Temporal effects on biodiversity and composition of arthropod communities along an urban–rural gradient

Global urbanization is rapidly increasing, yet the prevalence of single order and time point studies likely miss important temporal effects of urbanization on entire communities. We studied three sites along a rural–urban gradient in the Seattle metropolitan area with three sampling periods from 2009–2011 to examine how arthropod communities respond to increasing levels of urbanization in a similar habitat type through time. Consistent with previous studies, urban areas contained altered environmental conditions relevant for litter arthropods, and arthropod biodiversity decreased with urbanization. However, urban arthropod biodiversity was not influenced by environmental measures, supporting the idea of an “urban-filter”. Urbanization was not a factor influencing how communities responded to the effect of time, suggesting that other factors (e.g. disturbance) may ultimately be more important for determining patterns of biodiversity through time in urban areas. Finally, our study illustrates urbanization forces can structuring entire arthropod communities similarly through time, having important consequences for our understanding of urbanization’s temporal effects and indirect influence on community interactions and ecosystem processes. As the effects of urbanization will inevitably vary through time, we suggest that multiple time point studies are required to increase our ability to accurately describe arthropod community responses to increasing urbanization.     

Long-term urbanization effects on tree canopy cover along an urban–rural gradient

Urban forestry can benefit from improved knowledge of urbanization??s effects on tree canopy cover (TCC), a prominent urban forest indicator. This study examined changes in TCC over a long time frame, with respect to land cover (LC) changes, and across municipal boundaries. Specifically, I used air photos at 14 dates from 1937 to 2009 to develop an exceptionally long record of TCC change in Minnesota??s Twin Cities Metropolitan Area. During the study period overall TCC nearly doubled from 17% to 33% while the proportion urban land cover rose by 47%, highlighting the opportunity for substantial TCC gains following urbanization in previously agricultural landscapes, even in regions that were forested prior to European settlement. Results demonstrate that more intensely developed sites generally had lower TCC, and older urban sites had higher TCC. Modern TCC was not adequately characterized by linear distance along the urban?Crural gradient, but instead peaked near the center of the gradient where mature residential neighborhoods are prevalent. Compared to other land cover changes, urbanization events caused the highest rate of immediate TCC loss (9.6% of events), yet urban areas had the second highest TCC (>35%) in 2009, indicating that urban land gained TCC relatively efficiently following development. The results of this study provide new historical context for urban forest management across an urban?Crural gradient, and emphasize the need to consider ecological legacies and temporal lags following land cover changes when considering TCC goals in urban settings.     

Variability of agroecosystems and landscape service provision on the urban–rural fringe of Wuhan,Central China

Urban Ecosystems - Urbanization drives changes in peri-urban farmland use which probably affects the spatial pattern of landscape service provision. This study charts patterns in these services and...     

Disentangling an avian assemblages’ evolutionary and functional history in a Chihuahuan desert city

Urban Ecosystems - Urban green spaces have been shown to be important hotspots of biodiversity in cities of temperate and humid/semihumid tropical ecoregions. Nonetheless, whether this pattern...     

Canopy trees in an urban landscape – viable forests or long-lived gardens?

Seedling recruitment shapes tree communities, including those found in altered landscapes such as urban forests. However, little data exists on local- and broad-scale tree seed immigration and recruitment in these communities. Interspecific competition and seed predation are two major causes of recruitment failure for plants. In North American urban forests, these pressures may be exacerbated by an altered disturbance regime and prevalent invasive species combined with dense populations of rodents and browsers. Preliminary investigation in an urban forest on the eastern shore of Lake Erie indicated very low long-term tree seedling recruitment in the mature canopy stands. Our competing hypotheses were that seed establishment (habitat suitability) and seed limitations (seed availability) explained the tree recruitment failure. We tested seed establishment using field experiments (burning and vertebrate herbivore exclosures) and seed limitation by introducing native tree seeds. Moreover, we tested also seed limitation by examining local and regional seed input using seed traps. We found that seedling recruitment increased significantly with experimental reductions in predators and competitors, suggesting strong biotic establishment limitations in the urban forest. In addition, seed rain correlated significantly with immediately proximate parent plants, but no species arrived beyond what occurs within 50 m of the experimental plots. Essentially, then, the existing canopy species are not replacing themselves and extant seeds are not immigrating to replace them. At the patch scale, habitat quality, particularly seed predation and browsing, as well as competition from nonnative understory shrubs, constrained native tree recruitment in the urban forest. At the landscape scale, the evidence of poor long-term seed recruitment and the lack of long-distance seed input also suggest low native tree seed availability. The tree recruitment failure suggests that, in the absence of active management, this urban forest may eventually convert to an invasive-species dominated urban shrubland.     

