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1.
Recent advances in molecular technology have revolutionized research on all aspects of the biology of organisms, including ciliates, and created unprecedented opportunities for pursuing a more integrative approach to investigations of biodiversity. However, this goal is complicated by large gaps and inconsistencies that still exist in the foundation of basic information about biodiversity of ciliates. The present paper reviews issues relating to the taxonomy of ciliates and presents specific recommendations for best practice in the observation and documentation of their biodiversity. This effort stems from a workshop that explored ways to implement six Grand Challenges proposed by the International Research Coordination Network for Biodiversity of Ciliates (IRCN‐BC). As part of its commitment to strengthening the knowledge base that supports research on biodiversity of ciliates, the IRCN‐BC proposes to populate The Ciliate Guide, an online database, with biodiversity‐related data and metadata to create a resource that will facilitate accurate taxonomic identifications and promote sharing of data.  相似文献   

2.
Much biodiversity data is collected worldwide, but it remains challenging to assemble the scattered knowledge for assessing biodiversity status and trends. The concept of Essential Biodiversity Variables (EBVs) was introduced to structure biodiversity monitoring globally, and to harmonize and standardize biodiversity data from disparate sources to capture a minimum set of critical variables required to study, report and manage biodiversity change. Here, we assess the challenges of a ‘Big Data’ approach to building global EBV data products across taxa and spatiotemporal scales, focusing on species distribution and abundance. The majority of currently available data on species distributions derives from incidentally reported observations or from surveys where presence‐only or presence–absence data are sampled repeatedly with standardized protocols. Most abundance data come from opportunistic population counts or from population time series using standardized protocols (e.g. repeated surveys of the same population from single or multiple sites). Enormous complexity exists in integrating these heterogeneous, multi‐source data sets across space, time, taxa and different sampling methods. Integration of such data into global EBV data products requires correcting biases introduced by imperfect detection and varying sampling effort, dealing with different spatial resolution and extents, harmonizing measurement units from different data sources or sampling methods, applying statistical tools and models for spatial inter‐ or extrapolation, and quantifying sources of uncertainty and errors in data and models. To support the development of EBVs by the Group on Earth Observations Biodiversity Observation Network (GEO BON), we identify 11 key workflow steps that will operationalize the process of building EBV data products within and across research infrastructures worldwide. These workflow steps take multiple sequential activities into account, including identification and aggregation of various raw data sources, data quality control, taxonomic name matching and statistical modelling of integrated data. We illustrate these steps with concrete examples from existing citizen science and professional monitoring projects, including eBird, the Tropical Ecology Assessment and Monitoring network, the Living Planet Index and the Baltic Sea zooplankton monitoring. The identified workflow steps are applicable to both terrestrial and aquatic systems and a broad range of spatial, temporal and taxonomic scales. They depend on clear, findable and accessible metadata, and we provide an overview of current data and metadata standards. Several challenges remain to be solved for building global EBV data products: (i) developing tools and models for combining heterogeneous, multi‐source data sets and filling data gaps in geographic, temporal and taxonomic coverage, (ii) integrating emerging methods and technologies for data collection such as citizen science, sensor networks, DNA‐based techniques and satellite remote sensing, (iii) solving major technical issues related to data product structure, data storage, execution of workflows and the production process/cycle as well as approaching technical interoperability among research infrastructures, (iv) allowing semantic interoperability by developing and adopting standards and tools for capturing consistent data and metadata, and (v) ensuring legal interoperability by endorsing open data or data that are free from restrictions on use, modification and sharing. Addressing these challenges is critical for biodiversity research and for assessing progress towards conservation policy targets and sustainable development goals.  相似文献   

