Emergy evaluation of food production in urban residential landscapes

To transform cities from heterotrophic into sustainable ecosystems many authors have called for increased food production, including home gardening, in urban areas. We conducted an emergy analysis of four model backyard landscape plots—a conventional ornamental landscape, an intensive organic garden, an edible landscape, and a forest garden—to assess the yield and sustainability of these systems. Data were collected during the 2001 growing season and extrapolated to make a five year projection. In the 2001 season, all plots had low Emergy Yield Ratios (EYR) of between 0.0003 and 0.17 and extremely low Emergy Sustainability Indices (SI). In the five year projection, all plots still had low EYRs of between 0.0008 and 0.33 and very low SIs. These low indices are due primarily to the high levels of economic inputs required for the installation and maintenance of these plots in an urban context. Analyses performed on larger systems (households, neighborhoods and cities) containing productive landscapes such as those studied here may produce different results. Installing food-producing landscapes in urban areas without altering the networks by which such landscapes are supplied, however, may not substantially alter the heterotrophic nature of cities.     

Potential impacts of emerald ash borer invasion on biogeochemical and water cycling in residential landscapes across a metropolitan region

Trees provide important ecological services in cities, yet the vulnerability of the urban forest to massive tree losses from pest outbreaks could threaten those services, with unknown environmental consequences. The outbreak of emerald ash borer is an imminent threat to the ash population in North America. In the Minneapolis?CSaint Paul, Minnesota, metropolitan area, ash trees are present in 50?% of residential landscapes in Ramsey and Anoka Counties. We used a large survey of household activities, a tree inventory, a Household Flux Calculator accounting tool, and a set of annual evapotranspiration measurements, to quantify the current carbon, nitrogen, and phosphorus storage in ash trees, the cycling of these elements, and the total evapotranspiration from ash trees in residential areas in the metropolitan region. Ash represented 6?% of the trees in residential areas and the removal of the entire ash population would correspondingly reduce net primary production and carbon sequestration by only a few percent and would have negligible effects on losses of nitrogen and phosphorus from residential landscapes. Similarly, the effects of ash loss on the hydrologic cycle would be minimal and would depend largely on management choices for the ground currently underneath ash tree canopies. Overall, the percentage change in biogeochemical and hydrological fluxes corresponded closely with the percent of the total urban tree population that was represented by ash, suggesting that areas with higher densities of ash would experience correspondingly larger effects. A hypothetical tree replacement scenario with similar broadleaf species was determined to be likely to re-establish the original biogeochemical and hydrological conditions once the replacement trees reach maturity.     

Ecosystem services in managing residential landscapes: priorities,value dimensions,and cross-regional patterns

Although ecosystem services have been intensively examined in certain domains (e.g., forests and wetlands), little research has assessed ecosystem services for the most dominant landscape type in urban ecosystems—namely, residential yards. In this paper, we report findings of a cross-site survey of homeowners in six U.S. cities to 1) examine how residents subjectively value various ecosystem services, 2) explore distinctive dimensions of those values, and 3) test the urban homogenization hypothesis. This hypothesis posits that urbanization leads to similarities in the social-ecological dynamics across cities in diverse biomes. By extension, the thesis suggests that residents’ ecosystem service priorities for residential landscapes will be similar regardless of whether residents live in the humid East or the arid West, or the warm South or the cold North. Results underscored that cultural services were of utmost importance, particularly anthropocentric values including aesthetics, low-maintenance, and personal enjoyment. Using factor analyses, distinctive dimensions of residents’ values were found to partially align with the Millennium Ecosystem Assessment’s categories (provisioning, regulating, supporting, and cultural). Finally, residents’ ecosystem service priorities exhibited significant homogenization across regions. In particular, the traditional lawn aesthetic (neat, green, weed-free yards) was similarly important across residents of diverse U.S. cities. Only a few exceptions were found across different environmental and social contexts; for example, cooling effects were more important in the warm South, where residents also valued aesthetics more than those in the North, where low-maintenance yards were a greater priority.     

