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461.
Different criteria have been proposed for the rapid ecological evaluation of wooded areas. It is difficult, however, to determine the criteria most likely to yield results similar to those that would be obtained through detailed surveys and exhaustive evaluation. In order to identify such synthetic criteria, data from a detailed evaluation of Montreal Urban Community woodlots were studied with the help of multivariate analysis. This detailed evaluation was undertaken at two levels—woodlot unit and the woodlots themselves—using 16 different criteria.At the woodlot unit level, area and abundance indices of shade intolerant species in the tree layer could be used as synthetic criteria, while at the woodlot level the ecological value of the constituent units stand out as the first synthetic criterion. These results are compared with criteria proposed in the literature, and the use of multivariate analysis in ecological evaluation is briefly discussed. 相似文献
462.
目前新疆境内油田主要环境问题与对策 总被引:3,自引:0,他引:3
根据实际调查资料,分析了目前新疆境内油田的主要环境问题,并结合我区实际,提出了对策建议。 相似文献
463.
武隆县旅游开发中的生态安全对策研究 总被引:6,自引:0,他引:6
旅游开发中的生态安全问题与整个旅游产业的可持续发展是息息相关的。本文通过对重庆武隆旅游开发现状的调查,对其旅游开发过程中的生态安全问题对策进行了研究,以期对重庆旅游业的可持续发展,以及整个西部旅游业的可持续发展提供借鉴和参考作用。 相似文献
464.
Associating Ecosystem Service Losses with Indicators of Toxicity in Habitat Equivalency Analysis 总被引:1,自引:0,他引:1
Habitat equivalency analysis (HEA) was developed as a tool to scale mitigation or restoration when habitat is contaminated by hazardous substances or has been otherwise harmed by anthropogenic activities. Applying HEA involves balancing reductions in habitat quality against gains from restoration actions, and quantifying changes in habitat quality in terms of ecological services. We propose a framework for developing ecological service definitions and measures that incorporate knowledge about the impacts of chemical contaminants on biota. We describe a general model for integrating multiple lines of evidence about the toxicity of hazardous substances to allow mapping of toxicological inputs to ecological service losses. We provide an example of how this framework might be used in a HEA that quantifies ecological services provided by estuarine sediments contaminated with polycyclic aromatic hydrocarbons. 相似文献
465.
Assessing Ecological Integrity of Ozark Rivers to Determine Suitability for Protective Status 总被引:3,自引:0,他引:3
Preservation of extraordinary natural resources, protection of water quality, and restoration of impaired waters require a strategy to identify and protect least-disturbed streams and rivers. We applied two objective, quantitative methods to determine stream ecological integrity of headwater reaches of 10 Ozark rivers, 5 with Wild and Scenic River federal protective status. Thirty-four variables representing macroinvertebrate and fish assemblage characteristics, in-stream habitat, riparian vegetation, water quality, and watershed attributes were quantified for each river and analyzed using two multivariate approaches. The first approach, cluster and discriminant analyses, identified two groups of river with only one variable (% forested watershed) reliably distinguishing groups. Our second approach employed ordinal scaling to compare variables for each river to conceptually ideal conditions that were developed as a composite of optimal attributes among the 10 rivers. The composite distance of each river from ideal was then calculated using a unidimensional ranking technique. Two rivers without Wild and Scenic River designation ranked highest relative to ideal (highest ecological integrity), and two others, also without designation, ranked most distant from ideal (lowest ecological integrity). Fish density, number of intolerant fish species, and invertebrate density were influential biotic variables for scaling. Contributing physical variables included riparian forest cover, water nitrate concentration, water turbidity, percentage of forested watershed, percentage of private land ownership, and road density. These methods provide a framework for refinement and application in other regions to facilitate the process of establishing least-disturbed reference conditions and identifying rivers for protection and restoration. 相似文献
466.
土地资源现状存在的问题:耕地不断减少、土地利用结构不合理、土地营养失调、土地污染严重.保护措施:科学编制土地利用规划,严格使用审批手续;有效控制土地减少趋势,抑制交通,城建用地过快增长,合理开发荒地、闲散废弃地和复垦;完善法制建设,严格依法管理、调整现行土地税费体系;采取有力措施防治乡镇、企业水污染、化肥污染、应用薄膜污染等. 相似文献
467.
文章分析论述了我国环保产业发展中存在的诸如:规模小,技术开发能力薄弱;产业分布范围广,结构不合理,市场混乱等问题。针对此类问题提出建设性意见及应对措施。 相似文献
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