3.
赵爽  宋博  侯笑云  丁圣彦  汤茜 《生态学报》2015,35(13):4398-4407
生物多样性是连接景观异质性与生态系统服务的桥梁。在区域尺度上,以指示类群代替地表节肢动物类群,可以有效的开展生物多样性的保护工作。但是,在黄河下游农业景观中,关于地表节肢动物指示类群的研究报道较少。以黄河下游农业景观中4种生境类型(农田、林地、树篱和沟渠)为研究样地,且在农田生境中划分不同尺度(尺度1,3.6 hm2、尺度2,14 hm2和尺度3,28 hm2),通过调查不同生境中地表节肢动物分布及其多样性,结合地表节肢动物优势类群的辨识,分析了优势类群和地表节肢动物多样性的相关性,确定了研究区内地表节肢动物多样性的指示类群。结果发现:研究区内地表节肢动物优势类群为膜翅目、鞘翅目和蜘蛛目。树篱和林地生境的地表节肢动物多样性指示类群是膜翅目,农田生境中地表节肢动物多样性指示类群是鞘翅目,沟渠生境中地表节肢动物多样性指示类群是蜘蛛目。农田生境中优势类群间无相关性(P0.05);林地、沟渠和树篱生境中鞘翅目与蜘蛛目之间存在显著正相关(P0.01);林地和沟渠生境中,鞘翅目与膜翅目之间存在正相关(P0.05)。在农田生境中优势类群之间的相关性存在尺度依赖性,随着空间尺度的增大,相关性有一定的增强。在尺度2和尺度3上膜翅目和鞘翅目均存在正相关(P0.05),并且随着尺度增加而呈上升趋势。研究表明,黄河下游农业景观中不同生境类型地表节肢动物多样性的指示类群差别较大,其中树篱和林地生境具有较高的相似性,而农田生境地表节肢动物优势类群相关性存在尺度依赖性。在黄河下游农业景观中,以优势类群多样性代替地表节肢动物类群的多样性,可以在条件不足、时间紧迫的情况下更加有效的开展生物多样性的保护工作。  相似文献   

4.
Aim Effective conservation of biodiversity relies on an unbiased knowledge of its distribution. Conservation priority assessments are typically based on the levels of species richness, endemism and threat. Areas identified as important receive the majority of conservation investments, often facilitating further research that results in more species discoveries. Here, we test whether there is circularity between funding and perceived biodiversity, which may reinforce the conservation status of areas already perceived to be important while other areas with less initial funding may remain overlooked. Location Eastern Arc Mountains, Tanzania. Methods We analysed time series data (1980–2007) of funding (n = 134 projects) and plant species records (n = 75,631) from a newly compiled database. Perceived plant diversity, over three decades, is regressed against funding and environmental factors, and variances decomposed in partial regressions. Cross‐correlations are used to assess whether perceived biodiversity drives funding or vice versa. Results Funding explained 65% of variation in perceived biodiversity patterns – six times more variation than accounted for by 34 candidate environmental factors. Cross‐correlation analysis showed that funding is likely to be driving conservation priorities and not vice versa. It was also apparent that investment itself may trigger further investments as a result of reduced start‐up costs for new projects in areas where infrastructure already exists. It is therefore difficult to establish whether funding, perceived biodiversity, or both drive further funding. However, in all cases, the results suggest that regional assessments of biodiversity conservation importance may be biased by investment. Funding effects might also confound studies on mechanisms of species richness patterns. Main conclusions Continued biodiversity loss commands urgent conservation action even if our knowledge of its whereabouts is incomplete; however, by concentrating inventory funds in areas already perceived as important in terms of biodiversity and/or where start‐up costs are lower, we risk losing other areas of underestimated or unknown value.  相似文献   