Farm persistence and adaptation at the rural–urban interface: Succession and farm adjustment

Despite assumptions that agriculture will automatically go into a mode of decline at the Rural Urban Interface (RUI), official statistics suggest that agriculture as a whole remains a strong (and in some cases a growing) industry in many U.S. RUI counties. RUI scholars have acknowledged internal family dynamics can significantly influence farm persistence and adaptation strategies, however, few studies have sought to document the specific role succession has on farm structure at the RUI. Building off rural geography models of farm organization at the RUI and succession research embedded in rural studies we analyze interviews from 33 U.S. farm families to 1) explore the relationship between farm adaptation and succession at the RUI, and 2) examine how succession is related to the different types of enterprises found at the RUI (direct marketers vs. commodity producers) and the types of growth strategies these farm families implement. We find that families who can not identify an heir either disinvest or enter a static management mode. Among farm families who can identify an heir we identify a variety of horizontal and vertical growth strategies (expanding, intensifying, and entrepreneurial stacking) designed to achieve farm reproduction goals. We discuss the theoretical and policy related implications of this research.     

Juggling a “junk-food” diet: responses of an urban bird to fluctuating anthropogenic-food availability

Within highly urban systems, anthropogenic activity often fluctuates cyclically, e.g. between weekdays and weekends. Thus, urban species may regularly experience significant changes in human activity and anthropogenic food abundance over very short time scales. Knowledge of how urban birds cope with such fluctuations may improve our understanding of how some species exploit and thrive in urbanised habitats. In this study, we explore the consequences of highly fluctuating anthropogenic food for Red-winged Starlings Onychognathus morio at the University of Cape Town campus, South Africa. Here, high numbers of students (and therefore anthropogenic food resources) are present during weekdays in term time (high human presence “HHP” days). However, students are largely absent and food outlets closed during weekends and vacation periods (“LHP” days). Using focal observations and morning and evening weights of habituated colour-ringed starlings during the non-breeding season, we investigated how diet, behaviour and daily mass gain differed between HHP and LHP days. We hypothesised that anthropogenic food supply is beneficial to this city-dwelling species. We predicted that on HHP days starlings would consume overall more food and a greater proportion of anthropogenic food items, resulting in less time spent foraging and greater daily mass gain compared to LHP days. We found that on HHP days, starlings consumed more anthropogenic food, however overall food intake, and time budgets were similar to LHP days. Additionally, there was an indication that mass gain was greater on HHP days. Thus, starlings appear to cope with potential food shortage on LHP days by including more natural items in their diet.

     

Betterment and trust in a rural Ciskei village∗

During the 1960's government‐financed agricultural betterment schemes were introduced into several rural villages in the Keiskammahoek magisterial district of the Ciskei, ‘a self‐governing homeland in South Africa'’ (Quail, 1980).

The first part of this paper traces the planning and implementation of betterment in Cata village. Seen in terms of its own goal of creating a ‘stable rural peasantry’ the betterment scheme has not succeeded. However, the success of a betterment scheme should not be seen only in terms of material and socialbenefits, but also in terms of its ability to persuade the villagers of the desirability and value of betterment as such, to change attitudes. Here the scheme has scored only very limited success. The second part of the paper looks at the villagers‘¹ perceptions of the desirability and value of betterment as it was brought to them and considers the differences between their attitudes and those of officialdom.     

Continuity or rupture? Roma/Gypsy communities in rural and urban environments under post-socialism

The aim of the article is to contribute to existing research and debates on social change associated with the post-socialist transformation in Eastern and Central Europe. It does so by drawing attention to and examining the diversity of ways in which such change has been lived through and reflected upon by members of Roma (Gypsy) communities living in urban and rural environments. Drawing on ethnographic research amongst excluded and segregated Roma in the ‘ghettos’ of Czech cities and in rural ‘Gypsy settlements’ in the Slovak countryside, the author notes a striking difference between how members of these communities, belonging to the same extended families, lived through and reflect upon the post-socialist transformation. While the members of the Roma communities living in Czech cities perceive the post-socialist transformation as one of the most dramatic ruptures in their life trajectories, the rural Roma do not seem to have been affected as deeply and dramatically, and their life trajectories seem to be framed by different events than those directly associated with the market transition. The paper analyses and explains the social and historical conditions that (co)produce the sense of rupture or continuity in the life trajectories of members of Roma communities exposed to urban and rural environments.     

