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101.
Abstract: Local ecological knowledge can provide a unique source of data for conservation, especially in efforts to investigate the status of rare or possibly extinct species, but it is unlikely to remain constant over time. Loss of perspective about past ecological conditions caused by lack of communication between generations may create “shifting baseline syndrome,” in which younger generations are less aware of local species diversity or abundance in the recent past. This phenomenon has been widely discussed, but has rarely been examined quantitatively. We present new evidence of shifting baselines in local perception of regional species declines and on the duration of “community memory” of extinct species on the basis of extensive interviews with fishers in communities across the middle‐lower Yangtze basin. Many Yangtze species have experienced major declines in recent decades, and the Yangtze River dolphin or baiji (Lipotes vexillifer) and Yangtze paddlefish (Psephurus gladius) may have become extinct during the 21st century. Although informants across all age classes were strongly aware of the Yangtze ecosystem's escalating resource depletion and environmental degradation, older informants were more likely to recognize declines in two commercially important fish species, Reeves’ shad (Tenualosa reevesii) and Yangtze pufferfish (Takifugu fasciatus), and to have encountered baiji and paddlefish in the past. Age was also a strong predictor of whether informants had even heard of baiji or paddlefish, with younger informants being substantially less likely to recognize either species. A marked decrease in local knowledge about the Yangtze freshwater megafauna matched the time of major population declines of these species from the 1970s onwards, and paddlefish were already unknown to over 70% of all informants below the age of 40 and to those who first started fishing after 1995. This rapid rate of cultural baseline shift suggests that once even megafaunal species cease to be encountered on a fairly regular basis, they are rapidly forgotten by local communities.  相似文献   
102.
水厂抽水对乌什地震台体应变观测数据的干扰分析   总被引:1,自引:0,他引:1  
根据体应变的观测原理,从理论和实际观测中分析了水厂抽水对体应变观测分钟值曲线的影响及两者间的相关性.分析表明,应变观测值波动时间与抽水时间基本吻合,因此认为水厂抽水对体应变观测会造成一定程度的干扰.  相似文献   
103.
从某油污样品中分离、筛选出一株破乳菌株10#,经鉴定属芽孢杆菌属。该菌株对油田稳定O/W乳化液具明显的破乳效果。该菌株最佳培养条件为:温度30~35℃,pH7.0~7.5,生长时间48~72h,碳源为液体石蜡。该菌株在培养48h后具有明显而稳定的破乳效果,破乳活性部位为菌体。  相似文献   
104.
为分析洪泽湖流域洪涝灾害在千年尺度序列上的演变趋势,采用统计历史洪涝记录的方法,分析了气候变化背景下洪涝灾害的响应过程,探讨了洪泽湖流域洪涝灾害同El Ni(n)o事件的关系.结果表明:近1 000 a来洪泽湖流域洪涝灾害的频度总体是趋于上升的,这种变化趋势同气候变化的趋势是一致的.研究结果显示:公元1000~1400年洪涝记录偏少,同我国东部地区尤其是中世纪暖期出现的一次200 a以上的干旱化过程有较好的对应性.1400~1800年是洪泽湖流域洪涝的多发期,这一事实同我国东部1550~1850年小冰期期间总体偏湿的环境特征相一致.分析洪涝灾害变化同El Ni(n)o事件对应性关系表明:在El Ni(n)o事件年及其次年是洪泽湖流域洪涝的多发年份.这可能是由于El Ni(n)o事件通过改变西太平洋副高的强度与位置,以及大气环流形势而引起的降水异常所致.了解洪泽湖流域洪涝的演变趋势及其同El Ni(n)o的关系对于长期防灾减灾策略具有重要的参考意义.  相似文献   
105.
Infrastructure development is a major driver of biodiversity loss globally. With upward of US$2.5 trillion in annual investments in infrastructure, the financial sector indirectly drives this biodiversity loss. At the same time, biodiversity safeguards (project-level biodiversity impact mitigation requirements) of infrastructure financiers can help limit this damage. The coverage and harmonization of biodiversity safeguards are important factors in their effectiveness and therefore warrant scrutiny. It is equally important to examine the extent to which these safeguards align with best-practice principles for biodiversity impact mitigation outlined in international policies, such as that of the International Union for Conservation of Nature. We assessed the biodiversity safeguards of public development banks and development finance institutions for coverage, harmonization, and alignment with best practice. We used Institute of New Structural Economics and Agence Française de Développement's global database to identify development banks that invest in high-biodiversity-footprint infrastructure and have over US$500 million in assets. Of the 155 banks, 42% (n = 65) had biodiversity safeguards. Of the existing safeguards, 86% (56 of 65) were harmonized with International Finance Corporation (IFC) Performance Standard 6 (PS6). The IFC PS6 (and by extension the 56 safeguard policies harmonized with it) had high alignment with international best practice in biodiversity impact mitigation, whereas the remaining 8 exhibited partial alignment, incorporating few principles that clarify the conditions for effective biodiversity offsetting. Given their dual role in setting benchmarks and leveraging private finance, infrastructure financiers in development finance need to adopt best-practice biodiversity safeguards if the tide of global biodiversity loss is to be stemmed. The IFC PS6, if strengthened, can act as a useful template for other financier safeguards. The high degree of harmonization among safeguards is promising, pointing to a potential for diffusion of practices.  相似文献   
106.