5.
Recent developments of molecular tools have revolutionized our knowledge of microbial biodiversity by allowing detailed exploration of its different facets and generating unprecedented amount of data. One key issue with such large datasets is the development of diversity measures that cope with different data outputs and allow comparison of biodiversity across different scales. Diversity has indeed three components: local (α), regional (γ) and the overall difference between local communities (β). Current measures of microbial diversity, derived from several approaches, provide complementary but different views. They only capture the β component of diversity, compare communities in a pairwise way, consider all species as equivalent or lack a mathematically explicit relationship among the α, β and γ components. We propose a unified quantitative framework based on the Rao quadratic entropy, to obtain an additive decomposition of diversity (γ = α + β), so the three components can be compared, and that integrate the relationship (phylogenetic or functional) among Microbial Diversity Units that compose a microbial community. We show how this framework is adapted to all types of molecular data, and we highlight crucial issues in microbial ecology that would benefit from this framework and propose ready‐to‐use R‐functions to easily set up our approach.  相似文献   

6.
Protection of regional biodiversity requires that priority for protection of individual areas be based on both the contribution the area can make to representing overall biodiversity and the degree to which the area, in the absence of action, is vulnerable to loss of its biodiversity. Attempts to apply these criteria together largely have been ad hoc. A solution to this problem is presented for environmental surrogate data, based on environmental diversity (ED). ED uses a standard ecological continuum model to link environmental pattern to species-level biodiversity, so that a set of areas can be characterized by its relative expected biodiversity. This allows explicit incorporation of estimates of area-vulnerability, interpreted as the relative probability that any member species will not persist, into biodiversity assessments. The contribution of a given area to regional expected biodiversity is influenced not only by its own vulnerability value, but also by the vulnerability of other areas. Increasing the degree of protection of any area (reducing its vulnerability) will increase expected biodiversity: however, expected regional biodiversity sometimes may be maximized when limited resources for protection are directed to an area with lower vulnerability rather than to one with higher vulnerability.The allocation of land uses in a region need not be viewed as an all-or-nothing assignment of protection. The effect of a particular management regime on the biodiversity of a given area can be equated with some consequent degree of vulnerability; viewed positively, a management regime that offers some degree of biodiversity protection can make a measurable contribution to the protection of the biodiversity of a region.  相似文献   

7.
Freshwater ecosystems are heavily impacted by multiple stressors, and a freshwater biodiversity crisis is underway. This realization has prompted calls to integrate global freshwater ecosystem data, including traditional taxonomic and newer types of data (e.g., eDNA, remote sensing), to more comprehensively assess change among systems, regions, and organism groups. We argue that data integration should be done, not only with the important purpose of filling gaps in spatial, temporal, and organismal representation, but also with a more ambitious goal: to study fundamental cross‐scale biological phenomena. Such knowledge is critical for discerning and projecting ecosystem functional dynamics, a realm of study where generalizations may be more tractable than those relying on taxonomic specificity. Integration could take us beyond cataloging biodiversity losses, and toward predicting ecosystem change more broadly. Fundamental biology questions should be central to integrative, interdisciplinary research on causal ecological mechanisms, combining traditional measures and more novel methods at the leading edge of the biological sciences. We propose a conceptual framework supporting this vision, identifying key questions and uncertainties associated with realizing this research potential. Our framework includes five interdisciplinary “complementarities.” First, research approaches may provide comparative complementarity when they offer separate realizations of the same focal phenomenon. Second, for translational complementarity, data from one research approach is used to translate that from another, facilitating new inferences. Thirdly, causal complementarity arises when combining approaches allows us to “fill in” cause–effect relationships. Fourth, contextual complementarity is realized when together research methodologies establish the wider ecological and spatiotemporal context within which focal biological responses occur. Finally, integration may allow us to cross inferential scales through scaling complementarity. Explicitly identifying the modes and purposes of integrating research approaches, and reaching across disciplines to establish appropriate collaboration will allow researchers to address major biological questions that are more than the sum of the parts.  相似文献   

