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941.
生物多样性保护与可持续发展 总被引:1,自引:0,他引:1
刘志敏 《中国环境管理干部学院学报》2007,17(2):17-18,50
本文就生物多样性保护的重要性进行了论述,并介绍了我国生物多样性特点,强调了生物多样性保护的迫切性,阐明了生物多样性对可持续发展的重要性。 相似文献
942.
多元文化资源整合与区域文化旅游创新发展——以云南丽江为例 总被引:3,自引:0,他引:3
以云南丽江为例,指出类似丽江的诸多西部多民族交错聚居区在文化旅游二次创业过程中突出自身区域主体民族文化特色的同时,必须要重视非主体民族文化资源的保护与开发,让各民族社区参与能力的塑造和培育都能在旅游开发中得到协调发展。这既是文化多样性对区域文化旅游资源整合重构的内在发展要求,也是区域旅游在二次创业中发挥扩散效应的重要导向。 相似文献
943.
土地的集约利用对社会发展具有重要的意义,研究土地集约利用空间差异可以更有效地提高土地利用水平。根据新一轮土地利用规划大纲要求和各区域土地利用实际,建立土地集约利用评价指标体系,确定土地集约利用评价的计算方法,包括数据的量化、标准化及综合计算模型,最后得出各地区土地集约利用程度。运用上述方法对孝感市建设用地集约利用空间差异进行分析,找出了其土地利用方面的问题和优势,为下一步改造提供依据和方向。 相似文献
944.
贵州山区是我国一个植物多样性较丰富的地区,仅野生观赏植物(含园林及行道绿化,美化树种)就有300多种,其中120多种属珍稀受危观赏物种。文章着重对36种主要珍稀濒危观赏植物的分布、生境、濒危类型、程度等进行了分析,并从观赏植物本身的生理生态习性、贵州山区生境本底的严酷性(土壤瘠薄,可有效利用的地表水匮乏等)、人类不合理干扰活动(如过渡采收、毁林垦荒等)方面探讨了该地区观赏植物多样性的受危原因。在此基础上,结合目前西部大开发中生态建设的要求,提出了该地区受危观赏植物的保护对策。 相似文献
945.
外来物种入侵及其环境法律调控准则 总被引:12,自引:0,他引:12
随着世界经济、贸易和交通高度发达的影响,外来物种入侵活动且益加剧,已尼成为威胁我国生物多样性与生态环境的重要因素之一,对我国的一些地区造成了巨大的生态和经济损失。有关外来入侵物种管理的立法应贯彻风险预防原则。 相似文献
946.
Roger L. Kaesler Edwin E. Herricks 《Journal of the American Water Resources Association》1977,13(1):125-135
ABSTRACT: Brillouin's equation (H) for species diversity from information theory is to be preferred for the purposes of applied ecology over the equation of Shannon (H′) or the more commonly used approximate equation (H″). By its use, the difficult problem of delimiting the extent of the community being sampled in a stream survey can be avoided. Moreover, Brillouin's equation gives the exact diversity of the fully censused collection, whreas Shannon's diversity can only be approximated with a biased estimator. If we regard a sample as a message from the environment to the ecologist, Brillouin's equation is the proper one for computing its diversity. The product moment correlation coefficient between Brillouin's H for the total number of individuals from a group of samples and for randomly chosen subsets of 100 individuals from each sample was nearly as high as the correlation between H and H″ based on the total samples. This indicates that small sample sizes may give a useful diversity index. Replicated subsamples show that much smaller samples than are normally used can discriminate between communities from polluted and unpolluted environments. The use of smaller samples should reduce the cost of stream surveys. 相似文献
947.
ABSTRACT: Longitudinal succession indicates that diversity and species richiess of fish communities increases with increasing river size (increasing habitat complexity and environmental stability). Cultural impacts tend to decrease diversity, species richness, and evenness. To assess the impacts of cultural events on the fish community of a river system, the bias caused by longitudinal succession was removed by normalizing diversity indices and species richness values for river size. The relationships between an impact index and the community parameters of evenness, normalized diversity, and normalized species richness were determined by regression analysis. Similar relationships were determined using nonnormalized data, and the results compared. The two sets of regressions were similar in terms of variance explained. Evenness, which is unaffected by longitudinal sucession, appears to be the most impact sensitive parameter. A major source of error and confusion rsults from introduced species which are simultaneously sources of biological impact and a component of the community. Numbers of introduced species tend to increase with both impact and river size. 相似文献
948.
Jan Salick 《Environmental management》1983,7(1):85-89
The natural histories of crop-related wild species in their native habitats can be used to develop novel pest management strategies. Traditionally, such information has provided insights for biological control, plant breeding, crop management, and applied ecology Further insights can be garnered. 相似文献
949.
Horst F. Siewert Carla J. Miller Byron G. Torke 《Journal of the American Water Resources Association》1989,25(3):685-689
ABSTRACT: Water samples and macroinvertebrates were collected from Finley Creek, Indiana, both before and two years after the cleanup of a nearby hazardous waste site. Water quality constituents were compared between years. Below the disposal site higher concentrations of constituents were found before and after the cleanup. However, two years after the cleanup, an improvement of water quality was observed. Total dissolved solids decreased by 52% and macroinvertebrate taxa increased by 44%. 相似文献
950.
R. Christian Jones Christopher C. Clark 《Journal of the American Water Resources Association》1987,23(6):1047-1055
ABSTRACT: The impact of urbanization on stream insect communities was determined by sampling 22 sites in northern Virginia representing a range of human population densities. Watershed development had little effect on the total insect numbers (no./m2), but shifted the taxonomic composition markedly. Relative abundance of Diptera (mainly chironomids) increased at more highly urbanized sites, while most other insect orders including Ephemeroptera (mayflies), Coleoptera (bettles), Megaloptera (dobsonflies), and Plecoptera (stone-flies) decreased. Trichoptera (caddisfiles) exhibited a variable response. Genus diversity and richness (number of genera) were significantly higher in less urbanized streams. Two genera of chironomids were positively correlated with increased urbanization, while 14 other genera (scattered through several orders) were negatively related to human population density. Principal components analysis demonstrated a gradient from more urbanized to less urbanized stations based on generic and order level biological data. Results of this study indicate that watershed urbanization has a major impact on benthic insect communities even in the absence of point source discharges. 相似文献