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1.
Conservation policies and environmental impact assessments commonly target threatened species and habitats. Nevertheless, macroecological research provides reasons why also common species should be considered. We investigate the consequences of focussing solely on legally protected species and habitats in a spatial conservation planning context using a comprehensive, benthic marine data set from the northern Baltic Sea. Using spatial prioritization and surrogacy analysis, we show that the common approach in conservation planning, where legally listed threatened species and habitats are the focus of conservation efforts, could lead to poor outcomes for common species (and therefore biodiversity as a whole), allowing them to decline in the future. If conservation efforts were aimed solely at threatened species, common species would experience a loss of 62% coverage. In contrast, if conservation plans were based only on common species, threatened species would suffer a loss of 1%. Threatened species are rare and their ecological niches distinct, making them poor surrogates for biodiversity. The best results are achieved by unified planning for all species and habitats. The minimal step towards acknowledging common species in conservation planning would be the inclusion of the richness of common species, complemented by information on indicator species or species of high importance for ecosystem functioning. The trade-off between planning for rare and common species should be evaluated, to minimize losses to biodiversity.  相似文献   

2.
Indicator species groups are often used as surrogates for overall biodiversity in conservation planning because inventories of multiple taxa are rare, especially in the tropics where most biodiversity is found. At coarse spatial scales most studies show congruence in the distribution of species richness and of endemic and threatened species of different species groups. At finer spatial scale levels however, cross-taxon congruence patterns are much more ambiguous. In this study we investigated cross-taxon patterns in the distribution of species richness of trees, birds and bats across four tropical forest types in a ca. 100 × 35 km area in the Northern Sierra Madre region of Luzon Island, Philippines. A non-parametric species richness estimator (Chao1) was used to compensate for differential sample sizes, sample strategies and completeness of species richness assessments. We found positive but weak congruence in the distribution of all and endemic tree and bird and tree and bat species richness across the four forest types; strong positive congruence in the distribution of all and endemic bat and bird species richness and low or negative congruence in the distribution of globally threatened species between trees, birds and bats. We also found weak cross-taxon congruence in the complementarity of pairs of forest types in species richness between trees and birds and birds and bats but strong congruence in complementarity of forest pairs between trees and bats. This study provides further evidence that congruence in the distribution of different species groups is often ambiguous at fine to moderate spatial scales. Low or ambiguous cross-taxon congruence complicates the use of indicator species and species groups as a surrogate for biodiversity in general for local systematic conservation planning.  相似文献   

3.
The urgent need to conserve aquatic biodiversity and the lack of spatial data on biodiversity has motivated conservation planners and researchers to search for more readily obtainable information that could be used as proxies or surrogates. The surrogate taxon approach shows promise in some aquatic environments (e.g. intertidal) but not others (e.g. coral reefs, temperate rocky reefs). Estuaries are transitional environments at the land–sea junction with a unique biodiversity, but are the most threatened of aquatic environments because of high levels of human use. The comparatively small numbers of conservation reserves means that estuarine biodiversity is poorly protected. Selecting additional conservation reserves within estuaries would be facilitated by the identification of a suitable surrogate that could be used in conservation planning. In one estuary in Southeast Australia, we evaluated separately the effectiveness of annelids, arthropods, and molluscs as surrogates for predicting the species richness, abundance, assemblage variation, and summed irreplaceability of other species and for coincidentally representing other species in networks of conservation reserves selected for each surrogate. Spatial patterns in the species richness and assemblage variation (but not summed irreplaceability) of each surrogate were significantly correlated with the spatial patterns of other species. The total abundance of annelids and the total abundance of arthropods were each significantly correlated with the total abundances of other species. Networks of conservation reserves selected to represent each surrogate performed significantly better than random selection in representing other species. The greatest number of non-surrogate species was coincidentally included in reserves selected for the group of mollusc species. We conclude that annelids and arthropods are effective surrogate taxa for identifying spatial variation in several measures of conservation value (species richness, abundance, assemblage variation) in estuaries. We also conclude that spatial data on annelids, arthropods or molluscs can be used to select networks of conservation reserves in estuaries. The demonstrated effectiveness of these surrogates should facilitate future conservation planning within estuaries.  相似文献   

