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Abstract: Terrestrial salamanders of the family Plethodontidae have unique attributes that make them excellent indicators of biodiversity and ecosystem integrity in forested habitats. Their longevity, small territory size, site fidelity, sensitivity to natural and anthropogenic perturbations, tendency to occur in high densities, and low sampling costs mean that counts of plethodontid salamanders provide numerous advantages over counts of other North American forest organisms for indicating environmental change. Furthermore, they are tightly linked physiologically to microclimatic and successional processes that influence the distribution and abundance of numerous other hydrophilic but difficult-to-study forest-dwelling plants and animals. Ecosystem processes such as moisture cycling, food-web dynamics, and succession, with their related structural and microclimatic variability, all affect forest biodiversity and have been shown to affect salamander populations as well. We determined the variability associated with sampling for plethodontid salamanders by estimating the coefficient of variation (CV ) from available time-series data. The median coefficient of variation indicated that variation in counts of individuals among studies was much lower in plethodontids (27%) than in lepidoptera (93%), passerine birds (57%), small mammals (69%), or other amphibians (37–46%), which means plethodontid salamanders provide an important statistical advantage over other species for monitoring long-term forest health.  相似文献   

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应用鱼类生物完整性指数评价荔浦河河流健康   总被引:2,自引:0,他引:2  
生物完整性指数是河流生态系统健康评价主要方法之一。为评价荔浦河河流健康状况,选择鱼类作为指示生物,构建了基于鱼类生物完整性指标体系。2017年1月、4月、7月和10月对荔浦河4次采样共采集到鱼类21 192尾,经鉴定共计94种,隶属于6目17科62属。以S1(修仁镇)、S10(马岭镇)、S11(双江镇)作为参考点,经过分布范围分析、箱体图判别能力分析及相关性分析等指标筛选过程从25个候选指标筛选出5个指标,即鱼类总物种数、Shannon-Wiener多样性指数、肉食性鱼类数量百分比、敏感性鱼类数量百分比、产漂浮型卵鱼类数量百分比。将荔浦河河流健康等级分为"健康"、"一般"、"较差"、"极差"和"无鱼"5个等级。结果表明,荔浦河青山镇、荔浦县及蒲芦乡河段健康状态为"一般"水平,东昌镇、龙怀乡、杜莫镇及新坪镇河段健康状态为"较差"水平,茶城乡河段健康状态为"极差"水平。筑坝工程、架桥工程和修路工程等人类活动导致荔浦河支流上的健康状况比干流更差。上述研究结果可为荔浦河的河流管理和保护提供理论依据和技术支持。  相似文献   

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Abstract: Studies have documented biodiversity losses due to intensification of coffee management (reduction in canopy richness and complexity). Nevertheless, questions remain regarding relative sensitivity of different taxa, habitat specialists, and functional groups, and whether implications for biodiversity conservation vary across regions. We quantitatively reviewed data from ant, bird, and tree biodiversity studies in coffee agroecosystems to address the following questions: Does species richness decline with intensification or with individual vegetation characteristics? Are there significant losses of species richness in coffee‐management systems compared with forests? Is species loss greater for forest species or for particular functional groups? and Are ants or birds more strongly affected by intensification? Across studies, ant and bird richness declined with management intensification and with changes in vegetation. Species richness of all ants and birds and of forest ant and bird species was lower in most coffee agroecosystems than in forests, but rustic coffee (grown under native forest canopies) had equal or greater ant and bird richness than nearby forests. Sun coffee (grown without canopy trees) sustained the highest species losses, and species loss of forest ant, bird, and tree species increased with management intensity. Losses of ant and bird species were similar, although losses of forest ants were more drastic in rustic coffee. Richness of migratory birds and of birds that forage across vegetation strata was less affected by intensification than richness of resident, canopy, and understory bird species. Rustic farms protected more species than other coffee systems, and loss of species depended greatly on habitat specialization and functional traits. We recommend that forest be protected, rustic coffee be promoted, and intensive coffee farms be restored by augmenting native tree density and richness and allowing growth of epiphytes. We also recommend that future research focus on potential trade‐offs between biodiversity conservation and farmer livelihoods stemming from coffee production.  相似文献   