8.
Science-based approaches to support the conservation of marine biodiversity have been developed in recent years. They include measures of ‘rarity’, ‘diversity’, ‘importance’, biological indicators of water ‘quality’ and measures of ‘sensitivity’. Identifying the sensitivity of species and biotopes, the main topic of this contribution, relies on accessing and interpreting available scientific data in a structured way and then making use of information technology to disseminate suitably presented information to decision makers. The Marine Life Information Network (MarLIN) has achieved that research for a range of environmentally critical species and biotopes over the past four years and has published the reviews on the MarLIN Web site (www.marlin.ac.uk). Now, by linking the sensitivity database and databases of survey information, sensitivity mapping approaches using GIS are being developed. The methods used to assess sensitivity are described and the approach is advocated for wider application in Europe.  相似文献   

9.
Niche division and abundance: an evolutionary perspective   总被引:1,自引:0,他引:1  
 In recent years, biodiversity has become an issue of broad academic interest, and its assessment and maintenance are now recognized as an important area of ecological research. While the concept of biodiversity encompasses, first and foremost, the total number of species co-occurring in a locality, it has increasingly been realized that information on the relative abundances of co-occurring species is also required for a better understanding of the patterns and dynamics of biodiversity. In many areas of ecological research, “abundance” constitutes a key variable that characterizes populations and communities. The relative abundances of species in natural communities reflect evolutionary and contemporary processes occurring on different spatiotemporal scales. The idea of niche apportionment has been developed to provide an integrated conceptual framework for the study of species abundance patterns in communities. This article reviews a number of important issues surrounding the concept of niche apportionment, including some aspects that have received very little or no consideration in previous ecological literature. The main emphasis here is on possible evolutionary implications and backgrounds. Further, as a universal factor which affects species abundance in one way or another, body size is highlighted and its relationship with abundance (“density–body-size relation”) is considered, referring in particular to a recent comprehensive analysis of freshwater benthic data. Consideration of this and other studies has led to the formulation of the biomass equivalence rule, that suggests the independence of the biomass measure of abundance from body size, which strengthens the logical basis of niche apportionment models. It is suggested that, compared with Hubbell's neutral theory of biodiversity, niche apportionment with the biomass equivalence rule represents a conceptually more sound and widely applicable approach to elucidating species abundance patterns. Received: February 4, 2002 / Accepted: October 25, 2002 Correspondence to:M. Tokeshi  相似文献   

10.
国家Ⅰ级重点保护极危植物藤枣研究进展   总被引:1,自引:0,他引:1  
国家Ⅰ级重点保护植物藤枣[Eleutharrhena macrocarpa(Diels)Forman]属防己科单种属植物,主要分布于云南南部地区。藤枣因其形态特征和分布式样在防己科植物中较为独特,具有重要的植物系统学和区系地理学研究价值。据相关文献记载,目前发现和记录的藤枣自然种群数量小于60株,种群处于极危状态,面临灭绝风险。国内外与藤枣相关的研究资料也相对匮乏。为及时拯救和关注这一濒危物种,该文在前贤研究的基础上,总结报道了藤枣的分类学简史、科学研究价值、自然种群数量、濒危状况、生物多样性保护地位、区系分布、模式标本认定等方面的最新研究进展,提出了近期的研究目标。期望能对藤枣的准确鉴定、精准调查和进一步深入研究提供基础信息和理论参考。  相似文献   