4.
There is a long tradition of grazing by semi‐domestic reindeer and sheep in alpine and sub‐alpine Scandinavian habitats, but present management regimes are questioned from a conservation point of view. In this review we discuss plant diversity patterns in the Scandinavian mountains in a global, regional and local perspective. The main objective was to identify processes that influence diversity at different spatial scales with a particular focus on grazing. In a global perspective the species pool of the Scandinavian mountains is limited. partly reflecting the general latitudinal decline of species but also historical and ecological factors operating after the latest glaciation. At the local scale, both productivity and disturbance are primary factors structuring diversity, but abiotic factors such as soil pH, snow distribution and temperature are also important. Although evidence is scarce, grazing favours local species richness in productive habitats, whereas species richness decreases with grazing when productivity is low. Regional patterns of plant diversity is set by, 1) the species pool. 2) the heterogeneity and fragmentation of communities, and 3) local diversity of each plant community. We suggest that local shifts in community composition depend both on the local grazing frequency and the return‐time of the plant community after a grazing session. In addition, an increasing number of grazing‐modified local patches homogenises the vegetation and is likely to reduce the regional plant diversity. The time scale of local shifts in community composition depends on plant colonisation and persistence, From a mechanistic point of view, diversity patterns at a regional scale also depend on the regional dynamics of single species. Colonisation is usually a slow and irregular process in alpine environments, whereas the capacity for extended local persistence is generally high. Although the poor knowledge of plant regional dynamics restricts our understanding of how grazing influences plant diversity, we conclude that grazing is a key process for maintaining biodiversity in the Scandinavian mountains.  相似文献   

5.
Threats and biodiversity in the mediterranean biome   总被引:1,自引:0,他引:1  
Aim Global conservation assessments recognize the mediterranean biome as a priority for the conservation of the world's biodiversity. To better direct future conservation efforts in the biome, an improved understanding of the location, magnitude and trend of key threats and their relationship with species of conservation importance is needed. Location Mediterranean‐climate regions in California‐Baja California, Chile, South Africa, Australia and the Mediterranean Basin. Methods We undertook a systematic, pan‐regional assessment of threats in the mediterranean biome including human population density, urban area and agriculture. To realize the full implications of these threats on mediterranean biodiversity, we examined their relationship with species of conservation concern: threatened mammals at the global scale and threatened plants at the subecoregional scale in California, USA. Results Across the biome, population density and urban area increased by 13% and agriculture by 1% between 1990 and 2000. Both population density and urban area were greatest in California‐Baja California and least in Australia while, in contrast, agriculture was greatest in Australia and least in California‐Baja California. In all regions lowlands were most affected by the threats analysed, with the exception of population density in the Chilean matorral. Threatened species richness had a significant positive correlation with population density at global and subecoregional scales, while threatened species were found to increase with the amount of urban area and decrease as the amount of natural area and unfragmented core area increased. Main conclusions Threats to mediterranean biodiversity have increased from 1990 to 2000, although patterns vary both across and within the five regions. The need for future conservation efforts is further underlined by the positive correlation between species of conservation concern and the increase in population density over the last decade. Challenges to reducing threats extend beyond those analysed to include human–environmental interactions and their synergistic effects, such as urbanization and invasive species and wildfires.  相似文献   

