The role of dispersal and local environment in urban land snail assemblages: an example of three cities in Central Italy

Ecologists increasingly appreciate the central role that urban biodiversity plays in ecosystems, however much urban biodiversity is neglected, especially some very diverse groups of invertebrates. For the first time in southern Europe, land snail communities are analysed in four urban habitats along a geographical gradient of three cities, using quantitative methods and assessing the relative roles of local environmental conditions (“distance from sea”, “distance from city centre”, “vegetation cover”) and spatial effects by principal coordinate analysis of neighbour matrices, redundancy analysis and variation partitioning. A total of 53 species was recorded, a richness similar to that of natural areas. At habitat level, species richness did not show a clear increasing trend from more to less urbanized habitats, but rather a homogeneous pattern. At city level, study areas hosted rather heterogeneous species assemblages and biotic homogenization did not seem to have any impact; indeed, only three species could be considered alien. Variation partitioning showed that land snail communities were mostly structured by environmental factors, even when spatial structures independent of measured environmental variables were included: “vegetation cover” and “distance from city centre” were the environmental variables that explained most of the variation in species composition. The lack of strong spatial structure also unexpectedly suggested that transport by humans aids dispersal of organisms with low mobility, which are usually limited by spatial constraints in natural environments. These results provide ecological and conservation implications for other invertebrate groups, suggesting to set priorities in management strategies that include habitat conservation at local scale.     

Relationships between landscape pattern metrics,vertical structure and surface urban Heat Island formation in a Colorado suburb

Change in land surface temperature (LST) due to urbanization is a critical influence on the ecohydrological function and human health in cities. Past research has emphasized land cover composition and planimetric landscape pattern as drivers of LST patterns, but there have been few empirical studies examining the effects of vertical structure on thermal variation in cities. We used agglomerative cluster analysis to group 5 ha grid cells with similar land cover composition from high-resolution land cover data for our Aurora, Colorado, USA study area. We then compared the importance of different planimetric landscape pattern metrics and lidar-derived vertical structure variables as predictors of LST estimated from Landsat 5 thermal band data for each group. Variation in LST between cluster groups was analyzed with landscape and vertical structure data using random forest regression models and conditional variable importance metrics. Cluster analysis produced 7 distinct groups differing in land cover composition, planimetric landscape pattern, and vertical structure. Clusters with greater tree cover and higher mean tree height were generally cooler, while the height difference between buildings and trees had high conditional variable importance in random forest regression models. We found that the specific planimetric landscape pattern and vertical structure metrics most important for individual clusters differed, suggesting that the relative importance of variables depends on land-use and land cover. Our results highlight the importance of including vertical structure in empirical analyses of urban LST.     

Effects of habitat and landscape quality on amphibian assemblages of urban stormwater ponds

Urbanisation is one of the most severe drivers of current global biodiversity loss and has contributed to severe declines in many amphibian species. The aim of this study was to determine whether artificial stormwater ponds, designed to control water flow, can act as refuges for amphibians in urban areas. Moreover, we analysed the influence of habitat and landscape quality on amphibian species richness of 46 stormwater ponds (STOPON) in comparison to 46 control ponds (CONTROL).Our study revealed that environmental conditions clearly varied between STOPON and CONTROL. The most pronounced differences were that STOPON were larger, shallower, sunnier, more isolated by streets and had a greater cover of built-up area and lower cover of arable land surrounding them. Nevertheless, the amphibian assemblages of STOPON and CONTROL were very similar. All nine amphibian species (including three threatened species) detected in this study were found in both pond types. Moreover, species richness (2.8 ± 0.2 vs. 2.3 ± 0.2) and the frequency of each species did not differ between STOPON and CONTROL. The only exception was Pelophylax spp., which occurred more regularly in STOPON. Both habitat and landscape quality affected amphibian species richness; however, the explanatory power of the habitat models was about twice as high as those of the landscape models.In conclusion, stormwater ponds play an important role for amphibians in urban areas. In comparison to CONTROL, the low landscape quality in the surroundings of STOPON seemed to be compensated by a higher habitat quality due to regular management.     

Rainfall events drive foraging choices by an urban coloniser

Using a seven-year data set of visitation of an inner city park by the Australian white ibis, we investigated whether rain events were correlated with ibis abundance in the park. The park is associated with high levels of anthropogenic food, but relatively low levels of natural food sources. For all magnitudes of rainfall tested, ibis abundance significantly decreased after a rainfall event, although stronger responses were associated with higher rainfall, with a 46% decline in ibis abundance following rainfall events of ≥60 mm. Average ibis abundance was higher during the dry, non-breeding period than during the breeding period, and variation associated with rainfall was particularly pronounced in the non-breeding period. However, the rainfall response was still evident in both periods. Results suggest that rainfall influences the ibis distribution in urban centres either by decreasing anthropogenic food supplied to the birds, forcing the birds to relocate to forage, or increasing the amount of natural food available elsewhere, or a combination of the two. Increased rainfall intensified the response by ibis, and our results demonstrate the importance of climatic processes on the behaviour of urban birds.     

