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151.
152.
A new method for analysing socio-ecological patterns of vulnerability   总被引:1,自引:0,他引:1  
This paper presents a method for the analysis of socio-ecological patterns of vulnerability of people being at risk of losing their livelihoods as a consequence of global environmental change. This method fills a gap in methodologies for vulnerability analysis by providing generalizations of the factors that shape vulnerability in specific socio-ecological systems and showing their spatial occurrence. The proposed method consists of four steps that include both quantitative and qualitative analyses. To start, the socio-ecological system exposed to global environmental changes that will be studied needs to be determined. This could, for example, be farmers in drylands, urban populations in coastal areas and forest-dependent people in the tropics. Next, the core dimensions that shape vulnerability in the socio-ecological system of interest need to be defined. Subsequently, a set of spatially explicit indicators that reflect these core dimensions is selected. Cluster analysis is used for grouping the indicator data. The clusters found, referred to as vulnerability profiles, describe different typical groupings of conditions and processes that create vulnerability in the socio-ecological system under study, and their spatial distribution is provided. Interpretation and verification of these profiles is the last step in the analysis. We illustrate the application of this method by analysing the patterns of vulnerability of (smallholder) farmers in drylands. We identify eight distinct vulnerability profiles in drylands that together provide a global overview of different processes taking place and sub-national detail of their distribution. By overlaying the spatial distribution of these profiles with specific outcome indicators such as conflict occurrence or migration, the method can also be used to understand these phenomena better. Analysis of vulnerability profiles will in a next step be used as a basis for identifying responses to reduce vulnerability, for example, to facilitate the transfer of best practices to reduce vulnerability between different places.  相似文献   
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154.
This study performed the first systematic evaluation of the success of habitat mitigation at establishing the threatened Valley elderberry longhorn beetle (Desmocerus californicus dimorphus) and its host plant, blue elderberry (Sambucus mexicana). Habitat mitigation performed through enforcement of the U.S. Endangered Species Act represents a tightly controlled form of habitat restoration, facilitating the evaluation of restoration practice. Restoration plantings of blue elderberry have been substantial in our study area, the Central Valley of California. Surveys of 30 mitigation sites and 16 nearby natural sites showed that mitigation sites were a fraction of the size of natural habitat areas (mean = 24%) and contained smaller shrubs. The beetle colonized 53% of mitigation sites and its populations were denser in sites with moderate levels of dead stems on elderberry shrubs, and moderate damage to elderberry stems and bark. This likely indicates that the beetle responds to stressed shrubs, which are likely to contain elevated levels of nitrogen. Beetle density also increased with the size and age of mitigation sites. This indicates a need to make restoration sites as large as possible and to monitor these sites for longer than current guidelines suggest, thereby allowing more time for convergence of natural and mitigation sites. Few factors examined here directly influenced the growth of elderberry shrubs, but elderberry grew more rapidly in sites closer to riparian areas, indicating that such sites should be favored for mitigation sites.  相似文献   
155.
In an experimental set-up, a colony of the stingless bee Melipona fasciata demonstrated its ability to choose the better of two nectar sources. This colony pattern was a result of the following individual behavioural decisions: continue foraging, abandon the feeder, restart foraging and initiate foraging. Only very rarely did individuals switch from one feeder to the other. With the first combination of a rich (2.7 M) and a poor (0.8 M) feeder M. fasciata behaved differently from Apis mellifera. Recruitment occurred to both feeders and the poor feeder was not abandoned completely. When the poor feeder was set to 0.4 M, M. fasciata abandoned the poor feeder rapidly and allocated more foragers to the rich feeder. These patterns were similar to those reported for A. mellifera with the first combination of feeders. Over a sequence of 4 days, experienced bees increasingly determined the colony patterns, and the major function of communication between workers became the reactivation of experienced foragers. The foragers modulated their behaviour not only according to the profitability of the feeder, but also according to previous experience with profitability switches. Thus, experience and communication together regulated colony foraging behaviour. These findings and the results of studies with honeybees suggest that M. fasciata and honeybees use similar decision-making mechanisms and only partly different tools. Received: 21 December 1998 / Accepted: 5 January 1999  相似文献   
156.
