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1.
裴盛基 《中国科学院研究生院学报》2002,(2)
中国是世界上生物多样性资源丰富的国家之一。作为全球性生物 巨大多样性"国家,中国具有多种多样的生态系统、植被类型、物种和遗传多样性。中国的植物尤其丰富,30,0 0 0种高等植物产于中国,其中乔、灌木 7,5 0 0种;中国的动物区系同样丰富。据统计已发现有 6,347种脊椎动物(包括 1,2 4 4种鸟类和 3,862种鱼类),特有植物物种多达 1 7,30 0种;特有脊椎动物 667种;中国西部 1 2个省、市、自治区,包括甘肃、贵州、陕西、四川、青海、云南 6省,广西壮族自治区、内蒙古自治区、宁夏回族自治区、新疆维吾尔族自治区和西藏自治区等 5个自治区以及重庆市。土地面积 6 98万km2 ,约占国土总面积的70 %;有全国 75 %的植物物种数和动物物种数。中国西部省区人口总数为 4 0 5亿,其中少数民族人口占相当比重。多民族文化状态造就了中国西部省区成为独特的生物 文化多样性地区;另一方面,中国西部省区面临农村贫困、自然资源与环境的退化和少数民族依然处于边缘状态的现实。本文讨论了中国西部省区的生物与文化多样性及其在经济发展方面的潜力。急需保护该地区的自然和文化,以达到可持续发展的目的。 相似文献
2.
农业生物多样性测度指标的建立与应用——以贵州省从江县为例 总被引：2，自引：0，他引：2
农业生物多样性是人类当前和未来产业发展、资源开发、战略性种质资源保存与利用、生物安全等的重要物质基础。然而,随着人口的增长,高产品种的推广,化肥、农药的过度施用以及政策变革和经济建设等原因,农业生物多样性不断遭到破坏或丧失,对其保护已成为全球可持续农业研究中的焦点。农业生物多样性的评价是有效保护农业生物多样性,合理利用其资源,促进区域可持续发展的关键。本文以Shannon-Wiener多样性指数、等级多样性测度为基础,对农业等级多样性测度指标进行了研究;引入信息增益的概念,对农业生物多样性信息增益的测度指标进行了研究,并用农业等级多样性、信息增益及其他多样性指标分析评价了贵州省从江县的农业生物多样性。结果表明从江县旱地植物共有36科86种及变种。按用途分,主要有食用植物29种,占总物种数的33.7%;药用植物20种,占23.3%;饲料植物5种,占5.8%;其它5种,占5.8%。多样性指数分析的结果为:旱地物种Simpson优势度指数为0.20,Margalef丰富度指数为4.35、Shannon-Wiener指数为2.27,Pielou均匀度指数为0.71。农业多样性分析结果为:旱地农业物种丰富度为0.13;农业物种多样性指数分别3.225和1.708。农业等级多样性指数与利用物种数的变化趋势基本一致,并与农业物种丰富度指数的变化趋势基本相符,但与信息增益的测度指标有所差异。 相似文献
3.
农业生物多样性测度指标的建立与应用 总被引：1，自引：1，他引：0
农业生物多样性是人类当前和未来产业发展、资源开发、战略性种质资源保存与利用、生物安全等的重要物质基础。然而,随着人口的增长,高产品种的推广,化肥、农药的过度施用以及政策变革和经济建设等原因,农业生物多样性不断遭到破坏或丧失,对其保护已成为全球可持续农业研究中的焦点。农业生物多样性的评价是有效保护农业生物多样性,合理利用其资源,促进区域可持续发展的关键。本文以Shannon-Wiener多样性指数、等级多样性测度为基础,对农业等级多样性测度指标进行了研究;引入信息增益的概念,对农业生物多样性信息增益的测度指标进行了研究,并用农业等级多样性、信息增益及其他多样性指标分析评价了贵州省从江县的农业生物多样性。结果表明从江县旱地植物共有36科86种及变种。按用途分,主要有食用植物29种,占总物种数的33.7%;药用植物20种,占23.3%;饲料植物5种,占5.8%;其它5种,占5.8%。多样性指数分析的结果为：旱地物种Simpson优势度指数为0.20,Margalef丰富度指数为4.35、Shannon-Wiener指数为2.27,Pielou均匀度指数为0.71。农业多样性分析结果为：旱地农业物种丰富度为0.13;农业物种多样性指数分别3.225和1.708。农业等级多样性指数与利用物种数的变化趋势基本一致,并与农业物种丰富度指数的变化趋势基本相符,但与信息增益的测度指标有所差异。 相似文献
4.
