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Stimulated by the growing awareness of deforestation at all latitudes, the loss of species, declines in several fisheries, pollution, and other environmental threats, governments, citizen groups, academics, and indigenous peoples have been actively seeking ways to reverse current trends of impoverishment and achieve sustainable development. This paper considers the problems which confront managers of protected areas and proposes a six-point agenda for management based upon improved international policies, funding initiatives and other support mechanisms.  相似文献   

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我国作物种质资源保存研究与展望   总被引:3,自引:0,他引:3  
我国于1984年1986年在北京建成两座国家种质库,90年代初又在青海建立一座复份库,形成了国家库中,长期配套和异地结合的种质资源保存体系。截止1993年底,国家库保存种质资源达27万余份,到1995年保存总数将达到30余万份。与种子入库时,在国家库的管理,种子质量检测,种子干燥以及低温保存技术研究等方面取得一定进展,今后将继续扩大种质贮存、加强贮存种子生活力跟踪监测,无破坏性检测技术,贮存生理和  相似文献   

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In situ conservation of crop wild relatives: status and trends   总被引:2,自引:0,他引:2  
Recognized as a priority three decades ago, in situ conservation of crop wild relatives has developed theoretical and methodological focus and achieved significant on-the-ground progress in the last 10 years, most notably under the impetus of the plant genetic resources community. Literature and Internet searches and interviews with experts were undertaken as a basis for reviewing the current status and trends of this effort worldwide. Country-by-country summaries on in situ crop wild relatives conservation activities are presented, and recommendations are made for future action. Principal recommendations include flagging of appropriate taxa as crop wild relatives in botanical and conservation databases, undertaking gap analyses to locate crop wild relatives hotspots, and enhancing cooperation between the plant genetic resources and plant conservation communities.  相似文献   

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1. This paper is a synthesis of a special issue on groundwater biodiversity with a focus on obligate subterranean species, the stygobionts. The series of papers constitutes a great leap forward in assessing and understanding biodiversity patterns because of the use of large quantitative data sets obtained over a broad geographic scale. They also represent a conceptual shift, away from a purely taxonomic and phylogenetic focus to the analysis of whole groundwater assemblages.
2. The general patterns emerging for groundwater fauna are: very high levels of endemism, low local diversity relative to regional diversity, a limited number of lineages, occurrence of many relicts, and truncated food webs with very few predators.
3. β-Diversity is at least as important as α-diversity in determining total richness at different scales (aquifer, basin and region) and overall taxa richness increases across spatial scales.
4. Advances in understanding groundwater biodiversity patterns further include identification of several important factors related to geology and hydrology that determine the composition of European stygobiotic assemblages.
5. Important challenges for future research include improving sampling strategies, filling gaps in sampling coverage, intensifying research on theoretical and statistical models, and including functional and genetic diversity components in biodiversity assessments.
6. Strategies are proposed for protecting groundwater biodiversity and an argument is made to integrate biodiversity in groundwater management. Applying principles such as complementarity and flexibility for groundwater biodiversity conservation is a major step toward delineating a reserve network that maximise species representation at the European scale.  相似文献   

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中国银鱼的多样性及其保护对策   总被引:18,自引:2,他引:18  
中国是世界银鱼(银鱼科Salangidae的简称)的起源地和主要分布区,在中国东部近海和各大水系的河口共分布有世界17种银鱼中的15种,其中特有种6种。银鱼营养价值和经济价值均很高,是重要的经济鱼类。银鱼生活周期短、世代离散、生殖力和定居能力强。作为典型的r对策者,银鱼对环境变化敏感且反应迅速,种群消长快,在漫长的进化过程中形成了其种间食性、生长和繁殖等生物学和生态学特征的丰富的多样性。然而我国的银鱼天然资源却因围湖造田、过度捕捞、环境污染和生境破碎化等多种因素的影响而持续衰退,各种银鱼的天然资源都不同程度地下降,物种分布范围显著缩小,个别物种渐危。本文在综述我国银鱼生物学、生态学和生物多样性研究的基础上,分析了我国银鱼研究及其物种多样性和种质资源保护工作中所面临的问题;呼吁审视银鱼移植增殖的生态效应,加强银鱼的基本生态学研究和生物多样性保护,并提出我国银鱼资源保护和可持续利用的对策。  相似文献   

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Insectivorous bats are integral components of terrestrial ecosystems. Despite this, a growing number of factors causing world‐wide declines in bat populations have been identified. Relatively abundant species are important for bat conservation because of their role in ecosystems and the research opportunities they offer. In addition, species that have been well‐studied present unique opportunities to synthesize information and highlight important areas of focus for conservation and research. This paper focuses on a well‐studied abundant bat, Eptesicus fuscus. I review the relevant literature on habitat use, diet and roost selection by E. fuscus in North America, and highlight important areas of conservation and research for this species, including the effects of roost disturbance, control of economically important insect pests, exposure to pesticides, long‐term monitoring of populations, and the potential consequences of expanding populations. These issues have broad implications for other species and can be used to focus future research and conservation efforts.  相似文献   

