Elevated phosphorus: dynamics during four years of green roof development

Green roofs are emerging engineered ecosystems that provide multiple benefits, but many are constructed with nutrient-rich substrate and have been found to leach out high levels of phosphorus (P) in runoff. It is unclear, however, how long green roofs act as sources of P or what mechanisms are responsible for these net losses. We measured P concentrations in runoff water over 4 years from a 1–5 year old extensive green roof in Cincinnati, OH, USA, produced a model to predict runoff P levels into the future, and validated predictions using runoff from 2 nearby extensive green roofs. P concentrations in runoff from the focal green roof were on par with heavily fertilized agroecosystems and displayed strong seasonal dynamics and a rapid decline over the 4-year study. Runoff measurements and changes in substrate P content over a 2-year period were used to estimate a mass balance for green roof P. P loss from the substrate was substantial (4.55 ± 2.3 g P/m²/yr), but only a small portion of the loss was attributable to leaching of P in runoff (0.19–0.65 g P/m²/yr). Missing P may be attributed to a combination of plant uptake and altered P form and binding strength, but further research is needed to precisely identify the mechanisms of P depletion. Our results also suggest that these and similar extensive green roofs are likely to act as environmentally significant sources of P for 10 or more years following roof installation, highlighting the need for reductions in initial substrate P content.     

The Persistence of Neighboring as a Determinant of Community Attachment: A Community Field Perspective*

We examined the community field perspective as a complement to the linear‐development and systemic models of community attachment, wherein community attachment is defined as a social bond to the community of place. We empirically evaluated indicators of the actor's interaction within the social field, such as the perceived quality of neighboring and density of friendships, using social survey and census data from 99 communities in 1994 and 2004 and evaluated as well the percentage change in these indicators from 1994 to 2004. Results show that the community field perspective can complement previous approaches by highlighting the importance of perceived neighboring and friendship density and the persistence of perceived neighboring over time. We suggest implications for community development efforts aimed at enhancing community attachment.     

Quantifying the Hurricane Catastrophe Risk to Offshore Wind Power

The U.S. Department of Energy has estimated that over 50 GW of offshore wind power will be required for the United States to generate 20% of its electricity from wind. Developers are actively planning offshore wind farms along the U.S. Atlantic and Gulf coasts and several leases have been signed for offshore sites. These planned projects are in areas that are sometimes struck by hurricanes. We present a method to estimate the catastrophe risk to offshore wind power using simulated hurricanes. Using this method, we estimate the fraction of offshore wind power simultaneously offline and the cumulative damage in a region. In Texas, the most vulnerable region we studied, 10% of offshore wind power could be offline simultaneously because of hurricane damage with a 100‐year return period and 6% could be destroyed in any 10‐year period. We also estimate the risks to single wind farms in four representative locations; we find the risks are significant but lower than those estimated in previously published results. Much of the hurricane risk to offshore wind turbines can be mitigated by designing turbines for higher maximum wind speeds, ensuring that turbine nacelles can turn quickly to track the wind direction even when grid power is lost, and building in areas with lower risk.     

Transition from school for youths with a disability: issues and challenges

Australian research has demonstrated that students with a disability are more likely to remain out of the full‐time workforce. These research findings have been the catalyst for a call for a comprehensive career development and transition planning approach for all students with disabilities in schools as well as for employers to rethink the role of people with disabilities in the workforce. In the Australian context the transition from school for individuals with a disability is complicated by a disparate and fragmented group of service agencies providing a range of services, including employment, supported accommodation, recreation and leisure pursuits, as well as training and placement, along with, at times, a deep‐seated prejudice towards people with disabilities in the market place. This paper reviews a number of issues and challenges confronting individuals with a disability making the transition from school to the post‐school environment.     

Into the divide: community identities and the visualisation of place

This article discusses the experience of place in a profoundly divided urban area of Sheffield. At a time when the gap between affluence and poverty has reached its widest point since the 1960s, this article explores the relationship between individuals and their sense of place and of the trenchant divisions separating communities. The study employs various methods but centres upon the use of hand-drawn maps; creating a dialogue between the interviewers and a number of local residents. These maps and the accompanying commentaries demonstrate the diverse individual sense of a particular place and a dialectical sense of space. The resulting picture is one of both the persistence of historical divisions, suggesting regulation and control through planning and policing, but also of complex entanglements of social identities, habitus and place which defy easy categorisation.     

Rational exchange and trust: Business relationships in a fishing community

This paper assesses the hypothesis that in markets where information is lacking concerning the price and the quality of a commodity and the commodity is variable in its supply, sellers will tend to form long‐term, stable relationships with buyers. Data from a coastal Alabama community are used to test the nature of exchange relations between commercial shrimp fishers and the dealers to whom they sell. It is further hypothesized that the social aspects of these exchanges will better predict stable relationships than will economic aspects. The evidence presented supports the stated hypotheses. Finally, the relevance of this research for social theory is discussed.