首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
This study evaluates the effects of oil palm plantations on environmental heterogeneity and diversity (α and β) of aquatic Heteroptera (semi-aquatic and aquatic species) in Amazon streams. We assessed eight streams located in forested areas and 12 in oil palm plantations. As expected, oil palm areas had lower environmental heterogeneity, despite the presence of riparian vegetation. Heteropteran communities differed in forest and oil palm areas, however, only semi-aquatic bugs were affected by environmental variables. Streams in oil palm plantations had lower α-diversity and distinct community structures when compared to forest sites. Oil palm plantation did not affect the β-diversity of semi-aquatic bugs, however, there was increased β-diversity of aquatic bugs in these areas. These results reflect the impacts of environmental heterogeneity generated by plantations next to riparian vegetation, inducing local diversity loss. Effects on β-diversity differed among groups of Heteroptera, mainly due to the differences in the life histories of each group. Semi-aquatic bugs seem to undergo environmental filtering, while aquatic bugs can be structured by limiting similarity. Thus, the management and land conservation strategies adopted to preserve ecosystems within oil palm plantations were insufficient for the protection of aquatic heteropteran communities. In summary, such conservation policies should account for the particularities of different groups of the aquatic ecosystem; especially for aquatic fauna, which are usually overlooked in conservation policies for the Brazilian Amazon.  相似文献   

2.
Freshwater ecosystems are the most threatened ecosystems worldwide. Argentinian‐protected areas have been established mainly to protect vertebrates and plants in terrestrial ecosystems. In order to create a comprehensive biodiverse conservation plan, it is crucial to integrate both aquatic and terrestrial systems and to include macroinvertebrates. Here, we address this topic by proposing priority areas of conservation including invertebrates, aquatic ecosystems, and their connectivity and land uses. Location: Northwest of Argentina. We modeled the ecological niches of different taxa of macroinvertebrates such as Coleoptera, Ephemeroptera, Hemiptera, Megaloptera, Lepidoptera, Odonata, Plecoptera, Trichoptera, Acari, and Mollusca. Based on these models, we analyzed the contribution of currently established protected areas in the conservation of the aquatic biodiversity and we propose a spatial prioritization taking into account possible conflict regarding different land uses. Our analysis units were the real watersheds, to which were added longitudinal connectivity up and down the rivers. A total of 132 species were modeled in the priority area analyses. The analysis 1 showed that only an insignificant percentage of the macroinvertebrates distribution is within the protected areas in the North West of Argentina. The analyses 2 and 3 recovered similar values of protection for the macroinvertebrate species. The upper part of Bermejo, Salí‐Dulce, San Francisco, and the Upper part of Juramento basins were identified as priority areas of conservation. The aquatic ecosystems need special protection and 10% or even as much as 17% of land conservation is insufficient for species of macroinvertebrates. In turn the protected areas need to combine the aquatic and terrestrial systems and need to include macroinvertebrates as a key group to sustain the biodiversity. In many cases, the land uses are in conflict with the conservation of biodiversity; however, it is possible to apply the connectivity of the watersheds and create multiple‐use modules.  相似文献   

3.
Freshwater ecosystems provide goods and services of critical importance to human societies, yet they are among the most heavily altered ecosystems with an overproportional loss of biodiversity. Major threats to freshwater biodiversity include overexploitation, water pollution, fragmentation, destruction or degradation of habitat, and invasions by non-native species. Alterations of natural flow regimes by man-made dams, land-use changes, river impoundments, and water abstraction often have profound impacts on lotic communities. An understanding of the functional interactions and processes in freshwater ecosystems presents a major challenge for scientists, but is crucial for effective and sustainable restoration. Most conservation approaches to date have considered single species or single level strategies. In contrast, the concept of ‘Integrative Freshwater Ecology and Biodiversity Conservation’ (IFEBC) proposed herein addresses the interactions between abiotic and biotic factors on different levels of organization qualitatively and quantitatively. It consequently results in a more holistic understanding of biodiversity functioning and management. Core questions include modeling of the processes in aquatic key habitats and their functionality based on the identification and quantification of factors which control the spatial and temporal distribution of biodiversity and productivity in aquatic ecosystems. The context and importance of research into IFEBC is illustrated using case studies from three major areas of research: (i) aquatic habitat quality and restoration ecology, (ii) the genetic and evolutionary potential of aquatic species, and (iii) the detection of stress and toxic effects in aquatic ecosystems using biomarkers. In conclusion, our understanding of the functioning of aquatic ecosystems and conservation management can greatly benefit from the methodological combination of molecular and ecological tools.  相似文献   