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本研究选取黄麻属(Corchorus)2个栽培品种及其4个野生类型和3个野生近缘种为材料,采用常规根尖压片法对黄麻属供试材料的染色体数目和核型进行研究。结果表明:染色体数目均为2n=14。核型公式分别为:宽叶长果(长果黄麻栽培种)2n=2x=14=14m(4SAT);南阳野生长果(长果黄麻野生类型)2n=2x=14=14m(2SAT);坦桑尼亚野生长果(长果黄麻野生类型)2n=2x=14=2M+12m;闽麻5号(圆果黄麻栽培种)2n=2x=14=12m+2sm;爱店野生圆果(圆果黄麻野生类型)2n=2x=14=14m ;廉江野生圆果(圆果黄麻野生类型) 2n=2x=14=4M+10m;假黄麻(黄麻属野生近缘种)2n=2x=14=2M+12m;假长果(黄麻属野生近缘种)2n=2x=14=2M+12m;甜麻(黄麻属野生近缘种)2n=2x=14=14m。其中除了宽叶长果核型分类为1B外,其他的都为1A型。本文还讨论了黄麻野生近缘种甜麻的分类学地位。  相似文献   

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We describe or redescribe species of Hypocrea/Trichoderma (Ascomycetes, Hypocreales) having hyaline ascospores and pachybasium-like conidiophores. Teleomorphs are reported for Trichoderma minutisporum (Hypocrea minutispora sp. nov.) and T. polysporum (H. pachybasioides). Hypocrea pilulifera/T. piluliferum is redescribed. Trichoderma croceum is synonymized with T. polysporum. The new species H. parapilulifera, H. stellata and H. lacuwombatensis are described. All of these species fall within the morphological concept of Trichoderma sect. Pachybasium and within the phylogenetic group pachybasium B5 of Kullnig-Gradinger et al (2002). Parsimony analysis of nucleotide sequences from three unlinked loci-ITS1 and 2, endochitinase (ech42) and translation elongation factor 1-alpha (tef1)-detects two distinct phylogenetic lineages within the group pachybasium B5. One comprises H. pachybasioides/T. polysporum, H. pilulifera/T. piluliferum, H. parapilulifera and H. stellata; this group, the "polysporum" lineage, is characterized by having conidia that are white in mass and is the only lineage within Hypocrea characterized by such conidia. The second group includes the green conidial T. minutisporum and H. lacuwombatensis. The partition homogeneity test reveals significant recombination within the "polysporum" lineage but not within the "minutisporum" lineage.  相似文献   

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As defaunation spreads through the world, there is an urgent need for restoring ecological interactions, thus assuring ecosystem processes. Here, we define the new concept of credit of ecological interactions, as the number of interactions that can be restored in a focal area by species colonization or reintroduction. We also define rewiring time, as the time span until all the links that build the credit of ecological interactions of a focal area have become functional again. We expect that the credit will be gradually cashed following refaunation in rates that are proportional to (1) the abundance of the reintroduced species (that is expected to increase in time since release), (2) the abundance of the local species that interact with them, and (3) the traits of reintroduced species. We illustrated this approach using a theoretical model and an empirical case study where the credit of ecological interactions was estimated. This new conceptual framework is useful for setting reintroduction priorities and for evaluating the success of conservation initiatives that aim to restore ecosystem services.  相似文献   

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罗茂芳  杨明  马克平 《广西植物》2023,43(8):1350-1355
在中国作为主席国的引领下,联合国《生物多样性公约》(以下简称《公约》)第十五次缔约方大会(以下简称COP15)第二阶段会议通过了62项决定,特别是达成了以变革理论为基础的《昆明-蒙特利尔全球生物多样性框架》(以下简称《昆蒙框架》),为全球生物多样性治理擘画了新的蓝图。该文就《昆蒙框架》的三个核心目标——保护地“3030目标”、资源调动、遗传资源数字序列信息进行解读,对保障《昆蒙框架》落地的相关决议进行简要介绍,并就我国未来的保护行动提出了相关建议:(1)加强生物多样性保护的主流化;(2)进一步制定详细的保护计划,明确保护区域的范围、目的和管理措施,并落实实施计划的责任部门和具体措施;(3)根据框架目标的监测要求,制定可操作的指标体系和监测计划;(4)继续加强生物多样性保护的意识和教育,提高公众对生物多样性保护的认识和重视程度,促进全社会的可持续生产和可持续消费;(5)大力推进国际合作,在更大尺度上探索和促进基于自然的解决方案,寻找对自然产生正面、积极效果的经济和社会发展路径。  相似文献   