6.
Conservation planners represent many aspects of biodiversity by using surrogates with spatial distributions readily observed or quantified, but tests of their effectiveness have produced varied and conflicting results. We identified four factors likely to have a strong influence on the apparent effectiveness of surrogates: (1) the choice of surrogate; (2) differences among study regions, which might be large and unquantified (3) the test method, that is, how effectiveness is quantified, and (4) the test features that the surrogates are intended to represent. Analysis of an unusually rich dataset enabled us, for the first time, to disentangle these factors and to compare their individual and interacting influences. Using two data-rich regions, we estimated effectiveness using five alternative methods: two forms of incidental representation, two forms of species accumulation index and irreplaceability correlation, to assess the performance of ‘forest ecosystems’ and ‘environmental units’ as surrogates for six groups of threatened species—the test features—mammals, birds, reptiles, frogs, plants and all of these combined. Four methods tested the effectiveness of the surrogates by selecting areas for conservation of the surrogates then estimating how effective those areas were at representing test features. One method measured the spatial match between conservation priorities for surrogates and test features. For methods that selected conservation areas, we measured effectiveness using two analytical approaches: (1) when representation targets for the surrogates were achieved (incidental representation), or (2) progressively as areas were selected (species accumulation index). We estimated the spatial correlation of conservation priorities using an index known as summed irreplaceability. In general, the effectiveness of surrogates for our taxa (mostly threatened species) was low, although environmental units tended to be more effective than forest ecosystems. The surrogates were most effective for plants and mammals and least effective for frogs and reptiles. The five testing methods differed in their rankings of effectiveness of the two surrogates in relation to different groups of test features. There were differences between study areas in terms of the effectiveness of surrogates for different test feature groups. Overall, the effectiveness of the surrogates was sensitive to all four factors. This indicates the need for caution in generalizing surrogacy tests.  相似文献   

7.
Summary A common approach to nature conservation is to identify and protect natural ‘assets’ such as ecosystems and threatened species. While such actions are essential, protection of assets will not be effective unless the ecological processes that sustain them are maintained. Here, we consider the role of ecological processes and the complementary perspective for conservation arising from an emphasis on process. Many kinds of ecological processes sustain biodiversity: including climatic processes, primary productivity, hydrological processes, formation of biophysical habitats, interactions between species, movements of organisms and natural disturbance regimes. Anthropogenic threats to conservation exert their influence by modifying or disrupting these processes. Such threats extend across tenures, they frequently occur offsite, they commonly induce non‐linear responses, changes may be irreversible and the full consequences may not be experienced for lengthy periods. While many managers acknowledge these considerations in principle, there is much scope for greater recognition of ecological processes in nature conservation and greater emphasis on long time‐frames and large spatial scales in conservation planning. Practical measures that promote ecological processes include: monitoring to determine the trajectory and rate of processes; incorporating surrogates for processes in conservation and restoration projects; specific interventions to manipulate and restore processes; and planning for the ecological future before options are foreclosed. The long‐term conservation of biodiversity and the well‐being of human society depend upon both the protection of natural assets and maintaining the integrity of the ecological processes that sustain them.  相似文献   

8.
基于不可替代性的青海省三江源地区保护区功能区划研究   总被引:3,自引:1,他引:2  
曲艺  王秀磊  栾晓峰  李迪强 《生态学报》2011,31(13):3609-3620
具有代表性、灵活性、综合性的保护区功能区划指标是决定区域划分合理与否的关键因素。不可替代性是近年来引入生物多样性保护规划的新概念,表达一个规划单元在实现整体保护目标中的重要性,能够反映生物多样性保护价值的空间分异规律,将其与人类活动干扰指数结合,可以在划分不同值域与功能分区之间建立联系。在系统保护规划框架下,首先根据三江源生物多样性特征确定了研究区域的指示物种和优先保护生态系统,然后结合物种生境特性,利用地理信息系统(GIS)技术进行了指示物种潜在分布范围预测,最后借助生物多样性保护规划软件(C-Plan)计算了三江源地区不可替代性指数,结合人类活动干扰进行了功能区划分,并对比了现有功能区划与新功能区划的贡献率。研究结果表明,不可替代性较高区域与原核心区空间分布基本一致(包括东部中铁、军功、麦秀森林灌丛区;西部索加、曲麻莱湖泊湿地区,高寒草甸区;北部扎陵湖、鄂陵湖、星星海湿地区;及南部玉树、囊谦森林灌丛区,当曲沼泽湿地区);在保护区总面积未增加条件下,基于不可替代性的新功能区划较原功能区划的保护贡献率及保护效率有显著提高,核心区保护贡献率由61.20%增长到71.21%,新核心区 缓冲区总贡献率由77.57%增长到92.45%,保护区整体贡献率由91.20%增长到95.40%;从保护对象被保护情况看,新功能区划与原功能区划均能完全涵盖所有保护对象,但新功能区所包含的满足保护目标的保护对象明显增多,原功能区核心区,核心区 缓冲区,核心区 缓冲区 实验区完全实现目标的保护对象分别占27.50%,47.50%和80%,新功能区分别为32.50%,77.50%和87.50%(新功能区划下,只有苔草草甸、冰川雪山、湖泊3种生态系统类型和盘羊、黑颈鹤两个动物物种未达到保护目标)。在本研究基础上,讨论了该研究的意义、方法评价及现实问题,并提出三江源自然保护区功能区划调整建议:1)结合实际情况,基于不可替代性和人类活动的功能区划对现功能区划进行适当调整以增加保护区的保护贡献率;2)对于缓冲区中保护价值较高、人类活动干扰又较强的区域应进行严格的管理,制定完善的管理策略,避免因人类活动引起生物多样性丧失;3)鉴于当地经济发展需求,可以考虑在本研究确定的实验区及其外围开展水电站与矿产开发项目,但必须考虑开发项目对周围水域、植被及居民的影响。以期为三江源自然保护区功能区划的调整及资源开发提供参考,对三江源生物多样性的保护具有重要意义。  相似文献   