11.
Very little research has been conducted in the Himalayan and Karakorum Highlands of northern Pakistan on the aspects of biodiversity and conservation. The present research was carried out within the scope of the Pakistan–German Research Project, Culture Area Karakorum which aims to highlight the Problems and Prospects of High-Mountain Research in northern Pakistan. Naltar Valley, IUCN Management Category no. 4, located in the western Karakorums, is a remote area with difficult access. The current venture is two-fold; first, it describes the floral biodiversity of this remote area in northern Pakistan and second, discusses its exploitation by various entities with certain management implications to follow. Collection of species, their preservation and dialogue with the local, rural communities offered information on the plant biodiversity, providing the first extensive list of flora at the primary-valley level including their altitude range, habit and month of occurrence. In total, 153 plant species belonging to 38 families and 113 genera have been recorded after extensive field research in the area. Dominance has been observed for Asteraceae, Polygonaceae, Saxifragaceae and Rosaceae. Twenty-four plant species from Naltar emerged as ethnobotanically important for local medicinal uses and some commercial uses. Indeed, Thymus serpyllum, Gentiana tianshanica, Stellaria graminea, Geranium wallichianum and Capparris spinosa are the most important medicinal plants and their demand has increased, leading to over-exploitation. Cedrus deodara has completely disappeared from Naltar and Willow Salix sp. has almost been eradicated, except in the sub-alpine belts. The diversity of plant species within this remote area is very important for its obvious contribution to a sound mountain ecosystem. Prior to the present venture, not much was known about the floral aspects of this mountainous region of northern Pakistan. Many species are new additions to the plant list in this area. The species are distributed within the altitude range of 1,700–4,000 m and above, and are further explored for their ethnobotanical uses. It is recorded that some species are extensively used by the indigenous communities, some plant collectors from the lowlands and foreigners as well. Extensive grazing, uprooting of plants and soil-slope erosion intensify the environmental problems. A few species are further used for curing diseases through direct usage or marketing in the lowlands. Unfortunately, due to minor local conflicts, the area has been given low priority for its inclusion in the development and conservation programmes going on in other parts of these mountains. On the other hand, hospitable populations have a greater potential for the success of conservation and the wise usage of programmes. Concerted efforts are required to broaden our understanding of the dynamics of floral values as well as local concepts in this remote part of the world, and to check species decline. For sustainable use, in situ and ex situ conservation, controlled harvesting and aforestation may be the solution. Further extensive field conservation/management research is needed.  相似文献   

12.
An introduction to, and the Action StatementMicrobial Diversity 21 arising from, the joint IUBS/IUMS workshop on Biodiversity amongst microorganisms and its relevance held in Amsterdam on 7–8 September 1991 are presented. The workshop was held in support of the IUBS/SCOPE/UNESCO initiative on the importance of biodiversity in ecosystem function, namedDiversitas. The current state of knowledge on diverse aspects of the biodiversity of the various microorganism groups was reviewed by leading specialists, and a 14-point Action Plan was produced as a framework for future international initiatives in biodiversity research on microorganisms.  相似文献   

13.

Alkaline soda lakes are unique habitats found in specific geographic regions, usually with dry climate. The Carpathian Basin is one of those regions very important for habitat and biodiversity conservation in Europe, with natural soda lakes found in Austria, Hungary and Serbia. In comparison to other two countries from Central Europe, algal biodiversity studies of saline soda lakes in Serbia are scarce. Lake Velika Rusanda has the highest measured salinity of all saline lakes in the Carpathian Basin and there were no reports of its diatom species richness and diversity till now. We conducted 2-year investigation programme to study biodiversity and seasonal dynamics of diatoms in this lake. A total of 27 diatom taxa were found, almost all of them attached to reed and much less in benthos and plankton. Five new diatom species for Serbia were recorded, Craticula halopannonica, Navicymbula pusilla, Hantzschia weyprechtii, Nitzschia thermaloides and Navicula staffordiae. The last mentioned is new for Europe as well. Lake Velika Rusanda is inhabited mostly by alkaliphilous and halophilic diatoms. Since diatoms are used as bioindicators in soda lakes, our results will improve their further application in ecological status assessment of these fragile habitats in the Carpathian Basin.

