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311.
Mann S 《Journal of environmental management》2007,85(1):198-203
Major benefit uncertainties prevent monetary quantification of some environmental amenities. Replacing mineral lubricants with biodegradable substitutes is shown to be a case in point. However, it is possible to rank the social benefits of substituting mineral lubricants with regard to different applications and environments. As the private costs and benefits of substitution are mainly constant, only a policy that prioritizes full substitution in the applications with the greatest benefits can be efficient. It is shown that regulations requiring substitution in certain fields are likely to fulfil this criterion, while subsidies for production, processing, market introduction and research usually fail to meet the efficiency criterion. 相似文献
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Stefan Greiving Mark Fleischhauer Johannes Lückenkötter 《Journal of Environmental Planning and Management》2006,49(1):1-19
Natural and technological disasters of the past have shown that such incidences significantly affect local and regional development. Faced with the task of ensuring economic, human and environmental development as well as insuring physical structures, planning authorities, insurance companies and emergency managers are looking for methodologies to identify highly sensitive areas in terms of their overall risk. Existing methodologies like the Natural Hazard Index for Megacities or the Total Place Vulnerability Index have limitations due to their sectoral approach, which makes them less useful for integrated spatial planning. This paper presents the Integrated Risk Assessment of Multi-Hazards as a new approach to serve as a basis for a spatial risk management process. The approach integrates various hazards into an integrated hazard map, combines this with the region's vulnerability and thus produces an integrated risk map. Moreover, the methodology offers a tool to derive weighting factors for hazards as well as for vulnerability components. 相似文献
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Ohne Zusammenfassung
Dipl.-Chem. Dr. Stefan Nowicki ist Physiko-Chemiker mit Spezialgebiet in der Phasen- und Grenzfl?chenchemie. Als Prokurist
und Leiter Forschung und Entwicklung der S?ll GmbH in Hof/Oberfranken geh?rt zu seinem Aufgabengebiet die chemikalienrechtliche
überwachung und Ausstattung der Produkte und die Einhaltung der o.a. Richtlinien beim Tochterunternehmen Lavaris-Lake GmbH. 相似文献
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319.
Schnitzer SA Klironomos JN Hillerislambers J Kinkel LL Reich PB Xiao K Rillig MC Sikes BA Callaway RM Mangan SA van Nes EH Scheffer M 《Ecology》2011,92(2):296-303
Ecosystem productivity commonly increases asymptotically with plant species diversity, and determining the mechanisms responsible for this well-known pattern is essential to predict potential changes in ecosystem productivity with ongoing species loss. Previous studies attributed the asymptotic diversity-productivity pattern to plant competition and differential resource use (e.g., niche complementarity). Using an analytical model and a series of experiments, we demonstrate theoretically and empirically that host-specific soil microbes can be major determinants of the diversity-productivity relationship in grasslands. In the presence of soil microbes, plant disease decreased with increasing diversity, and productivity increased nearly 500%, primarily because of the strong effect of density-dependent disease on productivity at low diversity. Correspondingly, disease was higher in plants grown in conspecific-trained soils than heterospecific-trained soils (demonstrating host-specificity), and productivity increased and host-specific disease decreased with increasing community diversity, suggesting that disease was the primary cause of reduced productivity in species-poor treatments. In sterilized, microbe-free soils, the increase in productivity with increasing plant species number was markedly lower than the increase measured in the presence of soil microbes, suggesting that niche complementarity was a weaker determinant of the diversity-productivity relationship. Our results demonstrate that soil microbes play an integral role as determinants of the diversity-productivity relationship. 相似文献
320.
Cyclic population dynamics of forest insects with periods of more than two generations have been discussed in relation to a variety of extrinsic and intrinsic forces. In the present study, we employed the selection pressure of density dependent competitive interactions according to Witting's equations (Witting, 2000) as driver for a discrete spatiotemporal model of the green oak leaf roller (Tortrix viridana). The model was successfully parameterised to rebuild the cyclic population dynamics of an empirical data set of a 30-year leaf roller monitoring in Russia. Our analysis focussed on the role of herbivore mortality and host plant food quality, which have a significant effect on T. viridana population dynamics. An additional egg or larvae mortality lowers population density and can lead to selection pressures that favour individuals with higher growth rate. This increased population growth rate can not only compensate the additional mortality, but also can lead to higher average moth abundances in subsequent generations. Furthermore, we analysed the effect of inter- and intraspecific variation in host plant quality on herbivore population dynamics and the spatial distribution of abundance and defoliation patterns. We found significant effects of the qualitative composition of a trees neighbourhood on the herbivore population of the respective tree. Also, the patchy damage patterns observable in reality have been reproduced by the present model. The applicability of the model approach and the putative genetic processes underlying Witting's model are discussed. 相似文献