9.
National-scale conservation assessments at an appropriate resolution   总被引:1,自引:0,他引:1  
Abstract.  Most national-scale conservation assessments are carried out at a resolution that is different from the actual size of protected areas in the study region. Coincidence between nature reserves and both hotspots (areas of high species richness) and complementary areas (sets of sites within which all species are represented) have been reported. However, the resolution (size of grid cells) of the species' distribution data upon which many of these studies are based is often close to an order of magnitude larger than the size of the reserves. Presumably, only a proportion of the species recorded in the coarse grid cells will actually be present on reserves. We use fine (2 × 2-km square grid cells) and coarse (10 × 10-km square grid cells) resolution data of national distributions for breeding birds throughout Great Britain, and presence data for avian species on Royal Society for the Protection of Birds (RSPB) nature reserves, to investigate the proportion of species in the local area (100 km2) that are actually present on reserves. RSPB reserves contain between 50% and 70% of species from the local area. These proportions are significantly higher than for randomly selected, non-reserve areas, indicating that RSPB reserves contain higher concentrations of bird species than the wider countryside. Furthermore, on RSPB reserves these proportions of threatened and non-threatened species are equal, whereas in non-reserve areas the proportions of non-threatened species are significantly higher than threatened species. Thus, reserves hold a higher proportion of threatened species than occurs in the wider countryside.  相似文献   

10.
Using the assessments of conservation status of flora and fauna, we discuss declining species in semi-natural field margins and stress the importance of these vanishing habitats. Seventy field margins in the diverse farmland of SW Poland were investigated with regard to their vascular plants, bryophytes and breeding birds. We checked the occurrence of threatened and conservation concern species, i.e. those listed in local, national or European threatened species lists, and birds with an unfavorable conservation status in Europe. Of a total of 673 species, 18 classified as threatened were recorded: 12 vascular plants (2.2 % of the total number of species), five bryophytes (5.6 %), and one bird species (2.0 %). Threatened plants occurred in 18.6 % of study plots, bryophytes in 20.0 % and birds in 12.9 %. Eleven bird species, noted in 95.7 % of study plots, had an unfavorable conservation status in Europe. Increasing volumes of trees and shrubs significantly increased the overall richness in each taxa. In percentage terms the occurrence of focal species in all three taxa tended to be higher in shrubby than in herbaceous and tree-lined margins. Our data demonstrate that field margins in Central European arable farmland regularly support rare and threatened species, and therefore deserve greater conservation efforts. Red lists along with alternative listing approaches can be employed to evaluate the biodiversity of fine-scale habitats, but their applicability depends on the taxonomic group and geographical scale of the lists, reflecting different conservation priorities.  相似文献   

