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生物多样性指地球上丰富多样、千差万别的植物、动物和微生物的种类及它们所构成的复杂的生态系统,是一个涉及基因、物种和生态系统的概述语。生物多样性可分为遗传多样性、物种多样性和生态系统多样性,是地球上最珍贵的资源,是人类赖以生存和发展的自然基础——基本食物、药物和工业原料的主要来源。当今世界面临的资源、环境和人口等重大问题的产生和解决与生物多样性有着直接密切的联系。人类活动已使大量生物物种在还没有被人们发现其利用价值之前就已经消失,这是人类长久生存和发展的莫大损失。 人类为了生存和发展,经常不顾后果地开发利用自然资源,从而破坏了生态平衡、产生了各种各样的污染问题。在过去的4亿年当中,平均每27年才有一个高等植物物种消亡,而联合 相似文献
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Asokkumar Bhattacharya Santosh Kumar Sarkar 《Ambio-人类环境杂志》2003,32(1):70-75
引言 生物多样性是生态系统结构和功能的一项基本属性.它是一连串概念[1],包括从基因学和分子生物学到群落结构和生境的异质性等多个相互联系的方面.生态学家利用多个指数量测生物多样性,所有这些指数或多或少直接地将种的数量与丰度和/或数量优势相联系[3]. 相似文献
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1.介绍如何衡量环境产品的价值是生态学家和经济学家们目前面临的一个问题,对环境产品的毁坏(与人类企业规模永无止境的增长有关)造成了巨大的外在影响。这种环境产品之一的主要例子就是生物多样性——与人类共享地球的植物、动物和微生物的不同数量和种类在遗传学上的多样性,以及由它们互相作用构成的生态系统的多样性。虽然,目前我们尚不清楚独立于人类的需求之外,生物多样性是否具有价值,但是经济学家和生态学家都承认生物多样性对人类具有价值。这两方面的专家也同意生物多样性由可以为人类利用和不可以为人类利用的两方面的要素 相似文献
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本文从生态系统多样性,物种多样性,遗传(基因)多样性,三个层次分析了我国生物多样性保护的现状,指出了生态系统不断破坏和恶化,生物多样性受威胁已成为我国目前最严重的环境问题之一。提出了对生物多样性与环境保护的合理开发,利用和保护措施。 相似文献
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全球人口持续增长以及节节攀升的人均资源消耗,导致了地球生物多样性的过度损耗,并且加剧了全球范围的气候变化、海洋酸化以及其他因人类行为所导致的环境影响.我们认为,保护生物多样性对维系人类生存和生态系统 相似文献
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生物多样性是人类赖以生存的物质基础,如何更好地保护生物多样性,实现人类社会与自然生态环境和谐发展已成为当今社会面临的重大议题。本文论述了我国生物多样性保护中存在的主要问题,提出环境善治是生物多样性破坏区域恢复和保护的有效模式,并进一步指出,生物多样性保护政策创制、生态系统与生物多样性经济学(TEEB)主流化、生物多样性保护的技术创新和以多元文化为基础的传统生态自然观是环境善治的有效途径。 相似文献
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<正> 近年来,从国外到国内,一门跨越生态学与人口学的边缘科学——人口生态学正在崛起。深入开展有关人口生态学的研究对于探讨我国社会主义人口规律,科学地解决人口问题,调整并维持岌岌可危的生态平衡,有重大的理论和实际意义。环境是一个有机统一的整体,人类生活于环境之中,同生物圈内其他生物一样,自成一个生态系统,即人类生态系统。人类生态系统是生物圈中最为重要的一种生态系统,他的物质流与能量流比其他生物系统要庞杂得多,必须引起人们予以特殊的关注。而生态学对人口学的意义,首先在于生态学研究的对象是生态系统,是人类赖于生存和发展的 相似文献
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Two different conditioning procedures, one appetitive and the other aversive, were used in separate attempts to demonstrate response to magnetic fields in the goldfish, Carassius auratus. Our results lead us to question those of an orientation experiment by Becker, although we recognize the possibility that goldfish may be sensitive primarily to magnetic field direction rather than intensity and that their directional sensitivity may be evidenced most readily by orientation in the field. 相似文献
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应急监测是突发性环境污染事故处置中的首要环节,是对污染事故及时、正确地进行应急处理、减轻事故危害和制定恢复措施的根本依据。文章从制定应急监测预案、加强应急监测能力建设、摸清污染源状况、加强应急培训和应急演练等方面对做好突发环境事件应急监测的快速响应作了简要的阐述,供大家探讨。 相似文献
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Croppers to livestock keepers: livelihood transitions to 2050 in Africa due to climate change 总被引:1,自引:0,他引:1
The impacts of climate change are expected to be generally detrimental for agriculture in many parts of Africa. Overall, warming and drying may reduce crop yields by 10–20% to 2050, but there are places where losses are likely to be much more severe. Increasing frequencies of heat stress, drought and flooding events will result in yet further deleterious effects on crop and livestock productivity. There will be places in the coming decades where the livelihood strategies of rural people may need to change, to preserve food security and provide income-generating options. These are likely to include areas of Africa that are already marginal for crop production; as these become increasingly marginal, then livestock may provide an alternative to cropping. We carried out some analysis to identify areas in sub-Saharan Africa where such transitions might occur. For the currently cropped