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Mapping the economic costs and benefits of conservation   总被引:13,自引:1,他引:13       下载免费PDF全文
Resources for biodiversity conservation are severely limited, requiring strategic investment. Understanding both the economic benefits and costs of conserving ecosystems will help to allocate scarce dollars most efficiently. However, although cost-benefit analyses are common in many areas of policy, they are not typically used in conservation planning. We conducted a spatial evaluation of the costs and benefits of conservation for a landscape in the Atlantic forests of Paraguay. We considered five ecosystem services (i.e., sustainable bushmeat harvest, sustainable timber harvest, bioprospecting for pharmaceutical products, existence value, and carbon storage in aboveground biomass) and compared them to estimates of the opportunity costs of conservation. We found a high degree of spatial variability in both costs and benefits over this relatively small (~3,000 km2) landscape. Benefits exceeded costs in some areas, with carbon storage dominating the ecosystem service values and swamping opportunity costs. Other benefits associated with conservation were more modest and exceeded costs only in protected areas and indigenous reserves. We used this cost-benefit information to show that one potential corridor between two large forest patches had net benefits that were three times greater than two otherwise similar alternatives. Spatial cost-benefit analysis can powerfully inform conservation planning, even though the availability of relevant data may be limited, as was the case in our study area. It can help us understand the synergies between biodiversity conservation and economic development when the two are indeed aligned and to clearly understand the trade-offs when they are not.  相似文献   
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Waterlogging responses of an emergent freshwater macrophyte, Schoenoplectus scirpoides, were investigated by carrying out laboratory and field experiments. Soil cores containing uniform plants of S. scirpoides were subjected to drained, 1/3 flooded, alternately flooded and drained at weekly intervals, and continuously flooded treatments for 6 months. Mean soil redox potential of the drained soil was 225 ± 29 mV and was significantly lower in the other treatments. Total dry biomass, above‐ground biomass and number of culms in the flooded/drained and flooded treatments were significantly higher than those in the drained and 1/3 flooded treatments. Below‐ground/above‐ground biomass ratios were highest in the drained treatment and significantly lower in the waterlogged treatments. Plant height and the growth rate of culms were least in the drained treatment and significantly higher in the other treatments. Culm specific gravity decreased significantly with increase in soil moisture. In the field study, soil redox potentials were moderately reduced in the inland and streamside sites, while culm elongation rate was significantly higher by 94% in the streamside compared with the inland site. Optimum growth occurred under flooded conditions, suggesting that the species could flourish with increasing water intrusion in estuarine areas, as predicted by global climate change.  相似文献   
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Human alpha 1-antichymotrypsin has been cloned, sequenced and expressed in Escherichia coli and recombinant protein as well as point-specific mutants have been purified and characterized. The corrected gene-deduced amino acid sequence has 45% overall identity with alpha 1-protease inhibitor, which is higher than the 42% previously reported (Chandra, T., Stackhouse, R., Kidd, V. J., Robson, J. H., and Woo, S. L. C. (1983) Biochemistry 22, 5055-5060). Recombinant antichymotrypsin (rACT) is similar to natural antichymotrypsin with respect to the specificity of its interactions with proteases. Its second-order rate constant for association with bovine chymotrypsin is 6-8 x 10(5) M-1 s-1, which is identical to that of the serum-derived inhibitor. Site-specific mutagenesis has been used to produce two variants of rACT in which the P1 position has been changed from leucine to either methionine (L358M-rACT) or arginine (L358R-rACT). L358M-rACT has a specificity of inhibitory activity toward serine proteases closely similar to that of native rACT. By contrast, the specificity of L358R-rACT is quite different from that of native rACT, most notably in efficiently inhibiting trypsin and human thrombin while showing a decreased ability to inhibit chymotrypsin.  相似文献   
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Biodiversity conservation, as an environmental goal, is increasingly recognized to be connected to the socioeconomic well-being of local communities. The development of a widespread community-based natural resource management (CBNRM) program in Namibia makes it an ideal location to analyze the connection between conservation and socioeconomic well-being of local communities. Namibia’s CBNRM program involves the formation of communal conservancies within rural communities and previous studies have found it to be successful on both ecological and economic fronts. In order to broaden the understanding of the program’s impact to include social factors, we have conducted a comparative analysis to determine the effects of this program on household welfare outcomes. Data from two rounds of the Namibia Demographic and Health Surveys (2000 and 2006/07) and quasi-experimental statistical methods were used to evaluate changes in various health, education and wealth outcomes of those living in conservancies, relative to non-conservancy comparison groups. Regression results indicate mixed effects of the conservancy program at the household level. The program had positive effects on some health outcome variables, including bednet ownership, which was twice as likely to increase over time in conservancy compared to non-conservancy households. Program impacts were negative for education outcomes, with the proportion of school attendance of conservancy children being 45% less likely to increase over time than non-conservancy children. Wealth outcome results were inconclusive. Our findings highlight the importance of analyzing community conservation programs at a variety of scales when evaluating overall impact, as community-level benefits may not necessarily extend down to the household level (and vice versa).  相似文献   
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Reducing gender inequality is a major policy concern worldwide, and one of the Sustainable Development Goals. However, our understanding of the magnitude and spatial distribution of gender inequality results either from limited-scale case studies or from national-level statistics. Here, we produce the first high resolution map of gender inequality by analyzing over 689,000 households in 47 countries. Across these countries, we find that male-headed households have, on average, 13% more asset wealth and 303% more land for agriculture than do female-headed households. However, this aggregate global result masks a high degree of spatial heterogeneity, with bands of both high inequality and high equality apparent in countries and regions of the world. Further, areas where inequality is highest when measured by land ownership generally are not the same areas that have high inequality as measured by asset wealth. Our metrics of gender inequality in land and wealth are not strongly correlated with existing metrics of poverty, development, and income inequality, and therefore provide new information to increase the understanding of one critical dimension of poverty across the globe.  相似文献   
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Introduction

Low and middle income countries bear the majority burden of self-harm, yet there is a paucity of evidence detailing risk-factors for self-harm in these populations. This study aims to identify environmental, socio-economic and demographic household-level risk factors for self-harm in five impoverished urban communities in Johannesburg, South Africa.

Methods

Annual serial cross-sectional surveys were undertaken in five impoverished urban communities in Johannesburg for the Health, Environment and Development (HEAD) study. Logistic regression analysis using the HEAD study data (2006–2011) was conducted to identify household-level risk factors associated with self-harm (defined as a self-reported case of a fatal or non-fatal suicide attempt) within the household during the preceding year. Stepwise multivariate logistic regression analysis was employed to identify factors associated with self-harm.

Results

A total of 2 795 household interviews were conducted from 2006 to 2011. There was no significant trend in self-harm over time. Results from the final model showed that self-harm was significantly associated with households exposed to a violent crime during the past year (Adjusted Odds Ratio (AOR) 5.72; 95% CI 1.64–19.97); that have a member suffering from a chronic medical condition (AOR 8.95; 95% 2.39–33.56) and households exposed to indoor smoking (AOR 4.39; CI 95% 1.14–16.47).

Conclusion

This study provides evidence on household risk factors of self-harm in settings of urban poverty and has highlighted the potential for a more cost-effective approach to identifying those at risk of self-harm based on household level factors.  相似文献   
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