4.
生物多样性保护优先区域代表了生物多样性富集区、典型生态系统与关键物种分布区, 对于生物多样性保护具有重要意义, 但优先区域内自然保护地覆盖率通常较低, 存在很大的保护空缺。苔藓植物作为生物多样性的一个重要组成部分, 在生态系统中发挥着重要作用, 但由于个体细小、分类鉴定困难等, 使得其多样性保护成为整个生物多样性保护中较为薄弱的一环。为了了解我国生物多样性保护优先区域苔藓植物多样性及受保护情况, 本文以黄山-怀玉山生物多样性保护优先区域内的石台县和青阳县为例, 通过系统的样线法调查优先区域内自然保护地内、外的苔藓植物多样性, 比较了其物种组成特点及相似性。结果表明, 该区域共有苔藓植物64科140属344种, 包括苔类植物27科40属106种、藓类植物37科100属238种, 其中有5种为濒危物种。自然保护地内有60科120属270种, 保护地外有46科90属185种, 保护地内、外苔藓植物科、属、种的Jaccard相似性系数分别为0.66、0.50和0.32, 表明自然保护地内、外物种组成差异很大。与石台县和青阳县苔藓植物历史数据相比, 本研究新增苔藓植物14科64属273种, 其中包括安徽省新记录2科9属96种, 而且有18种仅分布于自然保护地外。根据对该区域物种累积曲线及外推估计分析, 当采集足够充分时, 基于标本数的物种多样性预测值为485种, 基于样线数的预测值为563种, 说明石台县和青阳县的苔藓植物多样性仍存在被低估的可能。本研究结果一方面表明了自然保护地之外的苔藓植物在保护中有重要价值, 另一方面也反映了苔藓植物的野外就地保护存在空缺。建议在我国其他生物多样性保护优先区域开展类似的调查和研究, 以期为今后对苔藓植物的分布规律及保护研究提供翔实的基础数据。  相似文献   

5.
Conservation practices from the perspective of functional diversity (FD) and conservation prioritization need to account for the impacts of exotic species in freshwater ecosystems. This work first simulated the influence of exotic species on the values of FD in a schemed mechanistic model, and then a practical case study of conservation prioritization was performed in the Min River, the largest river in southeastern China, to discuss whether including exotic species alters prioritization. The mechanistic model revealed that exotic species significantly altered the expected FD if the number of exotic species occupied 2% of the community. Joint species distribution modelling indicated that the highest FD occurred in the west, northwest and north upstreams of the Min River. Values of FD in 64.69% of the basin decreased after the exotic species were removed from calculation. Conservation prioritization with the Zonation software proved that if first the habitats of exotic species were removed during prioritization, 62.75% of the highest prioritized areas were shifted, average species representation of the endemic species was improved and mean conservation efficiency was increased by 7.53%. Existence of exotic species will significantly alter the metrics of biodiversity and the solution for conservation prioritization, and negatively weighting exotic species in the scope of conservation prioritization is suggested to better protect endemic species. This work advocates a thorough estimate of the impacts of exotic species on FD and conservation prioritization, providing complementary evidence for conservation biology and valuable implications for local freshwater fish conservation.  相似文献   