areas (which already include the highland areas where cropping intensity may increase in the future), we estimated probabilities of failed seasons for current climate conditions, and compared these with estimates obtained for future climate conditions in 2050, using downscaled climate model output for a higher and a lower greenhouse-gas emission scenario. Transition zones can be identified where the increased probabilities of failed seasons may induce shifts from cropping to increased dependence on livestock. These zones are characterised in terms of existing agricultural system, current livestock densities, and levels of poverty. The analysis provides further evidence that climate change impacts in the marginal cropping lands may be severe, where poverty rates are already high. Results also suggest that those likely to be more affected are already more poor, on average. We discuss the implications of these results in a research-for-development targeting context that is likely to see the poor disproportionately and negatively affected by climate change. 相似文献
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N.Z. Lupwayi K.N. Harker G.W. Clayton J.T. O’Donovan R.E. Blackshaw 《Agriculture, ecosystems & environment》2009,129(1-3):171-176
Adoption of glyphosate-resistant canola (Brassica napus L.) has increased glyphosate applications to this crop, and concerns have been raised about unintended consequences of these multiple applications. A field trial was conducted to evaluate the effects of pre-seed and in-crop glyphosate and alternative herbicides on soil microbial community functional structure, diversity and biomass. Pre-seed treatments were 2,4-D, glyphosate and 2,4-D + glyphosate, and in-crop treatments were glyphosate applied once, glyphosate applied twice, ethalfluralin, ethalfluralin + sethoxydim + ethametsulfuron + clopyralid, and sethoxydim + ethametsulfuron. Rhizosphere and bulk soil was collected at flowering stage of canola and analyzed for bacterial community-level substrate utilization patterns and microbial biomass C (MBC). Where differences were significant, pre-seed application of both 2,4-D and glyphosate altered the functional structure and reduced the functional diversity of soil bacteria, but increased MBC. These effects were not necessarily concurrent. The reduction in functional diversity was due to reduction in evenness, which means that the soil where both pre-seed herbicides had been applied was dominated by only few functional groups. In 1 year, two in-crop applications of glyphosate also reduced the functional diversity of soil bacteria when applied after pre-seed 2,4-D, as did in-crop sethoxydim + ethametsulfuron following pre-seed glyphosate. Even though significant differences between herbicides were fewer than non-significant differences, i.e., there were no changes in soil microbial community structure, diversity or biomass in response to glyphosate or alternative herbicides applied to glyphosate-resistant canola in most cases, the observed changes in soil microbial communities could affect soil food webs and biological processes. 相似文献
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"它随处可见,从最大的海洋到最小的水坑,从最茂密的森林到最干旱的荒漠,从最富饶的沼泽到最高的山峰……它是一个活的银行账户,为人类全部事业和财富提供资本.它是什么?它就是……生物多样性."
翻开《生物多样性知识达人手册》的第一页,在"开头的话"中,你就能读到上面这一段饶有趣味的文字,让你不自觉地联想到我们所处的环境和我们赖以生存的地球.没错,这是一本新鲜出炉的、以生物多样性为主题的读物,用生动有趣的方式告诉你,什么是生物多样性?生物多样性为什么重要?你怎样才能保护好这个星球的生物多样性? 相似文献
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密西西比河是美国第一大河。它一路曲曲弯弯向着墨西哥湾蜿蜒流去.沿途形成广袤的洪泛平原,滋润着美国大陆41%的土地。水量也比美国其他河流都要多。密西西比河及其洪泛平原哺育着400多种野生动植物。北美地区40%的水禽都沿着密西西比河的路径迁徙。密西西比河对于美国。如同长江对于中国,无论从经济还是生物多样性保护等方面,其作用都是举足轻重。 相似文献