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Abstract:  We measured the net progress of land reform in achieving a national policy goal for biodiversity conservation in the context of ongoing clearing of native vegetation and additions of land to a highly nonrepresentative (residual) reserve network, interior South Island, New Zealand. We used systematic conservation-planning approaches to develop a spatially explicit index of risk of biodiversity loss (RBL). The index incorporated information from national data sets that describe New Zealand's remaining indigenous land cover, legal protection, and land environments and modeled risk to biodiversity on the basis of stated assumptions about the effects of past habitat loss and legal protection. The index identified irreplaceable and vulnerable native habitats in lowland environments as the most at risk of biodiversity loss, and risk was correlated with the density of threatened plant records. To measure achievement, we used changes in the index that reflected gains made and opportunity costs incurred by legal protection and privatization. Application of the index to measure the difference made by land reform showed it had caused a net increase in the risk of biodiversity loss because most land vulnerable to habitat modification and rich in threatened plant species was privatized and land at least risk of biodiversity loss was protected. The application revealed that new high-elevation reserves did little to mitigate biodiversity decline, that privatization of low-elevation land further jeopardized the most vulnerable biodiversity in lowland native habitats, and that outcomes of land reform for biodiversity deteriorated over time. Further development of robust achievement measures is needed to encourage more accountable biodiversity conservation decisions.  相似文献   

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湿地是陆地与水域之间的过渡地带,是地球上生产力最高的生态系统。湿地生态风险评价的实际应用将使人们更好地理解物理、化学和生物风险源如何影响湿地,并为湿地管理提供科学支撑,这就要求确定湿地生态健康评价指标的完整性。生物完整性指数以环境生态毒理学数据为依据,是进行生态系统健康风险评价的最有力工具。大中型无脊椎动物作为易选择的分类群,可用于湿地评估的生物完整性指数的建立,土壤动物特别是线虫类群作为湿地土壤和水环境健康评价的指示生物具有广阔前景。通过线虫分子毒理学等研究方法,可优化出生物完整性指数体系,建立扰动背景下的湿地生态风险评价模型,为湿地污染的监测、防控和修复,提供理论依据和实践方法。  相似文献   

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The successful conservation of biodiversity depends in part upon an accurate assessment of the diversity to be preserved. This assessment is in the domain of systematics, taxonomy, and general comparative biology. Specimens play a central role in this science, and research collections thus represent the touchstone of biodiversity. The massive job of describing and understanding avian diversity is far from complete, yet the specimen basis for much-needed work is not being added to our collections; current holdings are inadequate. The dwindling influx of specimens is due primarily to opposition to collecting, which is fueled by (1) focusing conservation at the level of the individual; (2) unfamiliarity with population biology; (3) misunderstanding of scientific research; (4) typological thinking; and (5) misplaced morality. Specimen-based avian research has a long and scientifically strong history, and the benefits of this research have been extensive. Our research collections must serve as functional biological libraries. The majority of avian populations can easily withstand the relatively tiny levels of collecting required to keep this science vigorous. Insofar as avian conservation necessarily includes the preservation of a myriad of species comprising the ecosystems upon which birds rely, this problem has broad implications for the conservation of biodiversity.  相似文献   

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Abstract: The new approaches advocated by the conservation community to integrate conservation and livelihood development now explicitly address landscape mosaics composed of agricultural and forested land rather than only protected areas and largely intact forests. We refer specifically to a call by Harvey et al. (2008) to develop a new approach based on six strategies to integrate biodiversity conservation with sustainable livelihoods in Mesoamerican landscape mosaics. We examined the applicability of this proposal to the coffee agroforests of the Western Ghats, India. Of the six strategies, only one directly addresses livelihood conditions. Their approach has a clear emphasis on conservation and, as currently formulated risks repeating the failures of past integrated conservation and development projects. It fails to place the aspirations of farmers at the core of the agenda. Thus, although we acknowledge and share the broad vision and many of the ideas proposed by this approach, we urge more balanced priority setting by emphasizing people as much as biodiversity through a careful consideration of local livelihood needs and aspirations.  相似文献   

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It is widely recognised that southwest Western Australia has experienced a decline in rainfall over the last 40 years. It is generally thought that this decline is due to natural periodic variations and changes induced by global warming, but recently evidence has emerged suggesting that a substantial part of the decline may be due to extensive logging close to the coast to make way for housing developments and the clearing of native vegetation for wheat planting on the higher ground. We compare coastal and inland rainfall to show empirically that 55% to 62% of the observed rainfall decline is the result of land clearing alone. Using the index of sustainable functionality, we show that the economic consequences associated with this change of land use on fresh water resource availability have been underestimated to date and disproportionately affect the environment and poorest members of the population.  相似文献   

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