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71.
We evaluated the effectiveness of line thinning, a new silvicultural technique, toward restoring diversity of Coleoptera in overstocked Cryptomeria japonica D. Don plantations in central Japan. We compared the abundance of some common Coleoptera families between line-thinned stands and adjacent unthinned stands in two plantations: low-elevation Sugi site (4 years since thinning) and high-elevation Kuchiotani site (6 years since thinning). Many bettle families comprising various functional groups such as plant feeders, wood borers, rotten wood feeders, root feeders, fungus feeders, dung feeders, and scavengers were more abundant in the line-thinned stands than in the unthinned stands. Furthermore, some important families were missing from the unthinned stands. There were strong positive relationships between Coleopteran abundance and understory vegetation. Our results suggest that line thinning may potentially increase biodiversity in overstocked C. japonica plantations by restoring important ecological processes such as food-web interactions (pollination, predation, herbivory, decomposition, parasitism, etc.), and habitat conditions.  相似文献   
72.
Changes in marine biodiversity through the Phanerozoic correlate much better with hyperbolic model (widely used in demography and macrosociology) than with exponential and logistic models (traditionally used in population biology and extensively applied to fossil biodiversity as well). The latter models imply that changes in diversity are guided by a first-order positive feedback (more ancestors, more descendants) and/or a negative feedback arising from resource limitation. Hyperbolic model implies a second-order positive feedback. The hyperbolic pattern of the world population growth arises from a second-order positive feedback between the population size and the rate of technological growth. The hyperbolic character of biodiversity growth can be similarly accounted for by a feedback between the diversity and community structure complexity. The similarity between the curves of biodiversity and human population probably comes from the fact that both are derived from the interference of the hyperbolic trend with cyclical and stochastic dynamics.  相似文献   
73.
74.
Species of the mitosporic filamentous fungal genus Trichoderma are prominent producers of both short (7-11 residues) and long (18-20 residues) peptaibols and peptaibiotics, which are thought to be involved in their interaction with other living systems. Numerous reviews are available regarding biodiversity, structure, and mode of action of these peptide derivatives, but little emphasis has been paid to the physiology and genetics of their formation. In this review article, we used the recent knowledge on biosynthesis and production of these components to speculate on some of the unknown points. We also highlight areas where further research is most urgently needed.  相似文献   
75.
The forest wealth of the Himalayan ranges is abundant with unique medicinal herbs, having tremendous economic importance. Latterly, these have adversely suffered at the hands of poachers and unlawful trade activities. The author cites the names of some of the rare species, in a bid to achieve their conservation through sensitization and participation of the masses, especially the tribals, in the greater interest of humanity.  相似文献   
76.
Protected areas such as nature reserves have been found to be effective in preventing habitat destruction and protecting ecosystems within their borders. Recent studies however found extensive loss of tropical forest habitat around protected areas, vastly contributing to increase the levels of ecological isolation. Using high-resolution satellite data we investigated the isolation trend occurring in the W-Arly-Pendjari (WAP) ecological complex in West Africa. A land-cover change analysis was performed for the period 1984–2002: savanna vegetation extension and loss were derived within the complex and in a 30 km peripheral buffer. Sample regions in the buffer were also analysed using selected spatial indicators to quantify temporal trends in habitat fragmentation. Implications for change in relative capacity to conserve biodiversity were discussed through the calculation of the species richness capacity (SRC). More than 14.5% of savanna habitat was lost in the WAP peripheral areas, while 0.3% was converted inside the complex. The degree of fragmentation of remnant savanna habitat has also drastically increased. Despite the effectiveness of the park conservation programme, we found through the SRC approach that the WAP complex is decreasing its potential capacity to conserve species richness. This process is mainly due to the rapid and extended agricultural expansion taking place around the complex. A better understanding of the ecological dynamics occurring in the peripheral regions of reserves and the consideration of development needs are key variables to achieve conservation goals in protected areas.  相似文献   
77.
土著知识在生物多样性保护和利用中的研究进展   总被引:3,自引:2,他引:1  
土著知识作为一种特定的知识形态,在保护生物多样性、促进资源可持续利用和社会协调发展等方面具有重要的作用,越来越受到社会各界尤其是学术界的重视。为了让大家更好地了解土著知识研究的状况,结合我们开展的工作,从国内外土著知识研究简史、土著知识研究代表性项目和单位及资助机构、土著知识项目实施产生的效果、土著知识研究利用的展望4个方面进行了综述。  相似文献   
78.
