Quantifying the degree of bias from using county‐scale data in species distribution modeling: Can increasing sample size or using county‐averaged environmental data reduce distributional overprediction?

Citizen‐science databases have been used to develop species distribution models (SDMs), although many taxa may be only georeferenced to county. It is tacitly assumed that SDMs built from county‐scale data should be less precise than those built with more accurate localities, but the extent of the bias is currently unknown. Our aims in this study were to illustrate the effects of using county‐scale data on the spatial extent and accuracy of SDMs relative to true locality data and to compare potential compensatory methods (including increased sample size and using overall county environmental averages rather than point locality environmental data). To do so, we developed SDMs in maxent with PRISM‐derived BIOCLIM parameters for 283 and 230 species of odonates (dragonflies and damselflies) and butterflies, respectively, for five subsets from the OdonataCentral and Butterflies and Moths of North America citizen‐science databases: (1) a true locality dataset, (2) a corresponding sister dataset of county‐centroid coordinates, (3) a dataset where the average environmental conditions within each county were assigned to each record, (4) a 50/50% mix of true localities and county‐centroid coordinates, and (5) a 50/50% mix of true localities and records assigned the average environmental conditions within each county. These mixtures allowed us to quantify the degree of bias from county‐scale data. Models developed with county centroids overpredicted the extent of suitable habitat by 15% on average compared to true locality models, although larger sample sizes (>100 locality records) reduced this disparity. Assigning county‐averaged environmental conditions did not offer consistent improvement, however. Because county‐level data are of limited value for developing SDMs except for species that are widespread and well collected or that inhabit regions where small, climatically uniform counties predominate, three means of encouraging more accurate georeferencing in citizen‐science databases are provided.     

Dipterocarp Biology as a Window to the Understanding of Tropical Forest Structure: Where are we Looking Now?

The dipterocarps are dominant trees across a large part of lowland Southeast Asia. These forests provide a valuable timber resource, are rich in biodiversity, and are among the most important terrestrial carbon sinks in the world. Yet, these forests are fast disappearing, often unsustainably managed and are rapidly being replaced by agricultural crops such as oil palm and other commercial plantations. Here, we provide a brief overview to this family, outline its significance, and introduce the articles of this Special Section which provides a collection of the recent advances in our understanding of the biology of this important family of tropical trees.     

The Sampled Red List Index for Plants,phase II: ground-truthing specimen-based conservation assessments

The IUCN Sampled Red List Index (SRLI) is a policy response by biodiversity scientists to the need to estimate trends in extinction risk of the world''s diminishing biological diversity. Assessments of plant species for the SRLI project rely predominantly on herbarium specimen data from natural history collections, in the overwhelming absence of accurate population data or detailed distribution maps for the vast majority of plant species. This creates difficulties in re-assessing these species so as to measure genuine changes in conservation status, which must be observed under the same Red List criteria in order to be distinguished from an increase in the knowledge available for that species, and thus re-calculate the SRLI. However, the same specimen data identify precise localities where threatened species have previously been collected and can be used to model species ranges and to target fieldwork in order to test specimen-based range estimates and collect population data for SRLI plant species. Here, we outline a strategy for prioritizing fieldwork efforts in order to apply a wider range of IUCN Red List criteria to assessments of plant species, or any taxa with detailed locality or natural history specimen data, to produce a more robust estimation of the SRLI.     

Response to De Silva et al. (2007): Endemic freshwater finfish of Asia: distribution and conservation status

De Silva et al . (2007) present an overview of the distribution and conservation status of the endemic freshwater fish of Asia. Within that review they use data from the IUCN Red List of Threatened Species™ (2006) to conduct an analysis of the conservation status of those endemic fish species. Their analysis is incorrect and provides a very misleading impression of the level of threat to Asian freshwater fish and to freshwater fish at the global scale. The errors stem from a misinterpretation of the data presented on the IUCN Red List. The sources of errors are discussed below and the opportunity is taken to clarify what the information on the IUCN Red List represents.     

