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891.
生态足迹方法在中国应用的案例初探 总被引:3,自引:0,他引:3
生态足迹方法通过估算维持人类生存的自然资源消费量和同化人类产生的废弃物所需要的生态性生产空间面积大小,并与给定人口区域的生态承载力进行比较,衡量区域的可持续发展状况。本文介绍了生态足迹模型的理论依据和计算方法,从模型方法应用范围,计算所需资料和模型自身三方面分析了生态足迹方法在我国应用中存在的问题和方法本身的不足。详细分析和比较了生态足迹方法在我国不同省市及地区的应用案例,结果表明,经济比较发达地区很大程度上需要通过地区贸易从不发达地区输入生态足迹,因而加重了不发达地区的生态负担。 相似文献
892.
893.
This paper presents the main results of two studies of contrasting natural and man-induced conditions along the Pacific coast
of Baja California (Mexico), based on the assumption that ecological insight can be obtained from man-induced modifications
insofar as relevant activities are explicitly addressed as parts of the systems under study. The study is concerned with a
fragmented coastal succulent-sage scrub and showed that several patches of different size and age may harbor as many species
as non-fragmented areas, and that 83% of the original species assemblage persisted in the fragments, in which the invasion
by opportunistic exotic species may not progress beyond certain limits. The study of dune-backed and urban-backed beaches
showed a significantly greater abundance of the Snowy Plover (Charadrius alexandrinus) at the dune-backed beach, where a much more active back-shore feeding of adult birds and the only evidences of breeding
occurred. Both studies refer to landscape features of regional concern and its results may be used in conservation management.
The results on fragmented coastal succulentsage scrub may encourage alternative urban designs that keep patches of the original
landscape, thus meeting existing requirements of low density urban development for most of the coastal succulent-sage scrub
area. The evidence presented on the negative effects of dune destruction on the abundance, feeding and reproductive performance
of a threatened bird species has a bearing on the topic of biodiversity management. It may also contribute to the conservation
of the coastal dunes system. 相似文献
894.
895.
The simplicity of many bioeconomic models has been criticised several times, due to their lack of realism resulting from a deterministic nature and a single-species focus. In this context it was interesting to test the financial sensitivity of bioeconomic modelling against fairly well documented ecological effects in mixed forests. For this purpose our study linked existing results of ecological research with bioeconomic modelling. The presented methodological approach could not only show the importance of considering ecological effects in bioeconomic models; it in fact enabled prioritising ecological research from a financial point of view.In a first step, the possible influence of the tree species mixture on forest stand resistance, productivity and timber quality was derived from existing studies. In a second step, the available Monte Carlo simulations for Norway spruce (Picea abies [L.] Karst.) and European beech (Fagus sylvatica L.), simulated under site conditions and risks typical of southern Germany, were extended by the mentioned ecological effects and then evaluated from a financial perspective.The results showed a clear influence of all tested ecological effects on the financial indicators, financial risk and return. While testing each ecological effect separately, an increased resistance against wind, snow and insect attacks had the greatest influence on financial risk and return. It over-proportionally enhanced the financial return while simultaneously the financial risk was reduced. In contrast, a degraded timber quality could eliminate the positive effect of risk compensation in mixed forests almost completely. The least influence on the financial indicators finally showed a changed volume growth in mixed forests.A combination of the separately tested ecological effects (increased resistance, changed volume growth and decreased timber quality), between both tree species, underlined the dominating importance of the stand resistance. The integration of ecological effects, induced by interdependent tree species, in our bioeconomic model resulted in significantly lower financial risk than ignoring these effects. Moreover, the financial return of mixed stand variants with a proportion of Norway spruce greater than 60% even exceeded that of the most profitable pure stand.In conclusion this paper clearly confirmed that ignoring ecological effects in bioeconomic models could lead to seriously biased financial results. While a changed volume growth proved rather to be of minor importance for European beech/Norway spruce stands, tree resistance and timber quality may change the financial results significantly. 相似文献
896.
897.
塔里木河流域生态脆弱性评价研究 总被引:49,自引:1,他引:48
塔里木河流域受自然及人为因素的影响,局部地区生态退化问题突出,从景观生态学的干扰性质理论和恢复生态学的观点出发,选择水资源系统、土地资源系统及植被资源系统及其10个综合性敏感因子对流域生态的敏感性及恢复力进行分析,并确定敏感因子的定量指标,定性代码及其权重和阈值,通过算术对数插值对敏感因子实际值进行规范化处理,并构建生态胁迫度。结果表明,塔里木河三源流阿克苏河流域、叶尔羌河流域、和田河流域及于流区的上、中、下游区生态胁迫度分别为0.13、0.25、0.30、0.31、0.57及0.84,在评价分级标准的限定下,其对应的生态脆弱性程度依次为轻微脆弱、一般脆弱、一般脆弱、一般脆弱、中等脆弱及严重脆弱。 相似文献
898.
经济开发区规划的合理性分析 总被引:1,自引:0,他引:1
一个经济开发区规划与所在大区域总体规划通常是密切相关的 ,开发区规划的合理与否直接影响到其所在大区域的可持续发展 ,因此对开发区规划的合理性进行分析是很有必要的。本文对开发区规划合理性分析的内容和工作程序进行了探讨 ,主要包括两部分内容 :开发区规划与区域总体规划的相容性分析和开发区规划布局的合理性分析 相似文献
899.
区域尾水控制初探--以昆山市为例 总被引:1,自引:0,他引:1
该文提出了“三级控制、三级标准”的区域水污染控制模式 ,分析了区域尾水控制的定位及意义。对区域尾水控制的三种主要方式做了较为详细的对比分析 ,并针对昆山市实际情况 ,初步构建了昆山市尾水导流方案。 相似文献
900.