and a high number of vegetation restoration activities. Urbanization and vegetation restoration can be considered as extremes on the spectrum of environment preservation activities. Three separate spatial correlation analyses between urbanization and vegetation restoration were identified, resulting in: 1) insignificant correlations in saturated urban areas; 2) significant negative correlations in peri-urban areas; and 3) significant positive correlations in undeveloped areas. The relationship between urbanization and vegetation restoration is thus stage-dependent. Impacts of urbanization on vegetation degradation has improved but has not been fully addressed by large scale vegetation restoration. Regardless of whether the county or grid scale is used, peri-urbanization was found to be the critical factor affecting the effectiveness of vegetation restoration over both time and space. Therefore, peri-urbanized areas are viewed as priorities for improving the coupling of urban development and vegetation restoration.     

河北省新型城镇化与土地生态安全耦合协调分析

以河北省为研究区域，以新型城镇化与土地生态安全耦合协调度为研究对象，运用耦合协调发展模型和空间自相关等分析方法测算了2005-2015年间河北省新型城镇化与土地生态安全耦合协调度，探究其空间集聚特征。研究结果表明：(1)河北各城市新型城镇化与土地生态安全耦合协调水平不存在耦合失调的情况，区域间耦合协调发展水平存在较大差异，大部分主要处于初级协调发展类型，仅有唐山、石家庄在2015年达到了良好协调发展类型。河北省新型城镇化与土地生态安全耦合协调度存在显著的空间正相关。(2)空间集聚类型上，绝大多数城市属于不显著类型区，高-高类型区、低-低类型区涉及的城市数量少。2005年仅有廊坊市处于高-高类型区、张家口市处于低-低类型区；2010年无城市处于高-高类型区，承德市、邢台市处于低-低类型区；2015年仅有秦皇岛市处于高-高类型区、无城市处于低-低类型区。研究可为其他地区推进城市化进程与提高土地生态安全水平，促进二者协调发展提供一定理论依据。     

Spatiotemporal pattern of urbanization in Shanghai, China between 1989 and 2005

Quantifying the spatiotemporal pattern of urbanization is necessary to understand urban morphology and its impacts on biodiversity and ecological processes, and thus can provide essential information for improving landscape and urban planning. Recent studies have suggested that, as cities evolve, certain general patterns emerge along the urban–rural gradient although individual cities always differ in details. To help better understand these generalities and idiosyncrasies in urbanization patterns, we analyzed the spatiotemporal dynamics of the Shanghai metropolitan area from 1989 to 2005, based on landscape metrics and remote sensing data. Specifically, the main objectives of our study were to quantitatively characterize the spatiotemporal patterns of urbanization in Shanghai in recent decades, identify possible spatial signatures of different land use types, and test the diffusion coalescence hypotheses of urban growth. We found that, similar to numerous cities around the world reported in previous studies, urbanization increased the diversity, fragmentation, and configurational complexity of the urban landscape of Shanghai. In the same time, however, the urban–rural patterns of several land use types in Shanghai seem unique—quite different from previously reported patterns. For most land use types, each showed a distinctive spatial pattern along a rural–urban transect, as indicated by landscape metrics. Furthermore, the urban expansion of Shanghai exhibited an outward wave-like pattern. Our results suggest that the urbanization of Shanghai followed a complex diffusion–coalescence pattern along the rural–urban transect and in time.     

Arthropod assemblages and functional responses along an urbanization gradient: A trait-based multi-taxa approach

Urbanization causes considerable alteration across a wide range of ecosystem functions at regional and global scales. These changes could be key drivers of habitat stability and ecosystem services in urban greenspaces. The aim of this study was to test the influence of urbanization on taxonomic and functional diversities of arthropods of different trophic levels. We collected predator spiders, polyphagous rove beetles, and decomposer woodlice along a rural-suburban-urban gradient by litter sifting. Neither the taxonomic, nor the functional diversity (Rao’s quadratic entropy) using a morphological trait (body size) and ecological traits (habitat affinity, humidity preference, and disturbance sensitivity) of the spiders were significantly different along the urbanization gradient. For rove beetles, taxonomic diversity was significantly higher in rural sites compared to suburban and urban ones, while functional diversity did not differ significantly between sites. Both the taxonomic and the functional diversities of woodlice were significantly higher in the rural sites than in the suburban or urban sites. Detrended canonical correspondence analysis also showed that urbanization did not cause considerably changes in composition of spider assemblages, while rove beetle and woodlouse assemblages showed clear separation between rural and urban sites. This study pointed out that trophic levels may be a crucial driver of the responses to urbanization. Our results suggest that urbanization has a less harmful effect on predator spiders, as they can easily recolonize the managed urban greenspaces. Contrarily, recolonization of arthropods at lower trophic levels (rove beetles and woodlice) into the urban habitats is considerably restricted.     