Framing the tribal: ethnic violence in Northeast India

This article examines the framing of ‘ethnic conflict’ in Northeast India, focusing on militant groups and insurgency in the hill areas of Assam and a form of political violence known locally as ‘ethnic clashes’. The article argues that ‘ethnic clashes’ have become an institutionalized form of armed violence in the region, while ‘ethnic rivalry’ is a key diagnostic frame for conflict. As enactments and imaginaries of institutionalized violence, ‘ethnic clashes’ are a product of actors who hold stakes in representing armed political violence as a result of ‘ethnic conflict’ between rivaling tribal communities. The article looks at the representation of causes of conflict as well as the framing of acts of violence as key sites of contestation, and thus as integral aspects of the conflict. This raises questions about the feasibility of scholarly efforts to make sense of specific cases of conflict via generic categories such as the ‘ethnic conflict’.     

Truth and Indigenous Cosmopolitics in Shangrila

As this article shows, cadres involved in the ‘discovery’ of Shangrila in Yunnan were well aware of the fictional origins of the name. In arguments for changing the name of Zhongdian county to Xianggelila, scientific facts were coupled with literary truths about the Shangri-La of the 1930s novel Lost Horizon, grounded in material reality. In their efforts to make Shangrila meaningful locally, cadres associated Shangrila with the hidden land of Shambhala, appealing to a spiritual reality ultimately knowable only to visionaries. We can thus talk about three different logics of truth (scientific, literary and visionary) and two different realities (material and spiritual) of concern to the ‘making up’ of Shangrila.     

Mortality–fertility synergies during the demographic transition in the developed world

The classic theory used to explain the demographic transition assumes that mortality is the key explanatory variable influencing the decline in fertility. However, the empirical results obtained in what is known as the Princeton European Fertility Project have led many specialists to question this assumption. Using both national and provincial aggregated data for 25 countries over a long time span, the analysis reported in this paper found that mortality does indeed play a fundamental role in accounting for the main demographic changes that occurred both before and during the transitional period. Others’ research based on individual data has shown clearly that the number of surviving children was indeed an important factor for reproductive decisions. My analysis, using aggregated data, reached largely similar conclusions regarding the role of mortality in changing reproductive trends, via its impact on nuptiality and marital fertility at different stages of the demographic transition.     

Pool size and the sustainability of optimal risk-sharing agreements

We study a risk-sharing agreement where members exert a loss-mitigating action which decreases the amount of reimbursements to be paid in the pool. The action is costly and members tend to free-ride on it. An optimal risk-sharing agreement maximizes the expected utility of a representative member with respect to both the coverage and the (collective) action such that efficiency is restored. We study the sustainability of the optimal agreement as equilibrium in a repeated game with indefinite number of repetitions. When the optimal agreement is not enforceable, the equilibrium with free-riding emerges. We identify an interesting trade-off: welfare generated by the optimal risk-sharing agreement increases with the size of the pool, but at the same time the pool size must not be too large for collective choices to be self-enforcing. This generates a discontinuous effect of pool size on welfare.     

Neoliberalism and Austerity in Spain,Portugal and South Africa: The Revolution of Older Persons

ABSTRACT

In Portugal, Spain, and South Africa, there has been a noted anti-neoliberal resistance, marked by the significant participation of the older generation in protest movements. Changing demographics, the global financial crisis, unemployment, poverty, and the reliance of the family nucleus on the pensioner, coupled with neoliberal and austerity-based reductions to welfare programs, pensions, health, and social care, has caused the “silver revolution.” As a population group that is often considered to be less politically active and robust members of society, such resistance is a noteworthy moment in society that needs to be considered and responded to.     

Parents' involvement in care order decisions: a cross‐country study of front‐line practice

This article examines parents' involvement in care order decision‐making in four countries at one particular point in the care order process, namely, when the child protection worker discusses with the parents his or her considerations regarding child removal. The countries represent different child welfare systems with Norway and Finland categorized as ‘family service systems’ and the USA as a ‘child protection system’, with England somewhere in between. The focus is on whether the forms and intensity of involvement are different in these four countries and whether the system orientation towards family services or child protection influences practice in the social welfare agencies with parents. Involvement is studied in terms of providing information to parents, collecting information from parents and ensuring inclusion in the decision‐making processes. A vignette method is employed in a survey with 768 responses from child protection workers in four countries. The findings do not show a consistent pattern of difference regarding parental involvement in care order preparations that align with the type of child welfare system in which staff work. The goal in each child welfare system is to include parents, but the precise ways in which it is carried out (or not) vary. Methodological suggestions are given for further studies.