论生态学热点-生物多样性丧失的原因 总被引：1，自引：0，他引：1
生物多样性与人类的生产生活息息相关。然而,随着人口的增加和人类的经济活动,生物多样性的丧失正日益加剧,受到了国际社会的广泛关注,国内外对于生物多样性丧失的原因都开展了大量的研究工作。文章浅述了该领域的研究现状,从自然原因和人为原因两大方面综述了丧失原因,其中人为原因又分别从生境破坏、过度利用、环境污染、外来种入侵、土地利用变化（城市化和农业活动）等方面逐一论述,最后提出相关保护对策。 相似文献
5.
近20年来,我国生物多样性研究快速发展,在生物多样性志书编研、生物多样性起源与演化、生物多样性维持机制及与生态系统功能和服务的关系、生物多样性威胁因素及对全球变化的响应、生物多样性与生态安全,以及生物多样性研究平台建设等方面都取得了长足进步,但生物多样性科学方面的理论性突破仍较少。为促进生物多样性研究的进一步发展,我们建议:(1)加强生物多样性科学与生物多样性保护实践及可持续利用的结合;(2)加强新技术与新方法在生物多样性研究中的应用;(3)加强与扩大国际合作。 相似文献
6.
依据2012年2月至2012年11月三门核电站周边海域4个季节的调查数据,分析了该区域浮游植物的种类组成、丰度、优势种类与生物多样性等特征参数的季节变化。经显微观察,共鉴定出浮游植物4门49属109种,季节变化为夏季(73种)春季(65种)冬季(44种)秋季(39种);调查水域各站点浮游植物细胞丰度在2.44×104~2.70×107个/m3,平均细胞丰度为1.09×106个/m3,季节变化为夏季(3.72×106个/m3)春季(2.97×105个/m3)冬季(1.77×105个/m3)秋季(1.43×105个/m3);优势种17种,主要有中肋骨条藻(Skeletonema costatum)、中国盒形藻(Biddulphia sinensis)、虹彩圆筛藻(Coscinodiscus oculus-iridis)等;多样性分析显示,除夏季外,其他三个季节Shannon-Wiener指数(H’)均大于2,且冬季最高;细胞密度与水温、盐度的相关性并不显著而与p H值呈现正相关关系。 相似文献
7.
渭北高原植被保土保肥生态效益的计量研究 总被引：7，自引：0，他引：7
植被保土、保肥、保水功能是陆地生态系统最重要的生态服务 ,对于促进区域农业可持续发展具有基础性作用。该文在地理信息系统支持下 ,以通用土壤侵蚀方程 (ULSE)及植被指数 (C)为依据 ,按裸地侵蚀模数减植被覆盖侵蚀模数 ,测算了渭北高原植被保土、保肥的物质量 ,以保土、保肥物质量为基础 ,按等效应原则测算了植被保土、保肥的价值量。结果显示 ,渭北黄土高原植被每年保持表土 3 6 45× 1 0 8t,按等效应人工保土措施计算 ,植被保土价值量合 2 5 5× 1 0 8元 ;植被在保持表土的同时也保持了土壤有机质及N、P、K等土壤养分 ,按各类土壤养分含量及面积加权计算 ,每年可保持 45 7 2× 1 0 4 t有机质 ,植被保持有机质量相当于 1 3 0 6 2 9m3薪材、合 6 5 3× 1 0 8元 ;每年可保持全氮 3 5 45× 1 0 4 t、全磷 5 4 49× 1 0 4 t、全钾73 6 62× 1 0 4 t,植被保持的N、P、K按化肥市场价格计算 ,分别合 3 42× 1 0 8元、3 0 3× 1 0 8元、43 79× 1 0 8元。将该区植被保土、保持有机质、保持氮磷钾三者加起来 ,该区 4 2 6× 1 0 8km2 的植被整个保土保肥效益约5 9 3 2× 1 0 8元 ,这是植被为本区提供天然生态服务和自然资本。 相似文献
8.
福建省粮食作物气候-土壤生产力及人口承载量的研究 总被引：14，自引：0，他引：14
文章采用改进的农业生态区域法 ,计算全省 2 9个代表站水稻、小麦、甘薯 3种作物光温、气候及气候 -土壤生产力 ;将福建分成 6个农业自然区进行分析 ;根据对未来 2 0 1 0年及 2 0 5 0年人口、耕地的动态预测 ,计算各农业区农田的人口承载力。分析结果表明 :福建省目前、2 0 1 0年、2 0 5 0年人口分别为 32 6 1×1 0 4人、370 8× 1 0 4人、4 1 6 8× 1 0 4人 ,人均占有粮食分别为 31 1 2kg·a- 1 、30 9 2kg·a- 1 、32 6 3kg·a- 1 ,不足低消费水平 4 0 0kg·a- 1 ,若增加农业投入 ,未来的粮食能达到理想产量水平。为合理利用当地自然资源 ,明确农业投入方向和协调粮食需求平衡 ,提出对策及建议 :①建设旱涝保收田 ;②合理调整粮食布局 ,挖掘生物学产量潜力 ;③提高土壤肥力 ,促进作物高产 ;④改良品种 ;⑤严格限制非农业用地 ,控制人口增长。 相似文献
9.