6.
Aim Most approaches to conservation prioritization are focused on biodiversity features that are already threatened. While this is necessary in the face of accelerating anthropogenic threats, there have been calls to conserve large intact landscapes, often termed ‘wilderness’, to ensure the long‐term persistence of biodiversity. In this study, we examine the consequences of directing conservation expenditure using a threat‐based framework for wilderness conservation. Location The Australian continent. Methods We measured the degree of congruence between the extent of wilderness and the Australian protected area network in 2000 and 2006, which was established using a threat‐based systematic planning framework. We also assessed priority areas for future reserve acquisitions identified by the Australian government under the current framework. Results In 2000, 14% of Australia’s wilderness was under formal protection, while the protected area network covered only 8.5% of the continent, suggesting a historical bias towards wilderness protection. However, the expansion of the reserve system from 2000 to 2006 was biased towards non‐wilderness areas. Moreover, 90% of the wilderness that was protected over this period comprised areas not primarily designated for biodiversity conservation. We found a significant (P < 0.05) negative relationship between bioregions considered to be a priority for future reserve prioritization and the amount of wilderness they contain. Main conclusions While there is an urgent need to overcome past biases in reserve network design so as to better protect poorly represented species and habitats, prioritization approaches should not become so reactive as to ignore the role that large, intact landscapes play in conserving biodiversity, especially in a time of human‐induced climate change. This can be achieved by using current or future threats rather than past threats to prioritize areas, and by incorporating key ecological processes and costs of acquisition and management within the planning framework.  相似文献   

7.
外来生物入侵是继生境破坏后造成生物多样性丧失的第二大威胁因素, 已对入侵地的生态安全、经济和社会发展及人类健康等造成严重负面影响, 成为21世纪五大全球性环境问题之一。作为水产养殖、航运和水生宠物交易大国, 我国水生生态系统的生物入侵问题尤为严重。研究表明, 系统地构建并应用早期监测预警技术是防控水生生态系统生物入侵最有效的途径。和陆生生物相比, 水生生物群落的物种繁多、群落结构复杂、生物形体微小且在入侵初期群体规模极小、隐匿于水下、可用于物种鉴定的外部形态缺乏, 使得在水生生态系统中构建并应用早期监测和预警体系在技术层面更具挑战。随着高通量测序技术的快速发展, 环境DNA-宏条形码技术成为构建水生生态系统入侵生物早期监测与预警技术的首选。本文主要综述了基于环境DNA-宏条形码技术的水生生态系统入侵生物的早期监测与预警技术方法; 解析了环境DNA-宏条形码监测系统的应用现状、技术优势; 着重探讨了影响监测结果准确性的I型和II型错误及其产生原因, 并为避免两类错误提供了可行的优化/改进方案; 最后对该方法在水生入侵生物监测中的应用前景进行了展望。  相似文献   

8.
The complexity of nature conservation raises questions about biodiversity protection at the level of species as well as their spatial distribution between differently designated nature conservation areas. We have concentrated on comparison of the existing protected areas and recently established conservation initiative areas—Important Plant Areas. We have estimated how well these areas support the protection of two plant groups—bryophytes and vascular plants. We sought answers to the following questions: (a) are there any trends in the distribution of protected bryophyte and vascular plant species in the protected areas network, and (b) does the Important Plant Areas network promote better protection of bryophyte species compared with the existing protected areas network. Our results demonstrated that bryophytes need special care in nature conservation decisions to reach the reasonable conservation target. Important Plant Areas that were targeted to vascular plants have less importance in preserving bryophyte diversity than already existing conservation areas system. Conservation programs like IBA, IPA etc. have their specific tool and outcome to add conservation values to the existing protected areas system.  相似文献   

9.
综合三江平原湿地不同层次、不同维度的生物多样性特征,在系统保护规划方法(Systematic Conservation Planning,SCP)框架下,以集水区为规划单元,计算研究区域不可替代性指数,确定高保护价值网络体系,通过保护空缺分析对现有保护网络进行优化,并评估优化体系的有效性。结果表明:三江平原湿地高保护价值区域的分布呈现沿河流分布的特点;现有保护区中湖泊和目标物种的保护状态比较好;保护网络体系优化后,沼泽湿地在保护网络中的比重由22.88%重增加到50%以上;河流湿地由16.20%增加到33.92%;地下水资源在现有保护网络中的比重非常低,仅为2.01%,优化后保护网络中保护比重增加到12.05%,因此在今后的保护区规划中,应该重视对地下水资源的保护和管理。另外本研究结合生态脆弱性对高保护价值的空缺设计3个情景方案,并根据生态威胁的种类和强度提出各优先保护方案的保护建议,为保护管理决策提供依据。  相似文献   