Intrinsic and extrinsic drivers of yard vegetation in urban residential areas: implications for conservation planning

Residential green areas often represent a significant portion of a city’s green infrastructure which has generated great interest in studying the factors that contribute to the formation of plant associations in residential yards. This project evaluated the external factors to the household social-ecological system that influence the availability of plants for residential landscapes and how they may influence the presence of native plants in residential yards on households within the Río Piedras watershed in the metropolitan area of San Juan, Puerto Rico. The methods used included a residential survey with open and closed questions that addressed the sources of plants used in landscaping and an evaluation of ornamental plant species inventories from local nurseries. A total of 432 yards were surveyed. Yard plants in this watershed have multiple sources. Aside from obtaining plants at local nurseries, natural dispersion, exchanges among family and friends and historical plantings can be just as important sources of yard plants. Our results also suggest that the majority of residents do not know where to get native plants which could represent a challenge for the development and implementation of initiatives for natives gardening. At the same time, most commercial nurseries have a deficit of native plants in their inventories. This information is critical to species conservation strategies that seek the inclusion of urban residential areas and may help improve initiatives about the involvement of individual citizens in sustainable gardening practices at the residential scale.     

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.     

Small-scale and extensive hydrogeomorphic modification and water redistribution in a desert city and implications for regional nitrogen removal

There are numerous examples of small-scale hydrogeomorphic manipulations within urban ecosystems. These modifications are motivated both by a need to handle storm drainage and by a human desire for aquatic ecosystems as places for recreation and aesthetics. In the Phoenix Arizona metropolitan area, two examples of these local modifications are artificial lakes and stormwater retention basins. Although lakes are not a natural feature of Sonoran Desert ecosystems, numerous artificial lakes are evident in the region. Retention basins are a common landscaping practice for preventing damage from rare but potentially large storm events. Here we attempt to quantify the heretofore unknown number and extent of these designed aquatic ecosystems and consider their potential impact on hydrologic landscape connectivity and regional nitrogen (N) removal. For lakes, we found that official GIS layers from local and state agencies had significant misclassifications and omissions. We used two published GIS datasets and state impoundment-permit information to determine the number, areal extent, and water source for artificial lakes. We discovered that there are 908–1,390 lakes in the Phoenix area, with the number varying according to level of aggregation. There are no existing GIS data on retention basins, so we employed drywell-permit data to estimate that there may be 10,000 retention basins in the region. Basic data on N stocks in these ecosystems are discussed within the context of the regional N budget. Accurate data on the extent and distribution of these designed ecosystems will be vital for water-resources planning and stormwater management.     

Mutualistic relationships versus hyper-efficiencies in the sustainable building and city

The quest for sustainability in the design and development of buildings and cities has expressed itself predominantly as a pursuit of ever-greater efficiency. Urban systems have been developed to achieve energy and resource savings in an attempt to eliminate their environmentally negative impacts. The end goal would seem to be to make buildings and cities virtually invisible within the context of the natural environment and to extract humanity from that which is natural. This approach could be termed as a hyper-efficiency sustainability model. In this approach, the impacts of human beings and their functional systems are seen as contaminants that need reduction or removal. Although driven by a desire to preserve the Earth’s natural systems, such an approach ultimately creates greater division between humanity and nature and may not bring sustainability. As an alternative to a hyper-efficiency model of sustainability, a model should be pursued that focuses more on developing an integrative relationship between civilization and environment akin to mutualism in biology. Such an approach, which could be termed as a mutualistic sustainability model, incorporates natural systems and elements into the structures and functions of buildings and cities, with the goal of achieving cooperative and positive interaction between humanity and nature. Such integration can create opportunities to support living organisms and biological systems in an ecologically contributive manner, while fulfilling human infrastructural needs. It offers a more positive alternative to efficiency based strategies and has the potential to establish a healthier and more productive relationship between humanity and the Earth’s natural systems. This paper elaborates on these two distinct approaches to sustainability and presents an examination of recent green building projects and green infrastructure projects. It analyses specific strategies and methods to contrast and compare manifestations of both approaches, providing valuable lessons and insights for designing sustainable buildings and cities.     

Urbanization drivers differentially affect ground arthropod assemblages in the city of Turin (NW-Italy)

Urban Ecosystems - Urbanization is a complex process associated with environmental changes affecting many biotic and abiotic ecosystem components, which cause the alteration of biological...     