  相似文献   

14.
Tropical Africa is home to an astonishing biodiversity occurring in a variety of ecosystems. Past climatic change and geological events have impacted the evolution and diversification of this biodiversity. During the last two decades, around 90 dated molecular phylogenies of different clades across animals and plants have been published leading to an increased understanding of the diversification and speciation processes generating tropical African biodiversity. In parallel, extended geological and palaeoclimatic records together with detailed numerical simulations have refined our understanding of past geological and climatic changes in Africa. To date, these important advances have not been reviewed within a common framework. Here, we critically review and synthesize African climate, tectonics and terrestrial biodiversity evolution throughout the Cenozoic to the mid-Pleistocene, drawing on recent advances in Earth and life sciences. We first review six major geo-climatic periods defining tropical African biodiversity diversification by synthesizing 89 dated molecular phylogeny studies. Two major geo-climatic factors impacting the diversification of the sub-Saharan biota are highlighted. First, Africa underwent numerous climatic fluctuations at ancient and more recent timescales, with tectonic, greenhouse gas, and orbital forcing stimulating diversification. Second, increased aridification since the Late Eocene led to important extinction events, but also provided unique diversification opportunities shaping the current tropical African biodiversity landscape. We then review diversification studies of tropical terrestrial animal and plant clades and discuss three major models of speciation: (i) geographic speciation via vicariance (allopatry); (ii) ecological speciation impacted by climate and geological changes, and (iii) genomic speciation via genome duplication. Geographic speciation has been the most widely documented to date and is a common speciation model across tropical Africa. We conclude with four important challenges faced by tropical African biodiversity research: (i) to increase knowledge by gathering basic and fundamental biodiversity information; (ii) to improve modelling of African geophysical evolution throughout the Cenozoic via better constraints and downscaling approaches; (iii) to increase the precision of phylogenetic reconstruction and molecular dating of tropical African clades by using next generation sequencing approaches together with better fossil calibrations; (iv) finally, as done here, to integrate data better from Earth and life sciences by focusing on the interdisciplinary study of the evolution of tropical African biodiversity in a wider geodiversity context.  相似文献   

15.
In Europe, ponds are an exceptionally numerous and widely distributed landscape feature forming a major part of the continental freshwater resource and contributing significantly to freshwater biodiversity conservation. This has been reflected by a growing scientific concern over the first few years of the twenty-first century and is evidenced by an increasing number of academic publications on pond related topics, particularly those relating to biodiversity. It is essential, however, that this expanding scientific knowledge is widely disseminated to those involved with pond management and is then rapidly translated into action. Inevitably, the task of transferring science to practice remains a significant challenge. As a first step towards meeting this challenge the European Pond Conservation Network (EPCN), at its biennial meeting in 2008 in Valencia (Spain), made this the main theme of the conference together with two special workshops further encouraging exchanges between scientists, practitioners and policy makers. The papers selected for this special issue of Hydrobiologia (from over 120 communications presented) are all from the conference. They represent a diverse collection of themes from across the continent and North Africa and present new and original insights into topics as wide ranging as: pond biodiversity; human disturbance; landscape ecology; ecological assessment and monitoring; practical management measures; ecological restoration; hydrology and climate change; invasive species and threatened species. In all cases, the papers demonstrate an overriding need for the development of a tight link between scientific knowledge and management. Furthermore, scientific advances have to be beneficial for on the ground management and, vitally, have to be disseminated, communicated and implemented into local, national and international policy. As such, national and international networks (such as the EPCN) have a central role to play and have to develop a robust information and communication strategy which will enable the dissemination of best practice materials and advice across the continent and beyond. The work contained in this volume represents a step in the right direction and will help to ensure that ponds remain a characteristic and highly visible feature of the European landscape in the twenty-first century. Guest editors: B. Oertli, R. Céréghino, A. Hull & R. Miracle Pond Conservation: From Science to Practice. 3rd Conference of the European Pond Conservation Network, Valencia, Spain, 14–16 May 2008  相似文献   