We combined a natural experiment with field surveys and GIS to investigate the effects of dust from recreational trails and access roads on the federally threatened Valley elderberry longhorn beetle (“VELB,” Desmocerus californicus dimorphus) and its host plant, elderberry (Sambucus mexicana). Dust is listed in the species recovery plan as a threat to the VELB and unpaved surfaces are common throughout the riparian corridors where the VELB lives, yet the effects of dust on the VELB have been untested. We found that dust deposition varied among sites and was highest within 10 m of trails and roads, but was similar adjacent to dirt and paved surfaces within sites. Elderberry density did not differ with distance from dirt surfaces. Despite similar within-site dust levels, elderberry adjacent to paved surfaces were less stressed than those near dirt ones, possibly because increased runoff from paved surfaces benefited elderberry. Dust deposition across sites was weakly correlated with elderberry stress symptoms (e.g., water stress, dead stems, smaller leaves), indicating that ambient dust (or unmeasured correlates) influenced elderberry. Direct studies of the VELB showed that its distribution was not negatively affected by the proximity to dirt surfaces. Dust from low traffic dirt and paved access roads and trails, therefore, affected VELB presence neither directly nor indirectly through changed elderberry condition. These results suggest that the placement of VELB mitigation, restoration, and conservation areas can proceed independently of access roads if dust and traffic levels do not exceed those in our study site. Furthermore, dust control measures are likely to be unnecessary under such conditions. The potential effects of increased traffic and dust levels are addressed through a literature review.  相似文献   
157.
Recycling of construction and demolition waste contributes decisively to the saving of natural mineral resources. In Germany, processed mineral construction and demolition waste from structural engineering is used nearly exclusively in civil engineering (earthwork and road construction sector) as open-loop recycling. Due to the planned stricter limit values for the protection of soil and water, however, this recycling path in civil engineering may no longer be applicable in the future. According to some new guidelines and standards adopted recently, recycled aggregates may also be used for concrete production in the structural engineering sector (closed-loop recycling). Wastes from the structural engineering sector can thus be kept in a closed cycle, and their disposal on a landfill can be avoided. The present report focuses on the determination of maximum waste volumes that may be handled by this new recycling option. Potential adverse effects on the saving of resources and climate protection have been analysed. For this purpose, materials flow analysis and ecobalancing methods have been used.  相似文献   
158.
Thanks to developments in genomics,dietary recommendations adapted to genetic riskprofiles of individual persons are no longerscience fiction. But what are the consequencesof these diets? An examination of possibleimpacts of genetically tailor-made diets raisesmorally relevant concerns that are analogous to(medical-ethical) considerations aboutscreening and testing. These concerns oftengive rise to applying norms for informedconsent and for the weighing of burdens andbenefits. These diets also have a broaderimpact, especially because food patterns arefull of personal, social and cultural meanings.Diets will change one's food patterns and one'sattitude towards food, and this may implychanges in one's identity. We argue that suchan impact does not necessarily raise moralproblems. Moral concerns are, however, relevantif collective values and shared meanings infood practices are at issue. Therefore, thedevelopment of genetically tailor-made dietsdoes not merely require emphasis on weighingpersonal benefits and burdens and on informedconsent. It also asks for attention to andmoral reflection on the collective valuesinvolved in food practices.  相似文献   
159.
ABSTRACT

In the climate and land use fields, policy mixes are complex in terms of the levels of governance, actors, and roles. They consist of policy instruments that target different actors and address multiple goals across several policy sectors and levels. The analysis of these complex arrangements extends beyond purely technical efficiency criteria, as several sources of tension between instruments may be identified, such as conflicting interests, goals, and approaches to implementation. The proliferation of governance networks complicates the understanding of actors’ interactions, the types of authority influencing the outcomes of policy mixes, and importance of different levels of governance. This article provides a framework to address these analytical challenges, particularly the interconnected networks of policy actors and policy instruments. It draws on polycentric governance literature to analyse how power matters in policy networks. This includes identifying distinct types of power, actors’ position, and variables that explain patterns of conflict, competition, convergence, and divergence in policy choices and outcomes. The framework is applied to the climate and land use policies implemented in the state of Mato Grosso, Brazil. Several methods were used to clarify these variables and to characterise policy mixes being implemented in the region, including social network analysis.  相似文献   
160.
Environmental Geochemistry and Health - Khat (Catha edulis) chewing is widespread in the region of East Africa. Even low levels of organochlorine pesticides (OCPs) in khat could induce public...  相似文献   
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