The changing fates of the world's mammals

A recent complete assessment of the conservation status of 5487 mammal species demonstrated that at least one-fifth are at risk of extinction in the wild. We retrospectively identified genuine changes in extinction risk for mammals between 1996 and 2008 to calculate changes in the International Union for Conservation of Nature (IUCN) Red List Index (RLI). Species-level trends in the conservation status of mammalian diversity reveal that extinction risk in large-bodied species is increasing, and that the rate of deterioration has been most accelerated in the Indomalayan and Australasian realms. Expanding agriculture and hunting have been the main drivers of increased extinction risk in mammals. Site-based protection and management, legislation, and captive-breeding and reintroduction programmes have led to improvements in 24 species. We contextualize these changes, and explain why both deteriorations and improvements may be under-reported. Although this study highlights where conservation actions are leading to improvements, it fails to account for instances where conservation has prevented further deteriorations in the status of the world's mammals. The continued utility of the RLI is dependent on sustained investment to ensure repeated assessments of mammals over time and to facilitate future calculations of the RLI and measurement against global targets.     

生态系统红色名录——一种新的生物多样性保护工具

生物多样性为人类提供了生存所必需的一系列生态系统服务和功能。然而,由于人为活动的加剧,生物多样性不断丧失。传统的生物多样性保护主要关注物种多样性,存在着对生物多样性的代表性不足,不能及时反应生态系统多样性的变化等缺点。近年来,生态系统层次上的多样性保护成为研究热点,一些国家和组织相继开展了大尺度的生态系统评估工作。文章回顾了已有的生态系统评估方案,发现当前生态系统评估多采用IUCN物种红色名录的分级标准体系,主要评估生态系统的濒危程度,评估标准主要是分布范围和功能的变化,不同评估方案采用的指标和阈值有差异,需要建立统一的生态系统分类体系和评价方案。同时,结合国内生态系统评价的现状,提出了在我国开展生态系统红色名录研究的若干可行建议。     

What do mammalogists want to save? Ten years of mammalian conservation biology

Recent upsurge of interest in biological diversity requests that resources for conservation be allocated to taxonomic groups and geographic areas of greater priority, independent of the attractiveness of individual species. The aim of this paper is to assess if contributed papers on four of the most important international conservation journals in the last ten years reflect our increasing concern for threatened mammals. Our results show that some orders receive disproportionally more attention than predicted by their absolute number and percentage of threatened species. The Nearctic and Palearctic Regions are far more studied than other like, for instance, the Oriental Region, which are badly neglected considering their higher rates of endangered and endemic mammals. Furthermore, it was found that among many orders most of the species covered in contributed papers are not presently considered threatened by IUCN. Our work highlights the need of assessing conservation priorities at least at continental level and of devoting more resources to research in tropical countries.     

通过综合受威胁状态和保护价值评估云南省自然植被的保护优先性

植被保护优先性评估是保护规划制定和保护资源配置的重要基础。目前, 评估植被保护优先性的因子较为单一, 结合多因子系统性评估植被保护优先性的研究还很有限。本研究综合考虑植被受威胁状况和保护价值, 评估了云南省104类自然群系的保护优先性。首先, 根据IUCN生态系统红色名录评估框架评估群系受威胁状态; 然后, 选取濒危保护物种丰富度、冠层高度和碳储量3个指标, 加权计算各群系的生态系统质量以表征其保护价值; 最后, 通过综合受威胁状态与保护价值评估云南省自然植被的保护优先性, 并进一步划分为4个植被保护类型。研究结果表明: (1)在云南省104类群系中, 66.3%的群系受威胁等级为易危/濒危/极危(VU/EN/CR), 受到不同程度的威胁, 群系的分布范围受限是导致其受威胁的关键因素。(2) 45.2%的群系评估为高和极高保护价值, 38.5%的群系评估为中等保护价值, 植被质量整体较高。(3)综合评估建议: 保护价值高或极高且受威胁的31类群系进行优先保护; 保护价值中等但受威胁的26类群系进行次优先保护; 保护价值极高或高但未受威胁的16类群系进行预先保护; 其他群系进行一般保护。(4)云南省已建自然保护区对优先、次优先和预先保护植被的覆盖率分别为19.5%、9.7%和16.9%, 还存在一定的保护空缺。本研究构建的综合受威胁状态和保护价值的植被保护优先性评估方法, 能够为区域尺度生态系统水平的保护规划与行动提供科学支持。