全球生物多样性保护与持续利用的纲领性文件——《生物多样性公约》介绍 总被引：1，自引：0，他引：1
生物多样性是地球上生命经过几十亿年发展进化的结果,是人类赖以生存的物质基础。然而,随着人口的迅速增长,人类经济活动的不断加剧,作为人类生存最为重要的基础的生物多样性受到了严重的威胁。 在过去的2亿年中自然界每27年就有一种植物物种从地球上消失,每世纪有90多种脊椎动物灭绝。随着人类活动的加剧,物种灭绝的速度不断加快,现在物种灭绝的速度是自然灭绝速度的1000倍!很多物种未被订名即已灭绝,大量的基因丧失,不同类型的生态系统面积锐减。无法再现的基因、物种和生态系统正以人类历史上前所未有的速度消失。如果不立即采取有效措施,人类将面临着能否继续以其固有的方式生活的挑战。生物多样性的研究、保护和持续、合理地利用急待加强,刻不容缓。生物多样性的保护与 相似文献
10.
生物多样性是所有生物种类、种内遗传变异和它们的生存环境的总称,按照空间尺度可以划分为遗传多样性、物种多样性,生态系统多样性和景砚多样性.生物多样性是自然赋予人类的财富,对维持全人类的生存环境有十分重要的作用.近两个世纪以来人类的不合理开发和利用极大地破坏了世界的生物多样性.世界范围的生物多样性正在急剧下降.奉文综述了生物多样性的概念、生物多样性的价值、国内外生物多样性的测度方法、全球生物多样性的现状和生物多样性的保护,以便为保护和利用全球生物多样性提供知识支撑. 相似文献
11.
A research group led by Prof. ZHAI Qiwei from the Institute for Nutritional Sciences under the CAS Shanghai Institutes for Biological Sciences has discovered that even relatively low doses of resveratrol-a chemical found in the skins of red grapes in red wine-can improve the sensitivity of mice to the hormone insulin according to a report in the October issue of Cell Metabolism.…… 《中国科学院院刊(英文版)》2008,22(1):14-15
Aresearch group led by Prof. ZHAI Qiwei from the Institute for Nutritional Sciences under the CAS Shanghai Institutes for Biological Sciences has discovered that even relatively low doses of resveratrol--a chemical found in the skins of red grapes and in red wine--can improve the sensitivity of mice to the hormone insulin, according to a report in the October,2007 issue of Cell Metabolism. As insulin resistance is often characterized as the most critical factor contributing to the development of Type 2 diabetes, the findings“provide a potential new therapeutic approach for preventing or treating” both conditions, the researchers said. 相似文献
12.
Marjorie Armstrong-Stassen Margaret Landstrom Ramona Lumpkin 《The Information Society》1998,14(2):153-164
This study examined how students who had no prior experience with videoconferencing would react to the use of videoconferencing as an instructional medium. Students enrolled in seven different courses completed a questionnaire at the beginning of the semester and again at the end of the semester. Students at the origination and remote sites did not differ in their reactions toward videoconferencing but there was a significant difference for gender. Women reacted less favorably to videoconferencing. Compared to the beginning of the semester, students reported significantly less positive attitudes toward taking a course through videoconferencing at the end of the semester. There were no significant differences in students' attitudes toward videoconferencing across courses at the beginning of the semester but there were significant differences across the courses at the end of the semester. The results suggest the need for better preparation for both students and instructors. 相似文献
13.
A joint study by Prof. ZHANG Zhibin from the CAS Institute of Zoology his co-workers from Norway US Swiss have indicated that historical outbreaks of migratory locusts in China were associated with cold spells suggesting that China's projected climate warming could decrease the pest's numbers. The study was published in Proceedings of the National Academy of Sciences on September .…… 《中国科学院院刊(英文版)》2008,22(1):6-7
Ajoint study by Prof. ZHANG Zhibin from the CAS Institute of Zoology and his co-workers from Norway, US and Swiss have indicated that historical outbreaks of migratory locusts in China were associated with cold spells, suggesting that China＇s projected climate warming could decrease the pest＇s numbers. The study was published in Proceedings of theNational Academy of Sciences on 17 September, 2007. 相似文献
14.
