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991.
Data on the species composition, abundance, and biomass of macrozoobenthos in the rapids of a small river flowing in the foothills of the southwestern Kamchatka Peninsula are considered along with the results of quantitative analysis of structural rearrangements in the lithophilic community under the effects of changes in the granulometric composition of bottom sediments. Groups of lithophilic and pelophilic invertebrates typical of the metarithral of such rivers (e.g., chironomids of subfamilies Diamesinae and Prodiamesinae) are identified.Translated from Ekologiya, No. 2, 2005, pp. 120–125.Original Russian Text Copyright © 2005 by Leman, Chebanova. 相似文献
992.
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
993.
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
994.
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
995.
This study investigated the genetic relationships between the rare terrestrial orchid Diuris fragrantissima and three closely related purple flowered species using Amplified Fragment Length Polymorphisms. The purple-flowered species
were found to form individual phenetic clusters confirming recognition of D. fragrantissima at the rank of species. Levels of genetic variation were lower within D. fragrantissima than within its closest relatives but were higher than expected for severely bottlenecked species. Gene flow was detected
among all species (Nm = 2.34) and populations (Nm = 0.65) however low among population gene flow indicates that populations
may be at risk of divergence. This study has implications for the conservation of D. fragrantissima. 相似文献
996.
997.
This research surveyed human-impacted littoral forests in southeastern Madagascar to determine (i) how forest structural features, indicative of human impact, are related to total, utilitarian, and endemic tree diversity; (ii) the distribution, abundance, and demographics of tree species groups (i.e., total, useful, endemic) across the landscape; and (iii) the amount of basal area available per human use category. We also use these data to consider issues of sustainable use and how human impact may influence littoral forest tree community composition across the landscape. Within 22 transects of 400 m2 each, we recorded a total of 135 tree species and 2155 individuals. Seventy-nine species (58%) were utilitarian and 56 (42%) were nonutilitarian species. Of the 2155 individuals, 1827 (84%) trees were utilitarian species. We recorded 23 endemic species (17% of the total species) and 17 (74%) of these were utilitarian species. Basal area was significantly correlated with Shannon Weiner Index values for total (r = 0.64, P < 0.01), utilitarian (r = 0.58, P < 0.01), and endemic tree diversity (r = 0.85, P < 0.01). Basal area was significantly correlated with the Simpson’s index values for the endemic species (r = 0.74, P < 0.01). These correlations suggest that endemic tree species, of high global conservation value, may be the species group most influenced by changes in forest structure. Utilitarian species constituted 84% of the total basal area. The use category contributing the highest amount of basal area to the landscape was firewood. The results presented herein demonstrate that the landscape of southeastern Madagascar, commonly perceived as degraded, retains high value for both global conservation purposes and for local livelihoods. Thus, valuable opportunities may exist for developing conservation incentives that leverage both global and local conservation needs. 相似文献
998.
We made use of land cover maps, and land use change associated with urbanization, to provide estimates of the loss of natural
resource lands (forest, agriculture, and wetland areas) across the 168,000 km2 Chesapeake Bay watershed. We conducted extensive accuracy assessments of the satellite-derived maps, most of which were produced
by us using widely available multitemporal Landsat imagery. The change in urbanization was derived from impervious surface
area maps (the built environment) for 1990 and 2000, from which we estimated the loss of resource lands that occurred during
this decade. Within the watershed, we observed a 61% increase in developed land (from 5,177 to 8,363 km2). Most of this new development (64%) occurred on agricultural and grasslands, whereas 33% occurred on forested land. Some
smaller municipalities lost as much as 17% of their forest lands and 36% of their agricultural lands to development, although
in the outlying counties losses ranged from 0% to 1.4% for forests and 0% to 2.6% for agriculture. Fast-growing urban areas
surrounded by forested land experienced the most loss of forest to impervious surfaces. These estimates could be used for
the monitoring of the impacts of development across the Chesapeake Bay watershed, and the approach has utility for other regions
nationwide. In turn, the results and the approach can help jurisdictions set goals for resource land protection and acquisition
that are consistent with regional restoration goals. 相似文献
999.
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
1000.