Youth transitions and interdependent adult–child relations in rural Bolivia

There are few studies which document youth transitions from school to work in rural areas of the majority world. This paper, based on ethnographic fieldwork in a rural community in Bolivia, considers how young people make decisions about different types of school-to-work transitions which include migrating to continue their formal education, working in the community, or seeking migrant work in the regional town or in neighbouring Argentina. The paper explores how young people negotiate structural constraints over their choice of transition, including the rural location, economic resources, parental attitudes and family background, gender, birth order, social networks and role models. Importantly the paper highlights that underlying young people's choice of transition are interdependent household relations. In the majority world, in this case in Bolivia, rural young people may achieve economic independence sooner than those in the minority world, but long-term family interdependence tends to be maintained throughout the life-course. This paper suggests that the notion of negotiated interdependence is a more appropriate way to understand youth transitions and relations between young people and adults in rural areas of the majority world.     

Cemeteries and biodiversity conservation in cities: how do landscape and patch-level attributes influence bird diversity in urban park cemeteries?

Urban Ecosystems - Cemeteries can help conserve biodiversity in urban landscapes, but their capacity to support native species is likely to be influenced by variables at different spatial scales....     

“People in Stockholm are smarter than countryside folks” – Reproducing urban and rural imaginaries in film and life

This article explores the celebrated film The Hunters (Swedish title: Jägarna) within the context of the discourse of Internal Orientalism. By juxtaposing a contemporary Swedish film with historical accounts and contemporary news media, I demonstrate how the film reworks and (re)produces representations of the rural North (Norrland), constructing stereotypes enmeshed with familiar and global genre-specific stereotypes of a traditional and intransigent population positioned in rural areas and a modern and progressive population in urban areas. This paper shows how the representation in popular culture becomes enmeshed with the representation in news media and politics and how this helps obscure geography, gender, ethnicity and class by way of positioning representations of the middle class in urban spaces and white male working class in rural spaces, and by way of constructing class as a choice of lifestyle or culture.     

Diet of the crowned eagle (Stephanoaetus coronatus) in an urban landscape: potential for human-wildlife conflict?

Urban Ecosystems - The study of diet is pivotal in understanding a species, particularly for quantifying a predatory raptors’ economic niche and potential for human-wildlife conflict. The...     

Mother–child and teacher–child relationships and their influences on Chinese only and non-only children's early social behaviors: The moderator role of urban–rural status

Investigations regarding the differences between Chinese only and non-only children primarily examine children's social behaviors, which are closely related to their early relationships with mothers and teachers. In recent years, the number of non-only children born in urban areas has increased because of the softening of the One-Child Policy, which leads to the distribution of non-only children shifting from being primarily in rural areas to being in both urban and rural areas. The present study investigates the current characteristics and influences of mother–child and teacher–child relationships on Chinese only and non-only children's early social behaviors from the perspective of urban and rural differences. Data were obtained from 126 rural only children, 94 rural non-only children, 168 urban only children and 155 urban non-only children from 38 semi-urban kindergartens in Beijing, China. Hierarchical multiple regression analyses found that mother–child closeness positively predicted children's social skills particularly in non-only children, whereas mother–child conflict positively predicted internalizing behavior problems in all four groups. Teacher–child conflict negatively predicted children's social skills most strongly in urban only children. Teacher–child conflict aggravated rural only children's, urban only children's and non-only children's internalizing and externalizing behavior problems, but mother–child closeness buffered rural only children's externalizing behavior problems. Findings underscore the importance for mothers to improve closeness, especially with rural only children, and for teachers to avoid conflict with both urban only and non-only children, as well as with rural only children.     