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Factors influencing the fate and impact of hybrids between crop plants and their related species operate from the early zygote, through to plant establishment in different habitats, to their ability to form self-sustaining populations. Many of the classes of genes being introduced by modern methods of genetic modification are similar to those manipulated by conventional plant breeding. In assessing the impact of transgenes in hybrids between crops and related species, therefore, it is important to be informed about the consequences of hybridization between conventionally bred varieties and their relatives. Some transgenes will have novel effects (e.g. production of pharmaceutical substances or certain fatty acids) on plants, and are likely to need specific assessment studies to determine their impact on hybrids. This will be particularly important if there is the possibility of these transgenes becoming established in wild populations. Some recommendations for further research are outlined.  相似文献   

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The diversity of marine communities is in striking contrast with the diversity of terrestrial communities. In all oceans, species richness is low in tropical areas and high at latitudes between 20 and 40°. While species richness is a primary metric used in conservation and management strategies, it is important to take into account the complex phylogenetic patterns of species compositions within communities. We measured the phylogenetic skew and diversity of shark communities throughout the world. We found that shark communities in tropical seas were highly phylogenetically skewed, whereas temperate sea communities had phylogenetically diversified species compositions. Interestingly, although geographically distant from one another, tropical sea communities were all highly skewed toward requiem sharks (Carcharhinidae), hammerhead sharks (Sphyrnidae), and whale sharks (Rhincodon typus). Worldwide, the greatest phylogenetic evenness in terms of clades was found in the North Sea and coastal regions of countries in temperate zones, such as the United Kingdom, Ireland, southern Australia, and Chile. This study is the first to examine patterns of phylogenetic diversity of shark communities on a global scale. Our findings suggest that when establishing conservation activities, it is important to take full account of phylogenetic patterns of species composition and not solely use species richness as a target. Protecting areas of high phylogenetic diversity in sharks, which were identified in this study, could form a broader strategy for protecting other threatened marine species.  相似文献   

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As an introduction to the Special Issue on the restoration of threatened plant species and their habitats,this editorial shows how the various papers in the issue address the range of in situ interventions involved in species population management and restoration of their habitat, together with examples of case studies implementing these actions. It stresses the need for integrating these various interventions.It highlights the importance of protected areas in providing a degree of protection for threatened species but also the need to complement this with actions at the species level to ensure the effective conservation and long term persistence of these species. It emphasizes that ecological restoration is a complement to, not a substitute for conservation, and that the balance of effort and allocation of resources between them is a key issue.  相似文献   

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Assessing the impact of hybrids between transgenic plants and nontarget wild species involves answering several questions such as: (i) what are the hybridization and introgression rates; (ii) what is the behaviour of a transgene in a wild population; and (iii) what will be the consequences of the expression of a transgene in a wild population? These issues are discussed using results from experiments on oilseed rape and wild related Brassiceae. Evidence is given of large variations in the estimates of cross-fertilization probabilities. The first stage of introgression into wild populations is demonstrated to occur spontaneously through back-crossing. Population analysis may also be valuable to detect traces of past introgression. Data from the literature on weed biology, and especially herbicide resistance, are used to illustrate the behaviour of a new gene in weed populations. The need for computer models simulating the introgression process is stressed.  相似文献   

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Jeff R. Troy  Clark D. Jones 《Ibis》2023,165(1):340-351
The Ivory-billed Woodpecker Campephilus principalis was considered extinct by many until, in 2005, researchers announced its rediscovery in continental North America and released video evidence obtained from the state of Arkansas. This claim garnered worldwide media attention and sparked renewed interest in searching for and conserving the bird. Audio recordings from the same region, including sounds closely resembling the territorial double raps of Campephilus woodpeckers, were also released. Both the video and audio evidence, however, were challenged in several journal articles, though these critiques did not receive as much attention. We estimated that over 578 000 h were collectively spent searching for the species across the southeastern USA from 2004 to 2021, but these efforts failed to yield indisputable proof of the species' persistence. More than US$ 20.3 million in federal and state government funding was spent on the bird from 2005 to 2013, a sharp increase in expenditures from the years before the rediscovery announcement. Regardless of whether or not it was a reallocation of funds from other taxa, this money, along with other associated resources (e.g. time and human effort), would have undoubtedly benefited other underfunded threatened and endangered taxa had it not been spent on the woodpecker. Given the published criticisms and counterevidence, as well as the lack of definitive proof that the species still exists, it appears that this endeavour was driven largely by the narrative of rediscovery advanced by prominent researchers in ornithology, rather than the actual evidence, and that this probably helped to perpetuate the use of poor-quality evidence in subsequent claims of the species' persistence. In 2021, the US Fish and Wildlife Service proposed an extinction declaration for the Ivory-billed Woodpecker. Based on available information, this decision seems logical, and would close this chapter on one of the biggest losses to North American avifauna in modern history.  相似文献   

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