Desert soils harbor fungi that have survived under highly stressed conditions of high temperature and little available moisture. This study was designed to survey the communities of cultivable fungi in the desert soils of the Arabian Peninsula and to screen the fungi for the potentially valuable antioxidants (flavonoids, phenols, saponins, steroids, tannins, terpenoids, and alkaloids) and enzymes (cellulase, laccase, lipase, protease, amylase, and chitinase). Desert soil was sampled at 30 localities representing different areas of Saudi Arabia and studied for physico-chemical soil properties. Five types of soil texture (sand, loamy sand, sandy loam, silty loam, and sandy clay loam) were observed. A total of 25 saprotrophic species was identified molecularly from 68 isolates. Our survey revealed 13 culturable fungal species that have not been reported previously from Arabian desert soils and six more species not reported from Saudi Arabian desert soils. The most commonly recorded genera were Aspergillus (isolated from 20 localities) and Penicillium (6 localities). The measurements of biochemicals revealed that antioxidants were produced by 49 and enzymes by 52 isolates; only six isolates did not produce any biochemicals. The highest biochemical activity was observed for the isolates Fusarium brachygibbosum and A. phoenicis. Other active isolates were A. proliferans and P. chrysogenum. The same species, for instance, A. niger had isolates of both high and low biochemical activities. Principal component analysis gave a tentative indication of a relationship between the biochemical activity of fungi isolated from soil and soil texture variables namely the content of silt, clay and sand. However, any generalizable relation between soil properties and fungal biochemical activities cannot be suggested. Each fungal isolate is probable to produce several antioxidants and enzymes, as shown by the correlation within the compound groups. Desert soil warrants further research as a promising source of biochemicals.  相似文献   
79.
王伟  周越  田瑜  李俊生 《生物多样性》2022,30(10):22459-451
建立自然保护地是保护生物多样性最为重要的措施之一。总体来看, 自然保护地生物多样性保护研究主要围绕关键生态系统以及珍稀濒危物种等保护对象的状态以及变化两个层面进行, 并重点关注自然保护地数量与面积、保护了多少重要生态系统和物种、能否有效保护生物多样性等一系列科学问题。然而, 在自然保护地生物多样性保护研究方面, 还缺少针对上述研究领域的系统性综述。为此, 本文系统梳理了自然保护地空间布局及其与生物多样性分布的关系、自然保护地生物多样性变化及其保护成效等近20年来相关领域的研究进展。自然保护地的空间布局以及与生物多样性分布的关系主要围绕自然保护地与生物多样性在某一阶段的状态开展研究, 致力于探究自然保护地“保护多少” “代表性如何” “在哪儿保护”等一系列关键科学问题。同时, 自然保护地内的生物多样性会随着气候变化、人类活动以及自身演替等发生时空动态变化, 基于自然保护地生物多样性变化分析, 各国学者在全球尺度、国家尺度和单个自然保护地进行了大量的保护成效评估研究, 并逐渐发展出了自然保护地内外配对分析方法以提升保护成效评估的精度, 进而识别出不同自然保护地的主要影响因素。在此基础上, 本文进一步对自然保护地生物多样性保护研究提出了展望, 主要包括: (1)综合考虑自然保护地生物多样性状态和变化; (2)开展多目标协同的自然保护地空间优化布局; (3)强化自然保护地主要保护对象的识别、调查与监测; (4)提升自然保护地的质量和连通性; (5)探究自然保护地管理措施与保护成效的关联机制。本文可为“2020年后全球生物多样性框架”的制定与实施特别是在自然保护地体系建设与优化方面提供参考与借鉴。  相似文献   
80.
生物多样性的稳定维持关乎人类生存发展与地球健康。生物多样性核心监测指标(Essential Biodiversity Variables, EBVs)旨在结合地面调查与遥感技术, 为大尺度、长时间序列的生物多样性监测提供新的解决方案。然而, 目前学界仍然缺乏一套国家尺度标准化EBVs遥感监测产品数据集, 以进行生物多样性评估。本研究旨在对中国生物多样性核心监测指标遥感产品进行体系构建与思考, 首先综述了目前EBVs的遥感研究概况, 并根据EBVs研究文献的数量进行调研分析; 同时, 本文在已有遥感生物多样性产品优先标准的基础上, 添加了“可重复性”的新标准, 并据此构建了中国EBVs遥感产品体系与监测数据集的指标清单, 最终对中国EBVs遥感研究存在的问题进行思考与讨论。本研究可为中国的生物多样性遥感监测提供科学依据, 有望为中国生物多样性政策的制定提供支撑。  相似文献   
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