Outcomes of Parent–Child Interaction Therapy in an urban community clinic: A comparison of treatment completers and dropouts

This study examined outcomes of Parent–Child Interaction Therapy (PCIT) for 52 clinically referred children with oppositional behavior and their parents treated in an urban, community mental health clinic serving demographically (i.e., income level, ethnicity) diverse families. Standardized observations of parent–child interactions and parent reported measures of child behavior were collected at pre- and post-treatment. We addressed two primary research questions: (1) What are pre-treatment predictors of treatment completion? (2) What are treatment outcomes both for families who successfully completed PCIT and for treatment dropouts? Multiple logistic regression results showed a significantly greater likelihood of treatment completion related to higher parent education, male child gender, and two parent households. Among families who completed treatment, pre–post data demonstrated significant parent change in observed skill use and improvement in parent reported disruptive behaviors with medium to large effect sizes. Findings also documented early treatment benefits for families who completed the first phase of PCIT but dropped out in the final phase prior to meeting full graduation criteria. We discuss the findings and implications for community-based applications of PCIT in the context of community mental health's mission to provide effective treatment and maximize community access to services.     

Demography of a ground nesting bird in an urban system: are populations self-sustaining?

Urbanization poses threats to earth’s biota, and retention of remnant native habitat in protected areas within expanding urban boundaries may help alleviate threats to wildlife. However, it is unclear for nearly all nonsynanthropic (i.e., not benefiting from an association with humans) species whether vital rates in urban habitats can sustain populations or if populations persist only through immigration from outside the urban boundary. We conducted a three-year study of spotted towhees (Aves: Pipilo maculatus) breeding in four undeveloped parks in Portland, OR, USA, to measure park-specific seasonal reproductive output (F) and annual adult survival (S_A). We developed a stochastic model that combined F and S_A with an estimate of first-year survival to measure population growth rate (λ) in all parks assumed to be closed to immigration. F differed among parks but S_A did not. Relatively high F was possible because many pairs raised >1 brood/season. When combined with empirical estimates of survival through the 30-day period of post-fledging parental care (S_D = 0.645), only 2 of 4 parks were self-sustaining (i.e., λ > 1.0). However, S_D reflected substantial loss of fledglings to domestic cats (Felis catus). Assuming no loss to cats and either partial compensatory or additive mortality of fledglings substantially improved prospects of population persistence for declining (sink) populations. Moreover, allowing low levels of immigration to sinks reversed population declines in most parks even when vital rates were insufficient to maintain populations. Our results suggest that nonsynanthropic bird species can persist in urban landscapes, but also that offspring mortality in the post-fledging period may be a critical determinant of population viability.     

‘Green Tibetans’ in China: Tibetan geopiety and environmental protection in a multilayered Tibetan landscape

This article examines how certain Tibetans and Han Chinese converts to Tibetan Buddhism in Diqing Tibetan Autonomous Prefecture and Beijing are articulating various forms of environmental discourse, both in terms drawn from Tibetan ‘geopiety’, and/or from a Western model of environmental protection. In relation to these trends, I further explore how certain Tibetans are articulating their understanding of Tibetan Buddhism within an apparently localised context, while other Tibetans are more obviously appropriating from discourses originating in the West and/or wider Chinese society to become more ‘modern’, while at the same time retaining a conceptualisation of Tibetan Buddhism that is hybridised between traditional and modernist understandings. I also explore how some Han practitioners may seek to become more ‘Tibetan’ by endorsing localised forms of Tibetan Buddhism and/or ‘performing’ certain Tibetan modes of religiosity, while others, due in part to geographical distance from the Tibetan landscape and cultural context, endorse an understanding of Tibetan Buddhism which is more closely tied to discourses of environmental protection originating in the West. In both Tibetan and Han Chinese cases, informants reflect upon their own beliefs and identity by gazing at the Other (Tibetan, Han, or Westerner), and marking out differences and similarities between Self and Other.     

Identifying habitat sinks: a case study of Cooper’s hawks in an urban environment

We studied a population of Cooper’s hawks (Accipiter cooperii) in Tucson, Arizona from 1994 to 2005. High rates of mortality of nestlings from an urban-related disease prompted speculation that the area represented an ecological trap and habitat sink for Cooper’s hawks. In this paper, we used estimates of survival and productivity from 11years of monitoring to develop an estimate of the rate of population change, λ, for Cooper’s hawks in the area. We used a Cormack–Jolly–Seber approach to estimate survival of breeding hawks, and a stochastic, stage-based matrix to estimate λ. Despite the urban-related disease, the estimate of λ indicated that the area does not function as a habitat sink for Cooper’s hawks (= 1.11 ± 0.047; P = 0.0073 for the null of λ ≤ 1). Because data required to reliably identify habitat sinks are extensive and difficult to acquire, we suggest that the concept of habitat sinks be applied cautiously until substantiated with reliable empirical evidence.