10.
Wetlands are among the most threatened habitats and the species they support among the most endangered taxa. Measuring and monitoring wetland biodiversity is vital for conservation, restoration and management, and often relies on the use of surrogate taxa. Waterbirds are commonly used as flagships of biodiversity and are the subject of major conservation initiatives. Therefore, it is important to assess the extent to which waterbirds indicate the general biodiversity of wetlands and serve as surrogates.We explore the relationships between community composition and species richness of waterbirds and aquatic macroinvertebrates in 36 Ramsar wetlands in southern Spain to assess if waterbirds are good surrogates for other taxonomic groups. Specifically, we aimed to (i) test the congruence of patterns of species composition and richness among waterbirds and aquatic macroinvertebrates; and (ii) investigate which environmental variables are associated with the biodiversity patterns of waterbirds and macroinvertebrates, with the purpose of identifying key factors explaining potential discordance in these patterns.We found a limited concordance between assemblage patterns of both taxonomic groups that may be related to their contrasting responses to environmental gradients. Assemblages of waterbirds appear to be more affected by climate variables and water surface area, whereas conductivity was the most important factor influencing macroinvertebrate communities. Furthermore, we found a negligible or inverse relationship in their patterns of richness, with wetlands with higher waterbird species richness showing significantly lower richness of Hemiptera and macroinvertebrate families, and no significant relationship with Coleoptera. In addition, GLM models showed that, in general, different environmental variables are related with the richness patterns of the different taxonomic groups.Given the importance of the Ramsar convention for the conservation of an international network of wetlands, our findings underline the limited potential of waterbirds as aquatic biodiversity indicators in Mediterranean wetlands, and the need for caution when using waterbirds as flagships. An integrative analysis of different biological communities, using datasets from different taxonomic groups, is a necessary precursor for successful conservation policies and monitoring. Our results illustrate the need to create a diversified and complete network of protected sites able to conserve multiple components of wetland biodiversity.  相似文献   

11.
Large identifiable landscape units, such as ecoregions, are used to prioritize global and continental conservation efforts, particularly where biodiversity knowledge is inadequate. Setting biodiversity representation targets using coarse large‐scale biogeographic boundaries, can be inefficient and under‐representative. Even when using fine‐scale biodiversity data, representation deficiencies can occur through misalignment of target distributions with such prioritization frameworks. While this pattern has been recognized, quantitative approaches highlighting misalignments have been lacking, particularly for assemblages of mammal species. We tested the efficacy of Australia's bioregions as a spatial prioritization framework for representing mammal species, within protected areas, in New South Wales. We produced an approach based on mammal assemblages and assessed its performance in representing mammal distributions. Substantial spatial misalignment between New South Wales's bioregions and mammal assemblages was revealed, reflecting deficiencies in the representation of more than half of identified mammal assemblages. Using a systematic approach driven by fine‐scale mammalian data, we compared the efficacy of these two frameworks in securing mammalian representation within protected areas. Of the 61 species, 38 were better represented by the mammalian framework, with remaining species only marginally better represented when guided by bioregions. Overall, the rate at which mammal species were incorporated into the protected area network was higher (5.1% ± 0.6 sd) when guided by mammal assemblages. Guided by bioregions, systematic conservation planning of protected areas may be constrained in realizing its full potential in securing representation for all of Australia's biodiversity. Adapting the boundaries of prioritization frameworks by incorporating amassed information from a broad range of taxa should be of conservation significance.  相似文献   

12.
China is one of the countries in the world with therichest species biodiversityinfreshwater ecosystem.How-ever,duetothe rapid economic growthandthe continuingincrease of human disturbances and destructions of aquatichabitats,the biodiversity of freshwater ecosystemsis dras-tically declining.Waterbodies become more and more“deserted”of sensitive species.Water areas are reduced,fragmentized,and changed in their hydrodynamics(i.e.damming),causing changes in sedimentation and otherchanges.Forinstance,the area o...  相似文献   