Effects of urbanization on ground-dwelling spiders in forest patches,in Hungary

Effects of urbanization on ground-dwelling spiders (Araneae) were studied using pitfall traps along an urban-suburban–rural forest gradient in Debrecen (Hungary). We found that overall spider species richness was significantly higher in the urban sites compared to the suburban and rural ones. The increased diversity was due to the significantly more open-habitat species in the assemblages at the urban sites. This suggests that species from the surrounding matrix (grasslands and arable lands) penetrated the disturbed urban sites. The ratio of forest species was significantly higher in the rural sites than in the suburban and urban ones, suggesting that forest species are indeed sensitive to the disturbance caused by urbanization. Canonical correspondence analysis revealed that the species composition changed remarkably along the urbanization gradient. Open-habitat spiders were associated with the urban sites of higher ground and air temperature. Forest spiders were characteristic of the rural sites with higher amount of decaying woods. Our findings suggest that the overall diversity was not the most appropriate indicator of disturbance; species with different habitat affinity should be analyzed separately to get an ecologically relevant picture of the effect of urbanization.     

Multifunctionality in practice: Measuring differences in urban woodland ecosystem properties via functional traits

The ability of urban woodlands to regenerate and provide ecosystem services depends on the maintenance of a range of ecosystem functions and processes (i.e. multifunctionality). Many conservation decisions are made by local land stewards and rely on taxonomic characterization of woodlands to infer ecosystem properties, but there is reason to doubt this approach. Can functional traits provide better information on ecosystem multifunctionality? We compare three methods for capturing differences in urban woodland multifunctionality. We ask whether differences in (1) species composition, (2) traits associated with urbanization (urbanization markers) or (3) traits associated with specific ecosystem properties (functional markers) best capture actual differences in colonisation, water infiltration and decomposition in woodlands across a rural-urban gradient (Montreal, Canada). We use Procrustes superimposition and Mantel tests to compare the fit of each method. We propose the functional Mahalanobis distance to measure the distance of an urban woodland from a reference range of multifunctionality.All three methods were significantly congruent with actual differences in ecosystem multifunctionality, but the strength of the rank-order correlations varied widely. Species composition and urbanization markers had a similar but weak correlation with differences in multifunctionality. Importantly, the mismatch between species composition and multifunctionality increased with urbanization. Functional markers captured ecosystem multifunctionality better than either species composition or urbanization markers.Commonly used species- and general trait-based approaches were poor measures for multifunctionality in our urban woodlands. Functional markers rely on vegetation inventories already routinely collected by land stewards and openly available trait information: they may provide a cost-effective way of capturing multifunctionality in urban systems. More broadly, the functional Mahalanobis distance provides a quantitative measure of site-level multifunctionality that allows land stewards to compare woodlands with a reference range of variability in a format that can directly inform conservation decisions.     

Net primary productivity (NPP) dynamics and associated urbanization driving forces in metropolitan areas: a case study in Beijing City,China

Context

Eco-environmental effects of urbanization are a focus in landscape ecology.

Objective

The influences of population, economic and spatial development during the urbanization process in Beijing City, China on net primary productivity (NPP) were analyzed. The responding mechanism of NPP in different urbanization stages was also examined to develop advice about eco-environmental sustainability of urban development.

Methods

Using the Carnegie Ames Stanford Approach model, we estimated NPP. Using linear regression and polynomial regression analysis, we analyzed NPP responses to stages of urbanization.

Results

High NPP areas were located in northeast Yanqing, northwest Miyun, northern Huairou and Pinggu. The distribution of NPP generally occurred in the following order from high NPP to low NPP: outer suburbs, inner suburbs, encircled city center, and inner city. Because of the heat island effect in winter, the estimated NPP in the encircled city center and inner city was higher in 2009 than in 2001. There was a negative correlation between NPP and both economic and spatial urbanization, but an increase in population did not necessarily lead to an immediate decrease in NPP. An analysis of NPP dynamics in five kinds of urban development zones showed that urbanization resulted in a lasting and observable loss of NPP over time and space, although there was some promotion of NPP in highly urbanized zones.

