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951.
中国中部六省生态足迹实证分析 总被引:24,自引:0,他引:24
生态足迹是一种定量评价区域资源可持续利用的生态经济指标,其方法紧扣可持续发展的理论,是一个涉及系统性、公平性和延续性的综合指标,具有可度量性、计算合理性和结果可比性等优点。在介绍其概念、计算模型的基础上,针对中国中部六省的资源和能源消费状况进行了实证分析。研究表明:本区2004年人均生态足迹1.793hm2,生态承载力为0.488hm2·人-1,生态足迹需求与供给的比例为3.677∶1,人均生态赤字为1.305hm2,说明中部地区的发展已经超出了生态承载力的阈值;该区生态足迹多样性指数1.336,万元GDP足迹1.982hm2,生态协调系数1.227等,也反映了中部地区处于一种不可持续的发展状态。 相似文献
952.
RIVPACS models for predicting the expected macroinvertebrate fauna and assessing the ecological quality of rivers 总被引:4,自引:0,他引:4
The European Union Water Framework Directive recognises the need for and value of biological monitoring. This paper reviews the modelling approach known as River Invertebrate Prediction and Classification System (RIVPACS
for assessing the ecological quality of river sites using macroinvertebrate sampling. The RIVPACS philosophy is to develop statistical relationships between the fauna and the environmental characteristics of a large set of high quality reference sites which can be used to predict the macroinvertebrate fauna to be expected at any site in the absence of pollution or other environmental stress. The observed fauna at new test sites can then be compared with their site-specific expected fauna to derive indices of ecological quality. All methodological decisions in any such model development have implications for the reliability, precision and robustness of any resulting indices for assessing the ecological quality and ecological grade (‘status’) of individual river stretches. The choice of reference sites and environmental predictor variables, the site classification and discrimination methods, the estimation of the expected fauna, and indices for comparing the agreement, or lack of it, between the observed and expected fauna, are all discussed. The indices are assessed on the reference sites and on a separate test set of 340 sites, which are subject to a wide range of types and degrees of impairment. 相似文献
953.
This paper explains the application of structural path analysis (SPA), an input–output-based technique for measuring flows in ecological and linked ecological–economic networks. Previous methods of input–output flow analysis have concluded with aggregate indexes relying on the summing feature of the Leontief inverse in order to completely account for throughflows along a multitude of inter-compartmental paths. This paper shows that for most linear dissipative networks, a manageable number of paths of limited length exist that cover in the order of 99% or more of total throughflow. These paths can be conveniently extracted, enumerated and ranked using SPA. 相似文献
954.
We investigated quantitatively the sensitivity of plant species response curves to sampling characteristics (number of plots, occurrence and frequency of species), along a simulated pH gradient. We defined 54 theoretical unimodal response curves, issued from combinations of six values for optimum (opt = 3, 4, …, 8), three values for tolerance (tol = 0.5, 1.0, and 1.5, sensu ter Braak and Looman [ter Braak, C.J.F., Looman, C.W.N., 1986. Weighted averaging, logistic regression and the Gaussian response model. Vegetatio 65, 3–11]), and three values for maximum probability of presence (pmax = 0.05, 0.20, and 0.50). For each of these 54 theoretical response curves, we built artificial binary data sets (presence/absence) to test the influence of species occurrence, frequency, or number of available plots. With real data extracted from EcoPlant, a phytoecological database for French forests [Gégout, J.-C., Coudun, Ch., Bailly, G., Jabiol, B., 2005. EcoPlant: a forest sites database linking floristic data with soil characteristics and climatic conditions. J. Veg. Sci. 16, 257–260], we compared the ecological response of 50 plant species to soil pH, based first on a small data set (100 randomly sampled plots), and then based on the whole data set available (3810 plots). 相似文献
955.