Urban vegetation cover correlates with environmental variables in a desert city: insights of mitigation measures to climate change

Urban Ecosystems - Green cover and air quality are important components of life quality and human ecology in arid lands. In the Sonoran Desert of Mexico, Hermosillo is the largest city with a...     

Lentic and lotic odonate communities and the factors that influence them in urban versus rural landscapes

Habitat alteration via urbanization has very different effects on even closely related taxa. Most research investigating the ecological effects of urbanization has focused on birds or mammals, resulting in a relatively poor understanding of how the species richness and community composition of invertebrates may change. We quantified differences in species richness of adult odonates (dragonflies and damselflies) at lentic and lotic sites in urban and rural landscapes, and we examined environmental factors that might drive the differences in community composition that we observed. For lotic sites, species richness did not differ between urban versus rural sites for either dragonflies or damselflies. For lentic sites, urban and rural sites contained similar dragonfly species richness, but damselfly species richness was significantly lower at urban sites than at rural sites. Differences in lentic odonate community composition were associated with the amount of urban development within 150 m of each site, mean algal coverage, and distance to the urban center. At lotic sites, water temperature and distance to the urban center were correlated with differences in odonate community composition. The differing responses to urbanization observed in this study were probably a consequence of differences between lentic versus lotic ecosystems and between dragonflies versus damselflies in dispersal capability and habitat specificity. Given that different environmental factors affected these taxa differently in lentic and lotic sites, maintaining the highest level of odonate diversity possible across a landscape will require the use of different management practices for each ecosystem type.     

Models of Disability in the Labelling and Attitudinal Discourse in Ghana

This article considers the labelling of people with 'mental retardation' in Ghana against the background of the major underpinning models of disability. The influences of these models on individuals and on services and provisions are discussed. It is argued that traditional and religious beliefs, in addition to present day attitudes within the community, are influences on the perception of 'mental retardation' in Ghana.     

Social, Economic, and Attitudinal Characteristics of Cohabitation in Israel

This article examines cohabitation in Israel. Since the 1980s cohabitation has been on the rise, with heterosexual couples living together without being legally married. The purpose of this article is to address the following questions: What are the characteristics of cohabitation; what economic circumstances affect cohabitation; why is cohabitation chosen over “family” and is it becoming a threat to the family institution? The sample consisted of 50 couples. Our major findings were that cohabitation does not seem to be an alternative to marriage, but a prelude to it. We found a high correlation between the cohabitants' willingness to marry and their willingness to have children in the future. Cohabitants live in rented apartments, usually do not share a bank account, and have no formal economic agreement.     

Flight initiation distance changes across landscapes and habitats in a successful urban coloniser

Urban Ecosystems - Urbanisation is a major land use change that introduces novel sources of disturbance and risk into an ecosystem. Successful urban species modify their fear behaviour in response...     

Predictors of falling in older Maryland drivers: a structural-equation model

Falls can impair health and reduce quality of life among older adults. Although many factors are related to falling, few analyses examine causal models of this behavior. In this study, factors associated with falling were explored simultaneously using structural-equation modeling. A variety of cognitive, physical-performance, and health measures were administered to 694 older adult drivers from the state of Maryland. The observed and latent variables of age, cognitive ability, physical functioning, health, and falling behavior were used to create a causal model. The model revealed that being older was associated with declines in cognition, and such cognitive declines predicted increased falling. Similarly, poorer health was related to poorer physical functioning, which, in turn, also predicted increased falling. This model indicates that in addition to existing fall-prevention interventions aimed at improving physical functioning, interventions to improve cognition and health might also be effective. It is speculated that fear of falling, which often results in reduced mobility among older adults, might account for the lack of a direct relationship between age and falling. This hypothesis should be examined in further research.     

Dialogic landscapes: Toward a nuanced understanding of globalization in urban Indonesian signage

This article shows that a perspective rooted in Bakhtin's dialogism between the fixed centripetal and fluid centrifugal forces of language and culture is useful in achieving a nuanced understanding of globalization in general and semiotic landscapes in Indonesia in particular. Drawing on data from Indonesia, this article shows dialogic interconnections between fixed and fluid notions of languages and cultures through a multimodal and indexical analysis of governmental and commercial signage in the urban center of Semarang, the provincial capital of Central Java. The analysis highlights the nuanced localizing and globalizing strategies in signage and how dialogicity helps shape the semiotic landscape.     

