Predicting how populations decline to extinction

Global species extinction typically represents the endpoint in a long sequence of population declines and local extinctions. In comparative studies of extinction risk of contemporary mammalian species, there appear to be some universal traits that may predispose taxa to an elevated risk of extinction. In local population-level studies, there are limited insights into the process of population decline and extinction. Moreover, there is still little appreciation of how local processes scale up to global patterns. Advancing the understanding of factors which predispose populations to rapid declines will benefit proactive conservation and may allow us to target at-risk populations as well as at-risk species. Here, we take mammalian population trend data from the largest repository of population abundance trends, and combine it with the PanTHERIA database on mammal traits to answer the question: what factors can be used to predict decline in mammalian abundance? We find in general that environmental variables are better determinants of cross-species population-level decline than intrinsic biological traits. For effective conservation, we must not only describe which species are at risk and why, but also prescribe ways to counteract this.     

生物多样性监测指标体系构建研究进展

生物多样性监测是为确定与预期标准相一致或相背离的程度,而对生物多样性进行定期或不定期的监视,目前已成为生物多样性研究和保护的热点问题。生物多样性监测指标则是一些简化的生物或环境特征参数,说明生物多样性现状和变化趋势,以及人类活动压力对生物多样性的影响,以促进科学界、政府和公众间的沟通,提高生物多样性管理水平。近10年来,国际组织、政府机构和各国学者对生物多样性指标体系的构建进行了大量的探索工作,取得了很多进展,其中有些指标已经应用于实际监测项目。本文综述了生物多样性监测指标筛选的一般标准和指标体系构建的主要理论,梳理目前已提出或应用的主要生物多样性监测指标,以期为我国构建国家或区域尺度生物多样性监测指标体系提供参考。在此基础上分析提出：生物多样性概念的泛化、指标含义模糊以及知识和数据的缺乏是构建生物多样性监测指标的主要困难。我国未来的生物多样性监测指标体系构建需要关注以下两个方面：（1）紧密联系实际,构建适应性的监测指标体系,加强对典型生态系统区域的监测;（2）发展经济社会发展方面的指标,分析生物多样性变化的驱动力,为生物多样性保护和区域可持续发展提供科学依据。     

Improving the objectivity of sustainability indices by a novel approach for combining contrasting effects: Happy Planet Index revisited

Measuring complex and rather intuitive qualities such as sustainability requires combining many different measures together. These measures often quantify contrasting effects. The resulting composite index then also depends not only on the component indices but also on the way that these have been combined together. An example of such a measure is the Happy Planet Index (HPI) that aggregates information on positive qualities like life-expectancy and human well-being with negative ones like ecological footprint to rank countries according to their sustainability. However, since component indices are often mutually correlated and feature quite different distributions of entities ranked, elaborate rules are used in the process of combination. As a result, the resulting composite index may look somewhat contrived and its rankings may depend heavily on subjective parameters in the combination process. We propose a geometrically motivated parameter-free method for combining indices with contrasting effects together. The method is independent of the number of contrasting indices to be combined and eliminates mutual correlation between component indices by using Singular Value Decomposition (SVD) analysis. As an example of its use, we revisit the Happy Planet Index and demonstrate the impact of adding new component indices to HPI on ranking nations by their sustainability.     

追踪物种丧失•聚焦生态超载•共享一个地球——《2006地球生命力报告》解读

世界自然基金会和环球足迹网络等2006年10月在中国北京联合发布《2006地球生命力报告》,用生命地球指数和生态足迹两个主要指标描绘了全球生物多样性的变化状态和人类所面临的环境压力。报告显示：生命地球指数1970~2003年总体下降约三分之一,其中陆栖指数减少约31％、海洋指数减少约27％、淡水指数减少约30％,生物多样性正快速持续地遭到损失;自1961年人类的生态足迹不断增加,1987年转入生态赤字下运行,此后生态超载不断加剧,2003年生态赤字达25.28％;化石燃料足迹增长最快,2003年几乎占到一半,达到48%;阿联酋、美国、加拿大等国家人均足迹最大,阿富汗最小,中国排名69位;北美、欧盟、中东和中亚、亚太区处于生态超载状态,非欧联盟、拉丁美洲和加勒比海地区、非洲处于生态盈余;过去40多年,人均足迹高收入国家增长2倍多,2003年达6.5 gha,低收入国家一直在0.8 gha以下徘徊,中收入国家也从未超过2.0 gha。地球的经济怎样才可能在过度消耗中持续发展？3种预测情景也许会让我们走出生态超载的困境、走向可持续发展,共享“一个地球生活”的美好未来。整篇报告可以概括为4个主题：追踪物种丧失、聚焦生态超载、3种情景预测、一个地球生活。     