Conclusion

There are three stages in the response of NPP to urbanization: damage stage, antagonistic stage, and coordination stage. The stage threshold depends on local eco-environmental management and urban planning interventions.

     

景观设计在推进农村城镇化中的角色价值分析

城镇化是当今社会发展的必然趋势,针对城镇化进程中可能出现的环境问题开展景观设计具有较好的现实理论指导意义。城镇化是一个正在进行中的实践活动,我国广大农村有的已经开展新型农村社区建设,有的还保持着传统的风貌。分析城镇化进程中景观设计的缺失及其现状,提出景观设计在推进城镇化进程中可以发挥作用的方面。     

Urban-rural and temporal differences of woody plants and bird species in Harbin city,northeastern China

Urbanization has been greatly accelerated by the economic growth in China, while its possible effects on woody plants, bird species and their associations are not well defined yet. Here, we analyzed urban-rural gradients (landscape level: urban-farmland-forest-natural reserves; city level: ring road and urban build-up history) and temporal data (1955–1980–2014 for woody plants; 1980s–2010 s for birds) in Harbin city, China, to investigate the changes in the composition and diversity of woody plants and birds during urbanization. Both landscape gradient and temporal data confirmed that urbanization had the function of species conservations with sharp increases of alien species and tropical type plants. In the case woody species, 60-yr urbanization in Harbin had induced increases of 9 families and 17 genera, and there were 7–20 more families, 12–35 more genera, 1.6–2.6 higher Margalef richness in urban areas than those in nature reserves and local forest farms; Increases in alien species (4-fold in 60-yr urbanization; 21% in urban area vs <2% for non-urban region) and tropical type plants (1.6-fold in 60-yr urbanization; temperate/tropical ratio at 1.2 in urban area vs >1.6 in non-urban area) were mainly responsible for these compositional changes, which can be proved by their significant correlations. Moreover, moderate disturbance had peak values in alien species, tropical type plants, Shannon-wiener diversity, Margalef richness index and Pielou evenness index, and both ring road- and buildup history gradients showed the similar tendency. Compared with those in 1980s, forest- and eurytopic-habitats birds increased 9–11 species (23–39%), and omnivorous, insect-eating, and phytophagous bird increased 5–9 species (14.1–29.4%) in those in 2010s, indicating that bird temporal changes were closely related with the changes in urban forests owing to food supply and habitat provision. Our findings could provide data for biodiversity evaluation of urbanization effects, and is also useful for ecological re-construction of local cities in China.     

The role of urban habitats in the abundance of red squirrels (Sciurus vulgaris,L.) in Finland

Because the amount of urban areas has increased, it is important to investigate the abundance of wildlife species in relation to urban environments. Analyzing the impact of urbanization on the presence of forest-dwelling mammals is of interest due to the possible effects of urbanization on human-wildlife relationships and urban biodiversity. The Eurasian red squirrel (Sciurus vulgaris) is a declining forest species, and its occurrence in urban environments has been inadequately studied. The loss and fragmentation of forests due to urbanization may be detrimental for squirrels, whereas the abundant and predictable food resources and the low number of natural predators in urban areas may encourage squirrels to invade towns. We used large-scale data collected by volunteer bird watchers along a 950 km south-north gradient to study whether the winter abundance of squirrels in Finland is dependent on urbanization, while controlling for effects of habitat type, food abundance (spruce cone crop; number of winter feeding sites), predator abundance (northern goshawk, Accipiter gentilis; feral cat Felis catus), season and latitude. We found that squirrel abundance increased with human population density, number of feeding sites and spruce cone crop and decreased with latitude and season. Feral cats showed weak negative connection with squirrel numbers, but there were no effect of goshawks. Relative squirrel abundance was approximately twice as high in urban habitats than in forests. Artificial feeding rather than a low number of predators may attract squirrels in urban environments. Planting spruce trees in urban environments will also benefit squirrels. Our results indicate that urban areas are an important habitat for the red squirrel even along the northern edge of their distribution range, where natural forest areas are still widespread. We conclude also that a citizen science −based bird survey protocol associated with mammal surveys seems to be a good large-scale monitoring method to study the urbanization of squirrels.     

