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241.
John E. Fa Jesus Olivero Miguel Á. Farfán Ana L. Márquez Jesús Duarte Janet Nackoney Amy Hall Jef Dupain Sarah Seymour Paul J. Johnson David W. Macdonald Raimundo Real Juan M. Vargas 《Conservation biology》2015,29(3):805-815
We used data on number of carcasses of wildlife species sold in 79 bushmeat markets in a region of Nigeria and Cameroon to assess whether species composition of a market could be explained by anthropogenic pressures and environmental variables around each market. More than 45 mammal species from 9 orders were traded across all markets; mostly ungulates and rodents. For each market, we determined median body mass, species diversity (game diversity), and taxa that were principal contributors to the total number of carcasses for sale (game dominance). Human population density in surrounding areas was significantly and negatively related to the percentage ungulates and primates sold in markets and significantly and positively related to the proportion of rodents. The proportion of carnivores sold was higher in markets with high human population densities. Proportion of small‐bodied mammals (<1 kg) sold in markets increased as human population density increased, but proportion of large‐bodied mammals (>10 kg) decreased as human population density increased. We calculated an index of game depletion (GDI) for each market from the sum of the total number of carcasses traded per annum and species, weighted by the intrinsic rate of natural increase (rmax) of each species, divided by individuals traded in a market. The GDI of a market increased as the proportion of fast‐reproducing species (highest rmax) increased and as the representation of species with lowest rmax (slow‐reproducing) decreased. The best explanatory factor for a market's GDI was anthropogenic pressure—road density, human settlements with >3000 inhabitants, and nonforest vegetation. High and low GDI were significantly differentiated by human density and human settlements with >3000 inhabitants. Our results provided empirical evidence that human activity is correlated with more depleted bushmeat faunas and can be used as a proxy to determine areas in need of conservation action. 相似文献
242.
Policy windows are transitory opportunities during which the likelihood of adopting new policy or legislative proposals is
greater than usual. Accepted wisdom has held that natural disasters serve as focusing events that generate policy windows
in their wake. This paper highlights the need for a more circumscribed understanding of when and where policy windows occur
based on the experiences of three US regional planning organizations: a hand-picked commission of community leaders, a council
of governments, and a special-purpose substate organization. The first operated in the San Francisco Bay Area of California
following the Loma Prieta earthquake (October 1989), and the other two in South Carolina's Atlantic coastal plain after Hurricane
Hugo (September 1989). The analysis concludes that natural disasters did not transform the agenda or mission of these entities.
Policy windows were neither automatic outcomes of focusing events nor did they ensure the adoption of pertinent policy within
the organizations investigated. Several conditions are minimally necessary for using policy windows to bring about hazard
mitigation: comprehensive institutional conceptualization of hazards management, institutional strength and flexibility, and
well-placed, effective policy entrepreneurs. 相似文献
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246.
Dr Mitchell S. Golbus Joe Leigh Simpson Sarah E. Fowler Felix de la Cruz Robert J. Desnick Ronald Wapner David H. Ledbetter Herbert Lubs Maurice J. Mahoney Eugene Pergament George G. Rhoads Joseph D. Schulman Julia Zachary 《黑龙江环境通报》1992,12(5):373-376
Factors found to be associated with pregnancy loss after transcervical CVS were race (higher for non-white), history of spontaneous abortion, unplanned pregnancy, history of spotting or bleeding during the pregnancy prior to CVS, and placental position (higher for fundal or lateral locations). Whether the increase in loss risk is due to the factor, per se, or the factor plus the CVS cannot be determined due to the lack of appropriate control data. 相似文献
247.
248.
de Aragão Umbuzeiro G Freeman HS Warren SH de Oliveira DP Terao Y Watanabe T Claxton LD 《Chemosphere》2005,60(1):55-64
To verify whether dyes emitted within the discharge of a dye processing plant were contributing to the mutagenicity repeatedly found in the Cristais River, Sao Paulo, Brazil, we chemically characterized the following mutagenic samples: the treated industrial effluent, raw and treated water, and the sludge produced by a Drinking Water Treatment Plant (DWTP) located approximately 6 km from the industrial discharge. Considering that 20% of the dyes used for coloring activities might be lost to wastewaters and knowing that several dyes have mutagenic activity, we decided to analyze the samples for the presence of dyes. Thin layer chromatographic analysis indicated the presence of three prevalent dyes in all samples, except for the drinking water. This combination of dyes corresponded to a commercial product used by the industry, and it tested positive in the Salmonella assay. The structures of the dye components were determined using proton magnetic resonance and mass spectrometric (MS) methods, and the dyes were tested for mutagenicity. The blue component was identified as the C.I. Disperse Blue 373, the violet as C.I. Disperse Violet 93, and the orange as C.I. Disperse Orange 37. The dyes showed mutagenic responses of 6300, 4600, and 280 revertants/microg for YG1041 with S9 respectively. A bioassay-directed fractionation/chemical analysis showed that the C.I. Disperse Blue 373 contributed 55% of the mutagenic activity of the DWTP sludge. We showed that these dyes contributed to the mutagenic activity found in the Cristais River environmental samples analyzed and are indirectly affecting the quality of the related drinking water. Therefore, we believe that this type of discharge should be more thoroughly characterized chemically and toxicologically. Additionally, human and ecological risks associated with the release of dye processing plant effluents should be more fully investigated, especially where the resultant water is taken for human consumption. 相似文献
249.
Habitat Loss and Extinction in the Hotspots of Biodiversity 总被引:34,自引:0,他引:34
250.
Soil responses to management, increased precipitation, and added nitrogen in ponderosa pine forests. 总被引:1,自引:0,他引:1
Bruce A Hungate Stephen C Hart Paul C Selmants Sarah I Boyle Catherine A Gehring 《Ecological applications》2007,17(5):1352-1365
Forest management, climatic change, and atmospheric N deposition can affect soil biogeochemistry, but their combined effects are not well understood. We examined the effects of water and N amendments and forest thinning and burning on soil N pools and fluxes in ponderosa pine forests near Flagstaff, Arizona (USA). Using a 15N-depleted fertilizer, we also documented the distribution of added N into soil N pools. Because thinning and burning can increase soil water content and N availability, we hypothesized that these changes would alleviate water and N limitation of soil processes, causing smaller responses to added N and water in the restored stand. We found little support for this hypothesis. Responses of fine root biomass, potential net N mineralization, and the soil microbial N to water and N amendments were mostly unaffected by stand management. Most of the soil processes we examined were limited by N and water, and the increased N and soil water availability caused by forest restoration was insufficient to alleviate these limitations. For example, N addition caused a larger increase in potential net nitrification in the restored stand, and at a given level of soil N availability, N addition had a larger effect on soil microbial N in the restored stand. Possibly, forest restoration increased the availability of some other limiting resource, amplifying responses to added N and water. Tracer N recoveries in roots and in the forest floor were lower in the restored stand. Natural abundance delta15N of labile soil N pools were higher in the restored stand, consistent with a more open N cycle. We conclude that thinning and burning open up the N cycle, at least in the short-term, and that these changes are amplified by enhanced precipitation and N additions. Our results suggest that thinning and burning in ponderosa pine forests will not increase their resistance to changes in soil N dynamics resulting from increased atmospheric N deposition or increased precipitation due to climatic change. Restoration plans should consider the potential impact on long-term forest productivity of greater N losses from a more open N cycle, especially during the period immediately after thinning and burning. 相似文献