追踪物种丧失•聚焦生态超载•共享一个地球——《2006地球生命力报告》解读

世界自然基金会和环球足迹网络等2006年10月在中国北京联合发布《2006地球生命力报告》,用生命地球指数和生态足迹两个主要指标描绘了全球生物多样性的变化状态和人类所面临的环境压力。报告显示:生命地球指数1970～2003年总体下降约三分之一,其中陆栖指数减少约31%、海洋指数减少约27%、淡水指数减少约30%,生物多样性正快速持续地遭到损失;自1961年人类的生态足迹不断增加,1987年转入生态赤字下运行,此后生态超载不断加剧,2003年生态赤字达25.28%;化石燃料足迹增长最快,2003年几乎占到一半,达到48%;阿联酋、美国、加拿大等国家人均足迹最大,阿富汗最小,中国排名69位;北美、欧盟、中东和中亚、亚太区处于生态超载状态,非欧联盟、拉丁美洲和加勒比海地区、非洲处于生态盈余;过去40多年,人均足迹高收入国家增长2倍多,2003年达6.5gha,低收入国家一直在0.8gha以下徘徊,中收入国家也从未超过2.0gha。地球的经济怎样才可能在过度消耗中持续发展?3种预测情景也许会让我们走出生态超载的困境、走向可持续发展,共享\"一个地球生活\"的美好未来。整篇报告可以概括为4个主题:追踪物种丧失、聚焦生态超载、3种情景预测、一个地球生活。     

Are the variables used in building composite indicators of well-being relevant? Validating composite indexes of well-being

This paper explores the relevance of the variables that define well-being and human progress and makes a quantitative inquiry into the validity of three of the well-known and well-documented composite indicators of well-being: the Human Development Index (HDI), the Legatum Prosperity Index (LPI) and the Happy Planet Index (HPI). After choosing the key variables that describe most of the objective and subjective dimensions of well-being, we perform cluster analysis to come up with an optimal grouping of countries based on their multidimensional performance on well-being. A comparison of the classifications obtained with the three indexes invalidates the HPI, confirms results obtained for the HDI, and validates for the first time the LPI as a reliable measure of well-being. The optimal cluster structure yields robust results, which correct the rank discrepancies between the HDI and LPI for a large number of countries. It also proves that a robust ranking of countries based on multidimensional well-being can be achieved with a relatively small number of variables, which mitigates the risk of including variables that are not reliable and/or not available for a significant number of countries. The fact that cluster analysis generates results based on similarities between observations and not on computed values based on the aggregation of variables helps overcome problems that may occur due to the distribution of variables and increases its value as a validation method. Therefore, validation results achieved through cluster analysis are more robust and help to achieve a good check of the validity and relevance of the composite indexes, provide an objective perspective that can guide policy-makers and the public in making a fair assessment of actual levels of well-being, and avoid unfounded claims that may overstate it and delay or postpone measures to increase it.     

The selection, testing and application of terrestrial insects as bioindicators

Although the uses and merits of terrestrial insects as indicators have been extensively discussed, there is a lack of clear definition, goal directedness and hypothesis testing in studies in the field. In an attempt to redress some of these issues and outline an approach for further studies, three categories of terrestrial insect indicators, corresponding to differences in their application, are proposed, i.e. environmental, ecological and biodiversity indicators. The procedures in terrestrial insect bioindicator studies should start with a clear definition of the study objectives and proposed use of the bioindicator, as well as with a consideration of the scale at which the study is to be carried out. Bioindication studies are conducted at a variety of spatial and temporal scales within the context of earth-system processes, but the objectives of the study will largely determine the scale at which it would be optimally conducted. There is a tendency for studies to be conducted below their space-time scaling functions, giving them apparent predictability. The selection of potential indicator taxa or groups is then based on a priori suitability criteria, the identification of predictive relationships between the indicator and environmental variables and, most importantly, the development and testing of hypotheses according to the correlative patterns found. Finally, recommendations for the use of the indicator in monitoring should be made. Although advocating rigorous, long-term protocols to identify indicators may presently be questionable in the face of the urgency with which conservation decisions have to be made, this approach is critical if bioindicators are to be used with any measurable degree of confidence.     

生物物种资源监测原则与指标及抽样设计方法

生物物种资源监测是了解生物物种资源现状、开展生物物种资源保护与管理的基础工作和重要手段.阐述了生物物种资源监测的科学性原则、可操作性原则和持续性原则.提出了监测计划的制定程序;监测计划应充分考虑所具有的人力、资金和后勤保障等条件,并进行定期评估.分析了指示物种在物种资源监测中的作用与不足;认为应选择具有不同生态需求和生活史的生物类群作为监测对象.讨论了监测指标的选取方法;监测指标应可测量、有科学基础、易被公众接受、低成本和高效益;监测方法应具有科学性,能检测到相应的变化,应采用高效率、低成本的标准化监测方法.分析了现有监测计划在抽样设计方面存在的问题,探讨了空间变异性和可检测率对监测数据误差的影响及其处理方式,讨论了样本量确定和监测样地的大小、形状及位置设计.监测样地要有较好的代表性,能在有限的监测面积中较好地反映监测区域内群落种类组成与数量特征.最后,讨论了生物物种资源监测的尺度和标准化问题.