Suburban road-closures and the ruinous landscapes of privilege in Johannesburg

In this article we trace the emergence of road-closures – i.e. the barricading by local residents of public roads ostensibly in response to crime – in the northern suburbs of Johannesburg in the decade after apartheid. We argue that road-closures manifest an attempt at material “fixing” an urban order of privilege, even as privilege and inequality is increasingly “deterritorialised” in the city of the global South. While conventionally theorised as part of a broader global trend towards the privatisation and securitisation of urban space, we demonstrate that road-closures contain qualitatively different expectations of the urban order to e.g. private gated communities. Whereas gated communities are premised on and driven by a political economy of self-exclusion from urban life, road-closures simultaneously resist and prefigure this “deterritorialised” reordering of privilege in the post-apartheid city. Based on archival research in local community newspapers over a 10-year period between and 2004 (the high-water mark of the so-called road-closure “debates”), we trace shifting discourses about road closures and the city: from anxieties about crime and loss of privilege, to fantasies of abandonment, to the assertion (and rupture) of a mythical suburban utopia. Drawing on a literature on ruins as the material effects of a past order manifest in the urban order of the present, we assert that despite anxieties about the loss of privilege, these enclosed neighbourhoods remain spaces of extreme privilege, now implicated into an emergent geography in which old and new spaces of privilege overlap to reinforce spatial inequalities in post-apartheid Johannesburg.     

Neoliberal disorientations: changing landscapes of disability and governance in India

This article delves into questions of neoliberal disorientations experienced by disabled people in the context of a participatory development self-help group project from the World Bank in south India. I explore ways in which neoliberal development regimes produce exclusionary forms of inclusion by producing subjects who are ‘able-disabled’. I ethnographically examine ‘who gets counted’ and ‘what gets counted’ within the neoliberal governance framework, and what remains outside. Deconstructing participatory development approaches from a critical disability perspective, the article sheds light on processes of inclusion through exclusion in the neoliberal framework of governance. It highlights what is at stake for disability futures in the context of austerity in the Global South.     

Maternal situations: sectarianism and civility in a divided city

This paper explores the tensions between civility and sectarianism in contemporary Belfast. Drawing on interviews with mothers engaged in raising young children in the largely working‐class and divided inner city, the paper offers a situated account of the dynamics of social reproduction and change. This is pursued through an analysis of the interplay between expectations of civility and sectarianism in three situations: walking, shopping and playing. The tensions and dilemmas of maternal action as the divided inner city is navigated indicate the gendered character of civility, an important emerging norm facilitating social change in the post‐conflict era. The situation of motherhood itself, both at the centre of ethno‐national reproduction and at the interface of public and private life, is not insignificant in routinely drawing mothers into the everyday dynamics of post‐conflict continuity and change.     

A city within a city: A “snapshot” of aging in a HUD 202 in Detroit, Michigan

Because of a recent surge of aging in place literature, we know a considerable amount about how older adults wish to remain in long lived-in homes and communities. However, there are still gaps in our knowledge. What happens when older adults live in a community that does not support their everyday needs? This paper represents an initial attempt to explore how one group of poor, non-white, central city residents in Detroit, Michigan make sense of and organize a new age-segregated home. Findings presented in this article are based on 30 in depth and photographic elicitation interviews with African American, low-income, older adults living in one Housing and Urban Development 202 (HUD 202). Findings suggest that participants in this sample cultivated a new urban space within the facility to compensate for the deficiencies of a deteriorated inner-city neighborhood. I use these findings to encourage broader conceptualizations and consideration for the aging in place model to be more inclusive to the lived experiences of older adults who occupy oppressed places.     

中国城市居住区更新——问题综述与未来策略

一、当前城市居住区更新存在的问题 (一)大规模推倒重建 从全国来看,一些城市居住区更新改造不是通过保留、维修、整治和重建等多种方式进行,而是一律采用“推倒重建”的方式,同时不注意选择合适的时机,不能适当地掌握节奏和速度,造成改造规模过大、速度过快。 国内学术界对大规模改造的反思,出现于80年代中后期,90年代以后,大规模改造则受到更为广泛的质疑。