11.
Successful conservation plans are not solely achieved by acquiring optimally designed reserves. Ongoing monitoring and management of the biodiversity in those reserves is an equally important, but often neglected or poorly executed, part of the conservation process. In this paper we address one of the first and most important steps in designing a monitoring program – deciding what to monitor. We present a strategy for prioritizing species for monitoring and management in multispecies conservation plans. We use existing assessments of threatened status, and the degree and spatial and temporal extent of known threats to link the prioritization of species to the overarching goals and objectives of the conservation plan. We consider both broad and localized spatial scales to capture the regional conservation context and the practicalities of local management and monitoring constraints. Spatial scales that are commensurate with available data are selected. We demonstrate the utility of this strategy through application to a set of 85 plants and animals in an established multispecies conservation plan in San Diego County, California, USA. We use the prioritization to identify the most prominent risk factors and the habitats associated with the most threats to species. The protocol highlighted priorities that had not previously been identified and were not necessarily intuitive without systematic application of the criteria; many high‐priority species have received no monitoring attention to date, and lower‐priority species have. We recommend that in the absence of clear focal species, monitoring threats in highly impacted habitats may be a way to circumvent the need to monitor all the targeted species.  相似文献   

12.
Deserts and arid regions are generally perceived as bare and rather homogeneous areas of low diversity. The Sahara is the largest warm desert in the world and together with the arid Sahel displays high topographical and climatic heterogeneity, and has experienced recent and strong climatic oscillations that have greatly shifted biodiversity distribution and community composition. The large size, remoteness and long‐term political instability of the Sahara‐Sahel, have limited knowledge on its biodiversity. However, over the last decade, there have been an increasing number of published scientific studies based on modern geomatic and molecular tools, and broad sampling of taxa of these regions. This review tracks trends in knowledge about biodiversity patterns, processes and threats across the Sahara‐Sahel, and anticipates needs for biodiversity research and conservation. Recent studies are changing completely the perception of regional biodiversity patterns. Instead of relatively low species diversity with distribution covering most of the region, studies now suggest a high rate of endemism and larger number of species, with much narrower and fragmented ranges, frequently limited to micro‐hotspots of biodiversity. Molecular‐based studies are also unravelling cryptic diversity associated with mountains, which together with recent distribution atlases, allows identifying integrative biogeographic patterns in biodiversity distribution. Mapping of multivariate environmental variation (at 1 km × 1 km resolution) of the region illustrates main biogeographical features of the Sahara‐Sahel and supports recently hypothesised dispersal corridors and refugia. Micro‐scale water‐features present mostly in mountains have been associated with local biodiversity hotspots. However, the distribution of available data on vertebrates highlights current knowledge gaps that still apply to a large proportion of the Sahara‐Sahel. Current research is providing insights into key evolutionary and ecological processes, including causes and timing of radiation and divergence for multiple taxa, and associating the onset of the Sahara with diversification processes for low‐mobility vertebrates. Examples of phylogeographic patterns are showing the importance of allopatric speciation in the Sahara‐Sahel, and this review presents a synthetic overview of the most commonly hypothesised diversification mechanisms. Studies are also stressing that biodiversity is threatened by increasing human activities in the region, including overhunting and natural resources prospection, and in the future by predicted global warming. A representation of areas of conflict, landmines, and natural resources extraction illustrates how human activities and regional insecurity are hampering biodiversity research and conservation. Although there are still numerous knowledge gaps for the optimised conservation of biodiversity in the region, a set of research priorities is provided to identify the framework data needed to support regional conservation planning.  相似文献   