Active biological molecules functional structures can be fabricated into a bio-mimetic system by using molecular assembly method. Such materials can be used for the drug delivery disease diagnosis therapy new nanodevice construction.…… 《中国科学院院刊(英文版)》2008,22(1):22-22
Active biological molecules and functional structures can be fabricated into a bio-mimetic system by using molecular assembly method. Such materials can be used for the drug delivery, disease diagnosis and therapy, and new nanodevice construction. 相似文献
15.
Caroline Haythornthwaite 《The Information Society》2001,17(3):211-226
A computer-mediated group is a complex entity whose members exchange many types of information via multiple means of communication in pursuit of goals specific to their environment. Over time, they coordinate technical features of media with locally enacted use to achieve a viable working arrangement. To explore this complex interaction, a case study is presented of the social networks of interactions and media use among members of a class of computer-supported distance learners. Results show how group structures associated with project teams dominated who communicated with whom, about what, and via which media over the term, and how media came to occupy their own communication niches: Webboard for diffuse class-wide communication; Internet Relay Chat more to named others but still for general communication across the class; and e-mail primarily for intrateam communication. Face-to-face interaction, occurring only during a short on-campus session, appears to have had a catalytic effect on social and emotional exchanges. Results suggest the need to structure exchanges to balance class-wide sharing of ideas with subgroup interactions that facilitate project completion, and to provide media that support these two modes of interaction. 相似文献
16.
《中国科学院院刊(英文版)》2008,22(1):2-3
CAS should stick to the principle of rendering service to, and giving impetus for, the development of China＇s science enterprise by making S＆T innovations, said CAS President LU Yongxiang. The CAS president made the remarks in a recent talk to communicate the gist of the winter session of the Party＇s Leading-member Group at CAS, which was held from 7 to 11 January in Beijing. 相似文献
17.
《中国科学院院刊(英文版)》2008,22(1)
With great care, Dr. ZHOU Zhonghe takes out a package wrapped by cotton tissue from a drawer and says: "This is the gem of our collections: the fossil of a bird that lived 125 million years ago!" Then, pointing at a tiny mound, he explains: "Look, this is the claw and that is the head. It was in the egg shell and ready to hatch ... The species fell into a family of waterside inhabitants." 相似文献
18.
Electronic data interchange (EDI) provides means for interorganizational communication, creates network externalities, requires an advanced information technology (IT) infrastructure, and relies on standards. In the diffusion of such innovations, institutional involvement is imperative. Such institutions contain governmental agencies, national and global standardization organizations, local government, and nonprofit private organizations like industry associations. The last type of organizations we call intermediating institutions. They intermediate or coordinate ("inscribe") the activities of a group of would-be adopters. Unfortunately, little is known of how these organizations shape the EDI diffusion trajectory. In this article we examine one specific type of intermediating organizations?industry associations?and how they advanced the EDI diffusion process in the grocery sectors of Hong Kong, Denmark and Finland. We identify six institutional measures, placed into a matrix formed by the mode of involvement (influence vs. regulation) and the type of diffusion force (supply push vs. demand pull), that can be mobilized to further the EDI diffusion. Industry associations were found to be active users of all these measures to varying degrees. Their role was critical especially in knowledge building, knowledge deployment, and standard setting. Furthermore, institutional involvement varied due to policy and cultural contingencies and power dependencies. 相似文献
19.
Leah A. Lievrouw 《The Information Society》2000,16(2):155-159
This essay focuses on universal service and the Internet as means to support social and political participation. The emphasis on access to telecommunications systems in conventional approaches to universal service is contrasted with access to content. A model of the information environment is described that accounts for the roles of content and conduit, both of which are necessary conditions to achieve true access. A method is outlined for employing information indicators to observe or measure the information environment. 相似文献
20.
Puay Tang 《The Information Society》1998,14(1):19-31
The increasing prospects of digital piracy has prompted the perceived need by electronic publishers to adopt technical systems of protection, and governments to reform their copyright laws. This article is a preliminary study of the management of intellectual property by electronic publishers, defined as those involved in the production of online databases, and CD-ROMs. It focuses on three main issues: (1) how electronic publishers view the increasing threat of piracy; (2) the methods of protection employed to protect intellectual property in digital format; and (3) the importance of technological protection of intellectual property in electronic publications. The analysis is based on a sample of 23 UK electronic publishers. The interviews revealed an interesting assortment of protection methods and did not show that technological protection was a preferred way. Instead, the means of protection, in addition to copyright law, comprised niche markets, pricing, trust, bad publicity, and nontechnical and technical means. 相似文献