The ecological constraints model predicts that daily travel distance and home range size of social animals will increase as group size increases in order to meet the dietary needs of additional group members. This theory has been supported more predominantly by studies of frugivorous primate species than by studies of folivorous species. We examined the ranging patterns of mountain gorillas in Bwindi Impenetrable National Park, Uganda, who include both herbaceous vegetation and fruit in their diet, to determine how ecological, behavioral, and social parameters influence movement patterns. Data were collected from three groups of gorillas with overlapping home ranges at a low-altitude location (1,450–1,800 m) and one group at a high-altitude location (2,100–2,500 m) in Bwindi from September 2001 to August 2002. We analyzed daily travel distance and home range size in relation to group size, while also considering patterns of frugivory, rainfall, and location (proxy for food availability) within the park. Both daily travel distance and home range size were positively related to group size. In addition, the degree of frugivory positively influenced daily travel distance and home range size, while rainfall negatively influenced daily travel distance only. Finally, groups at the low-altitude location, with higher fruit availability, traveled less than the group at the high-altitude location. These results demonstrate that mountain gorillas in Bwindi provide support for the ecological constraints model, but further studies are needed to determine how fine-scale spatial and temporal availability of food resources influence movement patterns. Ranging patterns of Bwindi gorillas are compared to those observed in other gorilla populations in the context of the ecological constraints model.Communicated by D. Watts 相似文献
956.
Restoration ecology of riverine wetlands: I. A scientific base 总被引:10,自引:0,他引:10
957.
黄河口水动力作用的最显著特点是径流方向(WE)和潮流方向(SN)近于垂直。这一特点有利于三角洲的横向扩展[1],但另一方面,由于沿岸流异常发育,加快了河口沉积速度,促进了拦门沙的发育,使河口处的河床抬高,泄流不畅,不利于黄河口外水下河道的自然下切延伸,最终诱发改道。米草生态工程可以通过防止泥沙沿岸搬运,降低海水含沙量,从而降低拦门沙的发育速度,保护黄河水下河道,最终起到降低河口变动频率,防治黄河改道的作用。 相似文献
958.
吐鲁番盆地的生态灾害具有种类多、危害面广、危害程度深等特征,并严重制约着该区绿洲经济的持续稳定发展。本文分析了每种生态灾害发生的原因、危害程度及地区分布,并提出了生态灾害调控的基本原则;综合整体性、区域分异性、持续性.最后探讨了该地生态灾害调控的一些具体措施。 相似文献
959.
Larry Larsen Terri Morrell David Wood Meghan Gallione Bruce Guerard Judith Karinen Kip Petersen Frederick Steiner 《Environmental management》1991,15(4):531-548
This is the second of three articles prepared to explain the Teller County growth management process. As part of an ongoing
growth management process in Teller County, Colorado, opportunities and constraints for development and conservation were
identified. The scenic mountain county faces a number of issues because of growth. The recognition of those issues has resulted
in the goal to direct future growth to the most appropriate and cost-effective places. To determine those places that are
best for new development, thorough ecological inventories were conducted for the entire county as well as for the City of
Woodland Park area. From these inventories, environmentally sensitive areas were identified. The environmentally sensitive
areas were considered constraints in conducting suitability analyses for a variety of potential land uses. The suitability
analyses resulted in the identification of opportunities for future growth in Teller County generally as well as the more
specific Woodland Park planning area. This article, like the other two, is part of a reflective analysis by the planners who
were involved.
Paper 2 in a series 3. 相似文献
960.
Alexei Sankovskii 《Environmental management》1992,16(3):283-287
According to the suggested approach to the evaluation of natural objects current human needs should not be used in evaluation
procedures. The ecological value of natural objects (communities and ecosystems) is proportional to the probabilities of disappearance
associated with particular sets of objects. The ecological value is estimated using data on relative fragility, uniqueness,
size of regeneration unit for defined types of objects, and intensity of destructive factors. The ecological value of a specific
territory is equal to the sum of the values that are attached to the local objects situated at this territory. 相似文献