16.
In 2007 an unusual crayfish found in food markets in the capital of Madagascar was preliminarily identified as Procambarus ‘Marmorkrebs’: a new world taxa and the only decapod known to reproduce by parthenogenesis. We present information on the identity, distribution and ecology of this recent invader and attempt to evaluate the threat it poses to Madagascar’s biodiversity and to livelihoods. The species appears to be currently limited to the area close to Antananarivo, but is being sold alive on major transport routes. We present molecular evidence of its taxonomic relationships and confirm that the Procambarus present in Madagascar is indeed the parthenogenic taxa. We investigate its reproductive ecology and find Procambarus ‘Marmorkrebs’ to have an extremely high fecundity; more than six times that of the native crayfish Astacoides. The limited evidence we have suggests that this species poses a serious threat to freshwater biodiversity and that it is likely to damage human livelihoods (through its impact on fishing and possibly rice agriculture). More research is urgently needed but in the meantime action is needed to reduce the rate of spread before it is too late.  相似文献   

17.
近15年长江口海域海洋生物变化趋势及健康状况评价   总被引:2,自引:0,他引:2  
杨颖  刘鹏霞  周红宏  夏利花 《生态学报》2020,40(24):8892-8904
对近15年(2004-2018年)长江口海域海洋生物变化趋势进行分析,评价海洋生物健康状况,并对陆源污染物排放与海洋生物变化进行相关性分析。结果表明,(1)长江口海域海洋生物群落结构组成发生了一定变化,与20世纪90年代末相比,浮游植物种类数有所减少,浮游动物、底栖生物种类数有所增加。浮游植物以硅藻为主,但甲藻占比有所增加,2010年以来硅藻、甲藻群落结构进入新的平衡状态;浮游动物以节肢动物为主,主要类群桡足类占比有所下降;底栖生物种类数明显升高。(2)生物多样性总体水平一般,浮游植物多样性指数总体较低,第一优势种的优势度较高;浮游动物多样性指数和丰富度指数多年呈现下降趋势;底栖生物多样性水平一般,优势种渐趋单一。(3)海洋生物总体处于"不健康"状态,主要影响指标为浮游植物密度偏高,浮游动物密度偏低、生物量偏高,底栖动物密度偏高、生物量偏低。生态系统变化与陆源主要污染物排放、营养结构变化及水体富营养化均具有一定的相关性,其中无机氮(DIN)、石油类入海通量与生物健康指数呈显著负相关关系(P < 0.05),无机磷(DIP)与底栖生物生物量呈显著负相关关系。N/P与浮游植物丰度呈显著负相关,但与浮游植物均匀度和多样性指数呈显著正相关;Si/N与浮游植物多样性指数呈显著负相关。海域严重富营养化面积比例与硅藻甲藻种类数比值呈显著正相关关系。  相似文献   

18.
The use of indicator taxa as biodiversity surrogates has received widespread attention in conservation planning, but remains a highly contentious issue. Here we assess biodiversity surrogacy in the two most important biomes of tropical northeastern Brazil, Atlantic forest and Caatinga. We examine the extent to which species richness is correlated among taxonomic groups, and assess relationships between the richness of individual groups, and combinations of groups and total species richness. We introduce a new approach to dealing with autocorrelation between focal taxon richness and total species richness, using standardized data such that each taxon is given equal weight. Our Atlantic forest data covered seven taxa (bryophytes, pteridophytes, trees, ants, euglosine bees, birds, and mammals; total of 768 species) sampled from 12 sites; in Caatinga it was four taxa (trees, spiders, beetles and ants; total of 184 species) from 25 sites. Our results showed that: (1) in nearly all cases the species richnesses of individual taxa were significantly correlated with each other; (2) the species richnesses of most individual taxa were significantly correlated with total species richness in both biomes; (3) only two taxa were required for excellent (R 2 > 80%) surrogacy of total species richness in both biomes; and (4) the same two taxa (trees and ants) can provide reasonable (R 2 > 60%) surrogacy for total richness in these contrasting biomes. Our findings therefore suggest that the ‘shopping basket of taxa’ required for effective biodiversity surrogacy may not only need to be very small (two taxa), but may also be very limited in composition.  相似文献   

