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191.
To determine the distribution and causes of extinction threat across functional groups of terrestrial vertebrates, we assembled an ecological trait data set for 18,016 species of terrestrial vertebrates and utilized phylogenetic comparative methods to test which categories of habitat association, mode of locomotion, and feeding mode best predicted extinction risk. We also examined the individual categories of the International Union for Conservation of Nature Red List extinction drivers (e.g., agriculture and logging) threatening each species and determined the greatest threats for each of the four terrestrial vertebrate groups. We then quantified the sum of extinction drivers threatening each species to provide a multistressor perspective on threat. Cave dwelling amphibians (p < 0.01), arboreal quadrupedal mammals (all of which are primates) (p < 0.01), aerial and scavenging birds (p < 0.01), and pedal (i.e., walking) squamates (p < 0.01) were all disproportionately threatened with extinction in comparison with the other assessed ecological traits. Across all threatened vertebrate species in the study, the most common risk factors were agriculture, threatening 4491 species, followed by logging, threatening 3187 species, and then invasive species and disease, threatening 2053 species. Species at higher risk of extinction were simultaneously at risk from a greater number of threat types. If left unabated, the disproportionate loss of species with certain functional traits and increasing anthropogenic pressures are likely to disrupt ecosystem functions globally. A shift in focus from species- to trait-centric conservation practices will allow for protection of at-risk functional diversity from regional to global scales.  相似文献   
192.
As a passive remote sensing technique, MAX-DOAS method was widely used to investigate the vertical profiles of aerosol and trace gases in the lower troposphere. However, the measurements for midlatitude marine boundary layer are rarely reported, especially during the storm weather system. In this study, the MAX-DOAS was used to retrieve the aerosol, HCHO and NO2 vertical distribution at Huaniao Island of East China Sea in summer 2018, during which a strong tropical cyclone developed and passed through the measurement site. The observed aerosol optical depth (AOD), HCHO- and NO2-VCDs (Vertical Column Density) were in the range of 0.19-0.97, (2.57-12.27) × 1015 molec/cm2, (1.24-4.71) × 1015 molec/cm2, which is much higher than remote ocean area due to the short distance to continent. The vertically resolved aerosol extinction coefficient (AEC), HCHO and NO2 presented the decline trend with the increase of height. After the typhoon passing through, the distribution of high levels of aerosol and HCHO stretched to about 1 km and the abundances of the bottom layer were found as double higher than before, reaching 0.51 km−1 and 2.44 ppbv, while NO2 was still constrained within about 300 m with 2.59 ppbv in the bottom layer. The impacts of typhoon process forced air mass were also observed at the suburban site in Shanghai in view of both the aerosol extinction and chemical components. The different changes on air quality associated with typhoon and its mechanism in two different environments: coastal island and coastal city are worthy of further investigation as it frequent occurred in East Asia during summer and fall.  相似文献   
193.
Abstract: The Iberian lynx (Lynx pardinus) may be the first charismatic felid to become extinct in a high‐income country, despite decades of study and much data that show extinction is highly probable. The International Union for Conservation of Nature categorizes it as critically endangered; about 200 free‐ranging individuals remain in two populations in southern Spain. Conservation measures aimed at averting extirpation have been extensively undertaken with 4 of the former 10 Iberian lynx populations recorded 25 years ago. Two of the four populations have been extirpated. The number of individuals in the third population have declined by 83%, and in the fourth the probability of extirpation has increased from 34% to 95%. Major drivers of the pending extinction are the small areas to which conservation measures have been applied; lack of incorporation of evidence‐based conservation, scientific monitoring, and adaptive management into conservation efforts; a lack of continuity in recovery efforts, and distrust by conservation agencies of scientific information. In contrast to situations in which conservation and economic objectives conflict, in the case of the Iberian lynx all stakeholders desire the species to be conserved.  相似文献   
194.
Abstract: Climate change affects individual organisms by altering development, physiology, behavior, and fitness, and populations by altering genetic and phenotypic composition, vital rates, and dynamics. We sought to clarify how selection, phenotypic plasticity, and demography are linked in the context of climate change. On the basis of theory and results of recent empirical studies of plants and animals, we believe the ecological and evolutionary issues relevant to population persistence as climate changes are the rate, type, magnitude, and spatial pattern of climate‐induced abiotic and biotic change; generation time and life history of the organism; extent and type of phenotypic plasticity; amount and distribution of adaptive genetic variation across space and time; dispersal potential; and size and connectivity of subpopulations. An understanding of limits to plasticity and evolutionary potential across traits, populations, and species and feedbacks between adaptive and demographic responses is lacking. Integrated knowledge of coupled ecological and evolutionary mechanisms will increase understanding of the resilience and probabilities of persistence of populations and species.  相似文献   
195.