13.
Understanding how natural selection generates and maintains adaptive genetic diversity in heterogeneous environments is key to predicting the evolutionary response of populations to rapid environmental change. Detecting selection in complex spatial environments remains challenging, especially for threatened species where the effects of strong genetic drift may overwhelm signatures of selection. We carried out a basinwide riverscape genomic analysis in the threatened southern pygmy perch (Nannoperca australis), an ecological specialist with low dispersal potential. High‐resolution environmental data and 5162 high‐quality filtered SNPs were used to clarify spatial population structure and to assess footprints of selection associated with a steep hydroclimatic gradient and with human disturbance across the naturally and anthropogenically fragmented Murray–Darling Basin (Australia). Our approach included FST outlier tests to define neutral loci, and a combination of spatially explicit genotype–environment association analyses to identify candidate adaptive loci while controlling for the effects of landscape structure and shared population history. We found low levels of genetic diversity and strong neutral population structure consistent with expectations based on spatial stream hierarchy and life history. In contrast, variables related to precipitation and temperature appeared as the most important environmental surrogates for putatively adaptive genetic variation at both regional and local scales. Human disturbance also influenced the variation in candidate loci for adaptation, but only at a local scale. Our study contributes to understanding of adaptive evolution along naturally and anthropogenically fragmented ecosystems. It also offers a tangible example of the potential contributions of landscape genomics for informing in situ and ex situ conservation management of biodiversity.  相似文献   

14.
15.
The increasing human impact on the earth's biosphere is inflicting changes at all spatial scales. As well as deterioration and fragmentation of natural biological systems, these changes also led to other, unprecedented effects and emergence of novel habitats. In boreal zone, intensive forest management has negatively impacted a multitude of deadwood‐associated species. This is especially alarming given the important role wood‐inhabiting fungi have in the natural decay processes. In the boreal zone, natural broad‐leaved‐dominated, herb‐rich forests are threatened habitats which have high wood‐inhabiting fungal species richness. Fungal diversity in other broadleaved forest habitat types is poorly known. Traditional wood pastures and man‐made afforested fields are novel habitats that could potentially be important for wood‐inhabiting fungi. This study compares species richness and fungal community composition across the aforementioned habitat types, based on data collected for wood‐inhabiting fungi occupying all deadwood diameter fractions. Corticioid and polyporoid fungi were surveyed from 67 130 deadwood particles in four natural herb‐rich forests, four birch‐dominated wood pastures, and four birch‐dominated afforested field sites in central Finland. As predicted, natural herb‐rich forests were the most species‐rich habitat. However, afforested fields also had considerably higher overall species richness than wood pastures. Many rare or rarely collected species were detected in each forest type. Finally, fungal community composition showed some divergence not only among the different habitat types, but also among deadwood diameter fractions. Synthesis and applications: In order to maintain biodiversity at both local and regional scales, conserving threatened natural habitat types and managing traditional landscapes is essential. Man‐made secondary woody habitats could provide the necessary resources and serve as surrogate habitats for many broadleaved deadwood‐associated species, and thus complement the existing conservation network of natural forests.  相似文献   

16.
Surrogacy analysis consists of determining a set of biotic or environmental parameters which can be rapidly assessed in the field and reliably used to prioritize places for biodiversity conservation. Whether adequate surrogate sets exist remains an open and relatively unexplored question though its solution is central to the aims of conservation biology. This paper analyses the surrogacy problem by prioritizing places using surrogate lists and comparing these results with those obtained by using more comprehensive species lists. More specifically, it explores (i) the possibility of using bird distributions, which are often easily available, as surrogates for species at risk (endangered and threatened species), which are presumed to be an important component of biodiversity; and (ii) the methodological question of how spatial scale influences surrogate success. The data set analysed, from southern Québec, is one of the most complete biotic data sets available at the regional scale. Contrary to some previous analyses, the results obtained suggest that the surrogacy problem is potentially solvable.  相似文献   

17.
18.
Aim We aimed to complete the first systematic assessment of extinction risk based on projected population declines derived from spatially explicit habitat projections for any taxonomic group at a regional scale, to use the outputs to ascertain the efficacy of an existing protected area network in covering species of conservation concern, and identify gaps therein. Location This study focused on Amazonia; an area of exceptional biodiversity, currently experiencing the highest absolute rate of forest loss globally but where the proportion of species assessed as ‘threatened’ on the International Union for the Conservation of Nature (IUCN) Red List in the region is below global averages. Methods For all forest‐dependent Amazonian bird species (814), we revised extinction risk estimates by combining data from a spatially explicit deforestation model with generation length estimates. By overlaying distribution maps for these revised threatened species, we identified crisis areas (areas of projected deforestation supporting the highest numbers of threatened species), refugia (areas projected to retain forest supporting the highest numbers of threatened species) and areas of high irreplaceability: short‐ and long‐term priorities for new protected areas (PAs). Results The number of species qualifying as threatened rose substantially from 24 (3%) to 64–92 (8–11%). Areas of particular concern are the crisis and highly irreplaceable areas within the ‘arc of deforestation’ in the southern Brazilian Amazon states of Rondônia, Mato Grosso and Pará. Main conclusions Through a novel application of the IUCN Red List criteria, we present a spatially accurate rendering of the extinction risks of Amazonian birds. Important areas in the Amazon are not secure. We identify priorities for expansion of the PAs network and key locations where protection should be enforced. We recommend a collaborative approach employing our methods to repeat this process for other taxonomic groups.  相似文献   