Abstract: Understanding the ecological mechanisms that lead to extinction is a central goal of conservation. Can understanding ancient avian extinctions help to predict extinction risk in modern birds? I used classification trees trained on both paleoecological and historical data from islands across the Pacific to determine the ecological traits associated with extinction risk. Intrinsic traits, including endemism, large body size, and certain feeding guilds, were tightly linked with avian extinction over the past 3500 years. Species ecology and phylogeny were better predictors of extinction risk through time than extrinsic or abiotic factors. Although human impacts on birds and their habitats have changed over time, modern endangered birds share many of the same ecological characteristics as victims of previous extinction waves. My use of detailed predictions of extinction risk to identify species potentially in need of conservation attention demonstrates the utility of paleoecological knowledge for modern conservation biology.  相似文献   
107.
Significant challenges remain in the ability to estimate habitat change under the combined effects of natural variability, climate change, and human activity. We examined anticipated effects on shallow water over low‐sloped beaches to these combined effects in the lower Willamette River, Oregon, an area highly altered by development. A proposal to stabilize some shoreline with large rocks (riprap) would alter shallow water areas, an important habitat for threatened Chinook salmon (Oncorhynchus tshawytscha), and would be subject to U.S. Endangered Species Act‐mandated oversight. In the mainstem, subyearling Chinook salmon appear to preferentially occupy these areas, which fluctuate with river stages. We estimated effects with a geospatial model and projections of future river flows. Recent (1999–2009) median river stages during peak subyearling occupancy (April–June) maximized beach shallow water area in the lower mainstem. Upstream shallow water area was maximized at lower river stages than have occurred recently. Higher river stages in April–June, resulting from increased flows predicted for the 2080s, decreased beach shallow water area 17–32%. On the basis of projected 2080s flows, more than 15% of beach shallow water area was displaced by the riprap. Beach shallow water area lost to riprap represented up to 1.6% of the total from the mouth to 12.9 km upstream. Reductions in shallow water area could restrict salmon feeding, resting, and refuge from predators and potentially reduce opportunities for the expression of the full range of life‐history strategies. Although climate change analyses provided useful information, detailed analyses are prohibitive at the project scale for the multitude of small projects reviewed annually. The benefits of our approach to resource managers include a wider geographic context for reviewing similar small projects in concert with climate change, an approach to analyze cumulative effects of similar actions, and estimation of the actions’ long‐term effects. Efectos Combinados del Cambio Climático y la Estabilización de Bordes de Ríos Hábitats de Aguas Poco Profundas del Salmón Chinook  相似文献   
108.
Ecological distance-based spatial capture–recapture models (SCR) are a promising approach for simultaneously estimating animal density and connectivity, both of which affect spatial population processes and ultimately species persistence. We explored how SCR models can be integrated into reserve-design frameworks that explicitly acknowledge both the spatial distribution of individuals and their space use resulting from landscape structure. We formulated the design of wildlife reserves as a budget-constrained optimization problem and conducted a simulation to explore 3 different SCR-informed optimization objectives that prioritized different conservation goals by maximizing the number of protected individuals, reserve connectivity, and density-weighted connectivity. We also studied the effect on our 3 objectives of enforcing that the space-use requirements of individuals be met by the reserve for individuals to be considered conserved (referred to as home-range constraints). Maximizing local population density resulted in fragmented reserves that would likely not aid long-term population persistence, and maximizing the connectivity objective yielded reserves that protected the fewest individuals. However, maximizing density-weighted connectivity or preemptively imposing home-range constraints on reserve design yielded reserves of largely spatially compact sets of parcels covering high-density areas in the landscape with high functional connectivity between them. Our results quantify the extent to which reserve design is constrained by individual home-range requirements and highlight that accounting for individual space use in the objective and constraints can help in the design of reserves that balance abundance and connectivity in a biologically relevant manner.  相似文献   
109.
The environmental degradation of urban rivers and streams in large cities has led to the development of a variety of public policies. In the city of São Paulo, Brazil, a policy for recovering watercourses and valley floors has been developed with the implementation of riverside parks. This represents a new paradigm for the city in terms of its relationship with rivers and streams. This paper presents the results of an exploratory study, which aimed to analyse riverside parks in the city of São Paulo during the last decade. The study analysed the main management difficulties in relation to these types of urban park during their post-implementation stage, assessing their performance in relation to their social and environmental functions. It addressed issues such as the state of the site before and after the implementation of the riverside park, levels of user satisfaction in relation to the state of the watercourse, sports and leisure facilities, green space, security and the way the park is used. The study showed that riverside parks are recognised as elements that improve the quality of public spaces, socially legitimised as public policies.  相似文献   
110.
Abstract: The introduction of non‐native plant species and the release of genetically modified (GM) crops can induce environmental changes at gene to ecosystem levels. Regulatory frameworks such as the Convention on Biological Diversity or the EU Deliberate Release Directive aim to prevent environmental damage but do not define the term. Although ecologists and conservationists often refer to environmental effects of GM crops or invasive species as damage, most authors do not disclose their normative assumptions or explain why some environmental impacts are regarded as detrimental and others are not. Thus far, a concise definition of environmental damage is missing and is necessary for a transparent assessment of environmental effects or risks. Therefore, we suggest defining environmental damage as a significant adverse effect on a biotic or abiotic conservation resource (i.e., a biotic or abiotic natural resource that is protected by conservational or environmental legislation) that has an impact on the value of the conservation resource, the conservation resource as an ecosystem component, or the sustainable use of the conservation resource. This definition relies on three normative assumptions: only concrete effects on a conservation resource can be damages; only adverse effects that lead to a decrease in the value of the conservation resource can be damages; and only significant adverse effects constitute damage to a conservation resource. Applying this definition within the framework of environmental risk assessment requires further normative determinations, for example, selection of a threshold to distinguish between adverse and significant adverse effects and approaches for assessing the environmental value of conservation resources. Such determinations, however, are not part of the definition of environmental damage. Rather they are part of the definition's operationalization through assessment procedures, which must be grounded in a comprehensible definition of environmental damage.  相似文献   
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