196.
Abstract:  For successful conservation of species it is important to identify traits that predispose species to the risk of extinction. By identifying such traits conservation efforts can be directed toward species that are most at risk of becoming threatened. We used data derived from the literature to determine ecological traits that affect distribution, distribution change, and the risk of extinction in Finnish noctuid moths (Lepidoptera, Noctuidae). The ecological traits we examined included body size, larval specificity, length of the flight period, and overwintering stage. In addition, in monophagous species we examined the effects of resource distribution. Larval specificity, length of the flight period, and the overwintering stage each had an independent effect on the risk of extinction when the effects of other traits were controlled by entering all traits into the same regression model. Not a single trait predicted the risk of extinction when analysis was conducted without controlling for the other traits. This discrepancy among the results suggests that a single trait may not be enough to allow prediction of the risk of extinction. Instead, it seems that for successful, predictive conservation science data on several ecological characteristics are needed.  相似文献   
197.
198.
2010年1月北京城区大气消光系数重建及其贡献因子   总被引:7,自引:5,他引:2  
于2010年1月1~31日在北京城区每天采集PM2.5样品.利用热光碳分析仪、离子色谱和X荧光光谱仪分别分析样品中有机碳/元素碳、水溶性离子和土壤元素,同步收集了大气散射系数(bsp)、吸收系数(bap)和气象数据.利用IMPROVE方程重建大气消光系数,并与实测大气消光系数进行对比.结果发现,PM2.5日均值质量浓度为(144.3±89.1)μg.m-3,实测值bap、bsp和消光系数(bext)分别为(67.4±54.3)、(328.5±353.8)和(395.9±405.2)Mm-1.IMPROVE方程适用于观测期间北京大气消光系数的解析.观测期间计算值b’ext均值为(611±503)Mm-1,(NH4)2SO4、NH4NO3、OM、EC和FS对b’ext的贡献分别为24.6%、11.6%、45.5%、11.9%和6.4%.  相似文献   
199.
利用2009—2013年冬季地面气象观测数据筛选出非霾和不同强度霾的影响时次,采用能见度与消光系数的定量关系和冬季波长系数对微霾冲激光雷达反演修正得到的气溶胶消光系数,分析了上海地区气溶胶在垂直高度上的集中范围,当地面出现轻微霾、轻度霾、中度霾、重度霾时气溶胶分别主要集中于近地面0.81、0.49、0.41、0.40 km以下,非霾时气溶胶主要集中在近地面1.35 km以下;在此基础上,根据判别不同强度霾的能见度标准和能见度与消光系数的定量关系,将能见度换算为消光系数,再对微脉冲激光雷达反演消光系数进行修正,从而判断高空霾的强度及所处的高度;另外还探讨了云对产生重度霾的影响、降水与中度霾和重度霾的关系以及颗粒物质量浓度与不同强度霾的关系,发现48.53%的重度霾是受云影响而产生的,37.11%中度霾发生前后伴有降水现象,51.14%的重度霾发生前后伴有降水现象,非霾、轻微霾,轻度霾、中度霾、重度霾期间的颗粒物浓度和细颗粒物占的比例依次增大.  相似文献   
200.
The Endangered Species Act (ESA) of the United States was enacted in 1973 to prevent the extinction of species. Recovery plans, required by 1988 amendments to the ESA, play an important role in organizing these efforts to protect and recover species. To improve the use of science in the recovery planning process, the Society for Conservation Biology (SCB) commissioned an independent review of endangered species recovery planning in 1999. From these findings, the SCB made key recommendations for how management agencies could improve the recovery planning process, after which the U.S. Fish and Wildlife Service and the National Marine Fisheries Service redrafted their recovery planning guidelines. One important recommendation called for recovery plans to make threats a primary focus, including organizing and prioritizing recovery tasks for threat abatement. We sought to determine the extent to which results from the SCB study were incorporated into these new guidelines and whether the SCB recommendations regarding threats manifested in recovery plans written under the new guidelines. Recovery planning guidelines generally incorporated the SCB recommendations, including those for managing threats. However, although recent recovery plans have improved in their treatment of threats, many fail to adequately incorporate threat monitoring. This failure suggests that developing clear guidelines for monitoring should be an important priority in improving ESA recovery planning.  相似文献   
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