共查询到19条相似文献,搜索用时 93 毫秒
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江玉林 《国外畜牧学(草原与牧草)》1999,(1):4-9
介绍了生物多样性概念及与生态系统结构和功能的关系,分析了生物多样性减少的主要人为因素与途径,提出了生物多样性研究的主要内容及利用遥感和地理信息系统(GIS)技术进行生物多样性保护的方案。 相似文献
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生物多样性保护的基础工作——生物编目 总被引:2,自引:0,他引:2
生物编目(biological inventory)主要是调查和收集物种、生态系统以及遗传资源的信息,并建立数据库。数据库能够提供生物多样性和生物资源管理所必需的数据,利用这些数据可以建立生物多样性信息系统,信息系统的目的主要在于利用系统中各种数据库建立有关生物多样性监测和评估模型、生物多样性空间分布及其形成机制模型、关键物种长期种群动态模型、系 相似文献
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生物多样性及生物多样性保护 总被引:6,自引:1,他引:5
生物多样性已成为当今研究世界环境问题的重要课题之一,受到世界各国的普遍重视。从生物多样性的概念出发,对目前国内外生物多样性研究的几个热点作了概括,分析了生物多样性丧失的原因,提出了生物多样性保护的措施和建议。 相似文献
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草地生态系统是受人类活动影响最大的陆地生态系统之一,其功能的发挥过程就是系统不断经受人类生产活动干扰的过程。人类的干扰活动可直接或间接地改变生物群落间的相互关系,导致自然生境的根本丧失,从而对生物多样性和系统功能产生重大影响。但适度的干扰有利于生物多样性和系统稳定性的增加。因此,在对草地生态系统实施管理利用措施时,应掌握干扰的"适度"问题。 相似文献
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呼伦贝尔草地风蚀沙化植被生物多样性研究 总被引:14,自引:1,他引:14
对呼伦贝尔草地沙化过程中不同演替阶段植被物种组成和生物多样性研究结果表明:草地沙化、灌丛化明显,群落结构趋于简单化;群落α多样性急剧下降,其中,物种丰富度、多样性、均匀性严重沙化草地分别比潜在沙化草地减少59.4%、54.0%和31.4%,而生态优势度增加44.9%,说明草地沙化后群落物种数减少,优势种更加突出.四类沙化草地群落相似性与未沙化草地比较,相似系数分别为0.8649、0.6486、0.2593和0.1200,而四类沙化草地β多样性变化均呈明显增大趋势,其中严重沙化草地比潜在沙化草地高14.6倍,说明β多样性增大,群落相似性降低,生境异质性加大,预示草地沙化程度严重. 相似文献
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In order to elucidate the taxonomic status of the melanistic, girdled lizard, Cordylus cordylus niger, occurring in the Cape Peninsula and the Saldanha Bay area, South Africa, character variation among populations of the C. cordylus complex in the section of the Cape Province south of 32°3C latitude and west of 19°30' longitude was analysed. Variation for 92 external morphological characters at 54 localities was determined. Distinct patterns of interlocality variation were observed in only eight characters, but interestingly, these patterns were concordant in all eight cases. The observed patterns are interpreted as indicating that three phenotypic forms of the nominate species occur in the south-western Cape, namely a coastal melanistic form (= C. c. niger), occurring in insular and peninsular situations along the coast; a montane melanistic form occurring at relatively high altitudes along the western section of the Cape Fold Mountains; and the typical form (= C. c. cordylus), occurring commonly along the coastal lowlands, but also further inland at some places. 相似文献
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Ecology of Rhodococcus equi 总被引:7,自引:0,他引:7
A selective broth enrichment technique was used to study the distribution of Rhodococcus equi in soil and grazing animals. Rhodococcus equi was isolated from 54% of soils examined and from the gut contents, rectal faeces and dung of all grazing herbivorous species examined. Rhodococcus equi was not isolated from the faeces or dung of penned animals which did not have access to grazing. The isolation rate from dung was much higher than from other samples and this was found to be due to the ability of R. equi to multiply more readily in dung. Delayed hypersensitivity tests were carried out on horses, sheep and cattle, but only horses reacted significantly. The physiological characteristics of R. equi and the nature of its distribution in the environment suggested that R. equi is a soil organism. 相似文献
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