Native plants on experimental urban green roofs support higher community-level insect abundance than exotics

Urbanization is one of the multiple factors leading to global insect declines. As urbanization grows, green roofs represent a nature-based solution that could provide habitat for plants and animals within cities. Several characteristics of green roofs could enhance insect biodiversity. Nevertheless, little is known about the effects of plant origin on insect abundance from a multi-taxa perspective. Thus, our main goal was to evaluate the effects of plant origin, local resources, and urbanization level on green roofs’ overall insect abundance, the abundance of different taxonomic orders, and community composition. Using experimental green roofs, we compared insect communities between native and exotic plants across an urbanization gradient, in Córdoba city, central Argentina. On the roofs of 30 houses, we installed two blocks of a modular extensive green roof system, with either native or exotic plant species (6 species each). In March 2019, we used yellow pan traps and pitfall traps (N = 360) to sample insects and measured flower abundance and plant cover at each plant treatment. The urbanization level of each house was estimated by the Normalized Difference Vegetation Index (NDVI), the Normalized Difference Built-up Index (NDBI), and the Land Surface Temperature (LST). A total of 35,257 insects from 12 orders were registered, with Diptera, Hymenoptera, and Hemiptera as the dominant groups. Native plants supported significantly higher total insect abundance on both types of traps, independently from the urbanization level, flower abundance, or plant cover of each roof. The abundance of most of the taxonomic orders was higher in natives as well, but particular effects of the covariables were detected for certain groups. In addition, plant origin was an important factor for insect composition. Our results highlight that green roof design should prioritize native plants to enhance insect conservation while achieving more sustainable cities.     

Multi-scale responses of bird species to tree cover and development in an urbanizing landscape

Landscape change is an ongoing process for even the most established landscapes, especially in context to urban intensification and growth. As urbanization increases over the next century, supporting bird species’ populations within urbanizing areas remains an important conservation challenge. Fundamental elements of the biophysical structure of urban environments in which bird species likely respond include tree cover and human infrastructure. We broadly examine how tree cover and urban development structure bird species distributions along the urban-rural gradient across multiple spatial scales. We established a regional sampling design within the Oak Openings Region of northwestern, Ohio, USA, to survey bird species distributions across an extensive urbanization gradient. Through occupancy modeling, we obtained standardized effects of bird species response to local and landscape-scale predictors and found that landscape tree cover influenced the most species, followed by landscape impervious surface, local building density, and local tree cover. We found that responses varied according to habitat affiliation and migratory distance of individual bird species. Distributions of short-distance, edge habitat species located towards the rural end of the gradient were explained primarily by low levels of urbanization and potential vegetative and supplemental resources associated with these areas, while forest species distributions were primarily related to increasing landscape tree cover. Our findings accentuate the importance of scale relative to urbanization and help target where potential actions may arise to benefit bird diversity. Management will likely need to be implemented by municipal governments and agencies to promote tree cover at landscape scale, followed by residential land management education for private landowners. These approaches will be vital in sustaining biodiversity in urbanizing landscapes as urban growth expands over the next century.     

Quantifying the speed, growth modes, and landscape pattern changes of urbanization: a hierarchical patch dynamics approach

Urbanization transforms landscape structure and profoundly affects biodiversity and ecological processes. To understand and solve these ecological problems, at least three aspects of spatiotemporal patterns of urbanization need to be quantified: the speed, urban growth modes, and resultant changes in landscape pattern. In this study, we quantified these spatiotemporal patterns of urbanization in the central Yangtze River Delta region, China from 1979 to 2008, based on a hierarchical patch dynamics framework that guided the research design and the analysis with landscape metrics. Our results show that the urbanized area in the study region increased exponentially during the 30 years at the county, prefectural, and regional levels, with increasing speed down the urban hierarchy. Three growth modes—infilling, edge-expanding, and leapfrogging—operated concurrently and their relative dominance shifted over time. As urbanization progressed, patch density and edge density generally increased, and the connectivity of urban patches in terms of the average nearest neighbor distance also increased. While landscape-level structural complexity also tended to increase, the shape of individual patches became increasingly regular. Our results suggest that whether urban landscapes are becoming more homogenous or heterogeneous may be dependent on scale in time and space as well as landscape metrics used. The speed, growth modes, and landscape pattern are related to each other in complicated fashions. This complex relationship can be better understood by conceptualizing urbanization not simply as a dichotomous diffusion-coalescence switching process, but as a spiraling process of shifting dominance among multiple growth modes: the wax and wane of infilling, edge-expansion, and leapfrog across the landscape.     