19.
Summary

The detrimental effects of conifer plantations on open ground habitats have been well catalogued and discussed, but the potential contribution of planted forests to the conservation of woodland biodiversity has not been quantified to the same extent. This quantification is needed urgently to help forest managers fulfil commitments to biodiversity enhancement as outlined in the UK Biodiversity Action Plan, the UK Forestry Standard and the UK Woodland Assurance Scheme (UKWAS). Results are presented from a five-year programme of research aimed at obtaining baseline information on biodiversity in planted forests and evaluating the contribution of planted forests to the conservation of native flora and fauna. Fifty-two plots were surveyed in total, covering a range of different tree crops (Scots pine Pinus sylvestris L., Sitka spruce Picea sitchensis (Bong.) Carr., Norway spruce Picea abies L. and Corsican pine Pinus nigra var maritima (Aitón) Melville) and stand ages (pre-thicket, mid-rotation, mature and over-mature) in three contrasting bioclimatic zones (upland, foothills and lowlands) throughout Britain. Additional plots were established in semi-natural woodland to allow comparisons between the biodiversity of plantations and native stands. Over 2000 species were recorded in total, including 45 Red Data Book species. Planted stands had similar or richer fungal and invertebrate communities to those of the native stands but poorer lichen and vascular plant communities. The latter were strongly affected by shading, dense, mid-rotation Sitka spruce stands having the lowest species counts. In contrast, these stands had a high diversity of mycorrhizal fungi, including a number of rare and threatened species normally associated with native pine wood. Bryophyte species-richness was related more to climate than woodland type, with the wetter upland spruce and native oak stands having the most diverse communities. Compared to the younger planted stands, over-mature planted stands had a higher proportion of species characteristic of semi-natural woodland stands. This related to greater structural diversity and higher deadwood volumes in the over-mature stands. It is concluded that conifer plantations make a positive contribution to biodiversity conservation in the UK and hence to the UK Biodiversity Action Plan. No single stand or crop type provides ‘optimal’ conditions for biodiversity, but the habitat value of plantations could be enhanced by increasing the area managed under alternative systems to clear-felling, such as ‘continuous cover’ and/or non-intervention natural reserves.  相似文献   

20.
The rise in research investigating fragmentation and its impact on primates and other taxa reflects the growing presence of fragmented landscapes themselves. Although numerous studies report the negative effects of fragmentation on biodiversity, it is difficult to generalize responses to fragmentation for specific taxonomic groups, such as non-human primates, when studies have not employed a definitive concept of fragmentation or fragments themselves. Madagascar's high degree of fragmentation, wealth of endemic taxa, and extensive history of ecological research provide the opportunity to compare fragmentation studies across similar contexts. We conducted a literature search of peer-reviewed articles on fragmentation in Madagascar to characterize its trends. A total of 70 articles, 46 of which concentrated on lemurs, tested the impacts of fragmentation on Malagasy taxa, while additional sources conducted research in one or more fragments without testing its effects (n = 112 total, 79 on lemurs). Studies on lemurs most frequently tested fragmentation's impacts on genetics and biodiversity metrics (n = 16 and 15 studies, respectively), although health, modeling, behavioral, and cross-disciplinary techniques were also reported. Responses to fragmentation were reported for 49 lemur species, with most studies concentrated in eastern Madagascar (87%). Although there was variation in the metrics reported in studies testing the effects of fragmentation on Malagasy species, the most common measures were fragment area, isolation, or comparison to a control site. Landscape-scale approaches and examination of fragmentation per se were rarely employed. Characterizing trends of fragmentation research in Madagascar emphasizes the challenges of documenting fragmentation's effects while highlighting the benefits of research within fragmented landscapes, particularly when combined with consideration for how the matrix within human-modified landscapes may impact primate populations.  相似文献   

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