13.
The biosphere is changing rapidly due to human endeavour. Because ecological communities underlie networks of interacting species, changes that directly affect some species can have indirect effects on others. Accurate tools to predict these direct and indirect effects are therefore required to guide conservation strategies. However, most extinction-risk studies only consider the direct effects of global change—such as predicting which species will breach their thermal limits under different warming scenarios—with predictions of trophic cascades and co-extinction risks remaining mostly speculative. To predict the potential indirect effects of primary extinctions, data describing community interactions and network modelling can estimate how extinctions cascade through communities. While theoretical studies have demonstrated the usefulness of models in predicting how communities react to threats like climate change, few have applied such methods to real-world communities. This gap partly reflects challenges in constructing trophic network models of real-world food webs, highlighting the need to develop approaches for quantifying co-extinction risk more accurately. We propose a framework for constructing ecological network models representing real-world food webs in terrestrial ecosystems and subjecting these models to co-extinction scenarios triggered by probable future environmental perturbations. Adopting our framework will improve estimates of how environmental perturbations affect whole ecological communities. Identifying species at risk of co-extinction (or those that might trigger co-extinctions) will also guide conservation interventions aiming to reduce the probability of co-extinction cascades and additional species losses.  相似文献   

14.
Mediterranean ecosystems have been recognized as a priority for biodiversity conservation due to their high levels of species richness and endemism. In South America, these environments are restricted to central Chile and represent a biodiversity hotspot. The study of saproxylic beetles in this area is an unexplored topic, despite the ecological role they play in these ecosystems and their potential usefulness for monitoring the degree of forest conservation. We investigated the diversity distribution of trophic guilds of saproxylic beetles in Chilean Mediterranean forests, to identify the main environmental variables that influence their distribution. We also analyzed seasonal dynamics as a key factor influencing insect communities and the effect of human disturbance on their diversity and composition. We identified characteristic species of perturbation degree as bioindicators for habitat monitoring. A total of 40 window traps were used to survey three Mediterranean forest types in the Río Clarillo National Reserve and the adjacent non-protected areas. We found that the diversity, abundance and composition of saproxylic beetles varied significantly spatiotemporally among the studied forest types and among perturbation degrees, showing different patterns depending on the trophic guild. Results indicated that conservation decisions should include the preservation of a larger range of different vegetation types and the nearby zones that have suffered low levels of disturbance or fragmentation and where actions promoting the presence of old native trees would have a significant conservation value.  相似文献   

15.
In recent decades, two of the main management tools used to stem biodiversity erosion have been biodiversity monitoring and the conservation of natural areas. However, socio-economic pressure means that it is not usually possible to preserve the entire landscape, and so the rational prioritisation of sites has become a crucial issue. In this context, and because floodplains are one of the most threatened ecosystems, we propose a statistical strategy for evaluating conservation value, and used it to prioritise 46 waterbodies in the Loire floodplain (France). We began by determining a synthetic conservation index of fish communities (Q) for each waterbody. This synthetic index includes a conservation status index, an origin index, a rarity index and a richness index. We divided the waterbodies into 6 clusters with distinct structures of the basic indices. One of these clusters, with high Q median value, indicated that 4 waterbodies are important for fish biodiversity conservation. Conversely, two clusters with low Q median values included 11 waterbodies where restoration is called for. The results picked out high connectivity levels and low abundance of aquatic vegetation as the two main environmental characteristics of waterbodies with high conservation value. In addition, assessing the biodiversity and conservation value of territories using our multi-index approach plus an a posteriori hierarchical classification methodology reveals two major interests: (i) a possible geographical extension and (ii) a multi-taxa adaptation.  相似文献   

16.
The biodiversity of freshwater systems is endangered, especially in Mediterranean semiarid areas such as the south east of the Iberian Peninsula, whose rich and endemic biota is threatened by the development of surrounding land-crop irrigation. For this reason, the prioritization of areas for biodiversity conservation is an urgent target. In this study we used data records of water beetles from a province of the southeast of Spain for assessing priority areas for freshwater biodiversity conservation. We compare the performance of various area-selection methods, ranging from scoring procedures to complementarity-based algorithms, which are based on different criteria such as richness, rarity and vulnerability. The complementarity approaches were more efficient than methods using scoring or richness and rarity hotspots for representing conservation targets in a given number of areas and for identifying the minimum set of areas containing all species at least once. Within these, the richness-based algorithm was more efficient than rarity-based algorithm. Crucial target habitats for aquatic biodiversity conservation in the area studied are streams at medium altitude, hypersaline streams, and endorreic and karstic complexes.  相似文献   