The urbanization of wildlife management: Social science, conflict, and decision making

Increasing urbanization of rural landscapes has created new challenges for wildlife management. In addition to changes in the physical landscape, urbanization has also produced changes in the socio-cultural landscape. The greater distancing from direct interaction with wildlife in urbanized societies has led to the emergence of a culture whose meanings for wildlife are less grounded in the utilitarian/instrumental orientation of rural agrarian systems. Urban perspectives on wildlife are comprised of more highly individualized emotional/symbolic values. This shift creates two problems with respect to managing wildlife in an urbanizing landscape. First the increased diversity in values and meanings increases the likelihood for social conflicts regarding wildlife management while at the same time making socially acceptable resolutions more intractable. This in turn requires fundamental changes in decision-making paradigms and the research approaches used to inform decision making. Second, as remaining rural communities feel the pressures of urbanization, wildlife conflicts become conflicts not just over wildlife but conflict over larger socio-political concepts such as equity, tradition, private property rights, government control, power, and acceptable forms of knowledge. This paper examines the wildlife management implications of changes associated with increasing urbanization and employs two case studies to illustrate these issues. First a study of a controversy over urban deer management provides insights into how to map conflicting values and search for common ground in an urban culture with increasingly individualistic values for wildlife. Specifically, the analysis illustrates that common ground may, at times, be found even among people with conflicting value systems. The second case study examined a ranching community faced with predator reintroduction. This case study illustrates tensions that occur when the community of interest (i.e. a national public) is broader than the community of place in which the problem occurs. In this latter situation, the debate centers around more than just different views about the rights of animals. It also entailed the rights of individuals and communities to decide their future. The conclusion discusses the need for wildlife institutions to adapt their underlying decision making philosophy including the way science is integrated into decision making processes in light of the changes in social context caused by urbanization.     

Responses of anuran communities to rapid urban growth in Shanghai,China

Urbanization affects amphibian communities through habitat loss, fragmentation, and degradation of habitat quality. The effects of these changes in habitat at different scales vary depending on the sensitivity of individual species. We assessed the breeding distribution of anurans along an urban–rural gradient in Shanghai, China, a region experiencing intensive urbanization. Our results showed that urban density had a significantly negative influence on the overall anuran abundance and diversity and that the responses of individual species to urbanization varied. Pond age was an overall predictor in models describing the responses of Pelophylax nigromaculatus, Fejervarya multistriata, and M. fissipes and total anuran abundance. The quality of habitat at a pond was also important, and the high abundance of Bufo gargarizans and Pelophylax plancyi was associated with ponds with aquatic vegetation coverage. Urban density showed strong negative effects on B. gargarizans, total anuran abundance, and species richness. The broad-scale landscape variables associated with forests, agricultural fields, and wetlands surrounding breeding ponds have been shown to affect anuran abundance and species richness. The response of individual species, total abundance, and species richness to urbanization reflected differences in their ecological requirements. We quantified the effects of urbanization on frogs in a rapidly urbanizing region, and our results demonstrated that both multi-spatial and temporal variables affect anurans in Shanghai. Our results emphasized the importance of anuran conservation planning in urbanized areas to preserve and/or restore terrestrial habitat and to improve connectivity between ponds and other wetlands.     

Effects of landscape urbanization on magpie occupancy dynamics in France

Responses of species to landscape modifications are generally documented through their distribution at a given time along an intensity gradient of land transformation. By focusing on patterns, we are limited to infer ecological processes occurring within a system and its response to environmental disturbances which can further change over time. Using diachronic datasets at the scale of France, we analyzed the spatial responses of the black-billed magpie, which has recently colonized cities, to landscape urbanization. This study applied recently developed statistical approaches incorporating detection uncertainty of the magpie, based on the capture-recapture statistical framework. We tested whether, and how, extinction and colonization mechanisms influenced variations of magpie occupancy from 2001 to 2005. In addition, we assessed the importance of the recent urbanization of the French countryside in determining population dynamics. Overall, our analysis proved that the proportion of urban areas and recent urbanization in France led to an increase in the probability of magpie occupancy. Unexpectedly, the species is concomitantly disappearing from the countryside, leading to a rapid change in the distribution of the species. This study stressed the importance of incorporating detection uncertainty in inference process about spatial dynamics. Overall, we show how useful it is to account for the dynamic evolution of the landscape in ecological studies.