19.
Incomplete knowledge of biodiversity remains a stumbling block for conservation planning and even occurs within globally important Biodiversity Hotspots (BH). Although technical advances have boosted the power of molecular biodiversity assessments, the link between DNA sequences and species and the analytics to discriminate entities remain crucial. Here, we present an analysis of the first DNA barcode library for the freshwater fish fauna of the Mediterranean BH (526 spp.), with virtually complete species coverage (498 spp., 98% extant species). In order to build an identification system supporting conservation, we compared species determination by taxonomists to multiple clustering analyses of DNA barcodes for 3165 specimens. The congruence of barcode clusters with morphological determination was strongly dependent on the method of cluster delineation, but was highest with the general mixed Yule‐coalescent (GMYC) model‐based approach (83% of all species recovered as GMYC entity). Overall, genetic morphological discontinuities suggest the existence of up to 64 previously unrecognized candidate species. We found reduced identification accuracy when using the entire DNA‐barcode database, compared with analyses on databases for individual river catchments. This scale effect has important implications for barcoding assessments and suggests that fairly simple identification pipelines provide sufficient resolution in local applications. We calculated Evolutionarily Distinct and Globally Endangered scores in order to identify candidate species for conservation priority and argue that the evolutionary content of barcode data can be used to detect priority species for future IUCN assessments. We show that large‐scale barcoding inventories of complex biotas are feasible and contribute directly to the evaluation of conservation priorities.  相似文献   

20.
Restricted-Range Fishes and the Conservation of Brazilian Freshwaters   总被引:1,自引:0,他引:1  

Background

Freshwaters are the most threatened ecosystems on earth. Although recent assessments provide data on global priority regions for freshwater conservation, local scale priorities remain unknown. Refining the scale of global biodiversity assessments (both at terrestrial and freshwater realms) and translating these into conservation priorities on the ground remains a major challenge to biodiversity science, and depends directly on species occurrence data of high taxonomic and geographic resolution. Brazil harbors the richest freshwater ichthyofauna in the world, but knowledge on endemic areas and conservation in Brazilian rivers is still scarce.

Methodology/Principal Findings

Using data on environmental threats and revised species distribution data we detect and delineate 540 small watershed areas harboring 819 restricted-range fishes in Brazil. Many of these areas are already highly threatened, as 159 (29%) watersheds have lost more than 70% of their original vegetation cover, and only 141 (26%) show significant overlap with formally protected areas or indigenous lands. We detected 220 (40%) critical watersheds overlapping hydroelectric dams or showing both poor formal protection and widespread habitat loss; these sites harbor 344 endemic fish species that may face extinction if no conservation action is in place in the near future.

Conclusions/Significance

We provide the first analysis of site-scale conservation priorities in the richest freshwater ecosystems of the globe. Our results corroborate the hypothesis that freshwater biodiversity has been neglected in former conservation assessments. The study provides a simple and straightforward method for detecting freshwater priority areas based on endemism and threat, and represents a starting point for integrating freshwater and terrestrial conservation in representative and biogeographically consistent site-scale conservation strategies, that may be scaled-up following naturally linked drainage systems. Proper management (e. g. forestry code enforcement, landscape planning) and conservation (e. g. formal protection) of the 540 watersheds detected herein will be decisive in avoiding species extinction in the richest aquatic ecosystems on the planet.  相似文献   

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