17.
Geist J  Kuehn R 《Molecular ecology》2008,17(4):997-1008
Biodiversity in fluvial ecosystems is under pressure as a consequence of their degradation. Conservation strategies for endangered freshwater molluscs and for salmonid fishes have been proposed but they are typically poorly integrated. Here, we examined for the first time the genetic structure of a critically endangered obligate mollusc invertebrate parasite, the freshwater pearl mussel ( Margaritifera margaritifera ), and its vertebrate host fish, the brown trout ( Salmo trutta m. fario ), in European headwater streams. We compared genetic differentiation and diversity with productivity and ecological habitat features of both species in nine different European streams from the drainage systems of the Danube, Elbe, Weser, Tuuloma, Kemijoki and Aulne. Genetic differentiation was more pronounced in pearl mussel than in brown trout, although the drainage-specific patterns were generally similar. Genetic diversity of host and parasite was negatively correlated. The most oligotrophic, postglacially colonized areas represented genetic diversity hotspots with high conservation priority for pearl mussels, whereas their host fish displayed low diversity in these areas. This pattern can be explained by differences in the ecological niches and in the life-history strategies of both species. These results question the effectiveness of single-species approaches in the conservation of genetic aquatic resources and suggest that genetic information from species with different life-history strategies, such as invertebrates and fish, should be considered simultaneously for geographical conservation prioritization in stream ecosystems.  相似文献   

18.
Mediterranean watercourses are among the most threatened ecosystems worldwide, being increasingly important to understand environmental drivers of biotic assemblages. Our aim was to provide a comprehensive picture of bryophyte communities in Mediterranean rivers and to determine the environmental factors that influence their distribution. We used floristic data collected for inter-calibration purposes under the European Water Framework Directive and River Habitat Survey, from 474 river reaches in six countries of the European Mediterranean basin. We analysed data through classification, ordination and environmental niche modelling techniques, and classified taxa according to biogeographic and aquatic habitat frameworks developed specifically for bryophytes. These analyses revealed four types of communities influenced by spatio-temporal precipitation patterns, altitude and water chemistry factors, most notably calcium and manganese. Community types are compositionally differentiated, although they share some core taxa and show an overall tendency to have several temperate and exclusively aquatic taxa despite the intermittent nature of water flow in highly seasonal Mediterranean rivers. The modelling approach can be improved at a more local scale when more bryological data and higher-resolution environmental information become available. Given future scenarios of climate change and human alteration of hydrological regimes, broader scales studies are needed to monitor shifts in bryophyte communities.  相似文献   

19.
20.
Rigorous and widely applicable indicators of biodiversity are needed to monitor the responses of ecosystems to global change and design effective conservation schemes. Among the potential indicators of biodiversity, those based on the functional traits of species and communities are interesting because they can be generalized to similar habitats and can be assessed by relatively rapid field assessment across eco-regions. Functional traits, however, have as yet been rarely considered in current common monitoring schemes. Moreover, standardized procedures of trait measurement and analyses have almost exclusively been developed for plants but different approaches have been used for different groups of organisms. Here we review approaches using functional traits as biodiversity indicators focussing not on plants as usual but particularly on animal groups that are commonly considered in different biodiversity monitoring schemes (benthic invertebrates, collembolans, above ground insects and birds). Further, we introduce a new framework based on functional traits indices and illustrate it using case studies where the traits of these organisms can help monitoring the response of biodiversity to different land use change drivers. We propose and test standard procedures to integrate different components of functional traits into biodiversity monitoring schemes across trophic levels and disciplines. We suggest that the development of indicators using functional traits could complement, rather than replace, the existent biodiversity monitoring. In this way, the comparison of the effect of land use changes on biodiversity is facilitated and is expected to positively influence conservation management practices.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号