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881.
岩溶地区作为一个特殊的地理环境单元,具有环境承载量低、地表崎岖破碎、植被生长困难、生态环境脆弱的特点。该文以岩溶地貌发育典型、碳酸盐岩出露面积广的贵州省为例,论述了岩溶区生态环境脆弱性类型划分的主要原则,探讨了脆弱性类型划分的指标并进行了量化。在此基础上,用灰色关联度分析确定了各影响因子(指标)的权重,经过综合评判,笔者把贵州岩溶区生态环境脆弱性类型划分为5类:剧烈脆弱区、强度脆弱区、中度脆弱区、轻度脆弱区和潜在脆弱区,并针对各脆弱性类型区的特点,提出了相应的防治对策。 相似文献
882.
The aim of this study is to determine the total metal (aluminum, copper, manganese, nickel, lead, zinc, cadmium, iron, mercury) contents of dominant shrimp species and sediments present at 1–50 m depths of the Northern Inner Shelf of the Sea of Marmara. Shrimp and sediment samples were collected from four regions (Büyükçekmece, Silivri, Tekirda?, ?arköy) and from different depths (1, 5, 10, 20, 30, 50 m) at each region in September and November of 2003. Three shrimp species [Palaemon adspersus (Rathke, 1937), Palaemon serratus (Pennant, 1777), Parapenaeus longirostris (H. Lucas, 1846)] were identified to be dominant as a result of the examination on the obtained samples. Heavy metal contents of these three species were determined and the results were compared with the acceptable treshold values of the Seafood Standards and also with available literatures. The Cu contents were found to be higher than the treshold limits in all samples except P. longirostris from Silivri, also the Cd contents in all samples except P. adspersus from Büyükçekmece, the Zn contents only in P. adspersus and P. longirostris from Tekirda?, and the Pb contents in all species from all regions. These high values are the indicator of industrial pollution. There is not any data in the Seafood Standards about Mn, Ni, Fe and Al contents in shrimp species. The values of these metal contents were given in the present study. The examination of total metal distributions in bottom surface sediment samples in the Northern Inner Shelf of the Sea of Marmara showed that the determined values were higher than the shale average at some depths of examined stations. 相似文献
883.
Based on the theory of ecological footprint this paper analyzed the ecological economic system in Funing County in the view
of demands of economic system to natural resource and supply of ecosystem for natural resources. It was proposed that the
concept of ecological deficit (ecological remainder) per ten thousands yuan GDP be used to evaluate development of ecological
economic system. With a synthesis appraisement to the ecological economic system using entire-array-polygon method combined
with Ulanowicz development ability and with ecological deficit (ecological remainder) per ten thousands yuan GDP, it provids
a theoretical base for reconstructing and managing of demonstration eco-region. 相似文献
884.
Zhang W 《Environmental monitoring and assessment》2007,124(1-3):253-261
Both direct and indirect ecological interactions may occur in an ecosystem with large numbers of taxa. Traditional food web
technique is a popular tool to measure the quality and health of the environment. Much of works must be done before constructing
a food web for an ecosystem especially with many taxa. This food web is generally specific for some ecological interactions
and fixed for a set of given species. It is therefore not an effective method for dynamic and prompt assessment of environment.
Ecological interactions and their interactive intensity may be detected by sampling biological taxa in the field and by detecting
various between-taxa distances or similarities. Network may clearly exhibit the complex interactions among biological taxa.
Statistic tests on various distance or similarity measures and computer designs are required to infer the {network. We develop
an algorithm and software to infer the network of direct or indirect ecological interactions in ecosystem. It is a prompt
and effective tool in monitoring and assessment of the environment. A redundant network may be inferred and drawn by computer
based on the statistic tests on sampling data or the pathway information given in HTML file. Dominant taxa may be found in
the network. In total of 16 distance and similarity measures, including Euclidean distance, Manhattan distance, Pearson correlation,
partial correlation, point correlation, linkage coefficients, Jaccard coefficient etc., are provided to detect taxa pairs
with significant parametric or nonparametric similarities, based on randomization tests and ordinary statistic tests. Criteria
to use distance and similarity measures are discussed. 相似文献
885.
The current lack of a working resource management plan Magdalena Bay (southern Baja California, Mexico) has weakened attempts
to set priorities among resource users and has contributed to: reduced fish stocks, land and marine contamination, and declines
in the ecological integrity of the bay of 170 000 ha and its vast mangrove lagoon systems. The government agencies responsible
for maintaining ecological integrity and managing marine resource use have not been successful in addressing these problems
due to jurisdictional ambiguities, lack of community support, and lack of manpower for monitoring and enforcing policies.
A framework was designed by the authors to work toward an approach for balancing between community development and conserving
ecological integrity at the local level in the peripheral and central zones of the Magdalena Bay system. The goal of this
framework was to suggest a basis for setting management priorities that included the perceptions and preferences of stakeholder
groups with regard to direct threats to the environmental health of the study areas. To achieve this goal a crossdisciplinary
study of the central and peripheral zones was used to examine factors that influence current resource use and the environmental
state in these two regions of the bay system. Insights into the preferences and perceptions of stakeholder groups with regard
to management priorities were acquired using the key informant technique. The results revealed potential conflicts with regard
to preferred management priorities between stakeholder groups, as well as polarities within stakeholder groups themselves. 相似文献
886.
887.
Marine protected areas (MPAs) have become a key component of conservation and fisheries management to alleviate anthropogenic pressures. For MPA networks to efficiently promote persistence and recovery of populations, ecological connectivity, i.e. dispersal and movement of organisms and material across ecosystems, needs to be taken into account. To improve the ecological coherence of MPA networks, there is hence a need to evaluate the connectivity of species spreading through active migration and passive dispersal. We reviewed knowledge on ecological connectivity in the Baltic Sea, Kattegat and Skagerrak in the northeast Atlantic and present available information on species-specific dispersal and migration distances. Studies on genetic connectivity are summarised and discussed in relation to dispersal-based analyses. Threats to ecological connectivity, limiting dispersal of populations and lowering the resilience to environmental change, were examined. Additionally, a review of studies evaluating the ecological coherence of MPA networks in the Baltic Sea, Kattegat and Skagerrak was performed, and suggestions for future evaluations to meet management needs are presented.Supplementary InformationThe online version contains supplementary material available at 10.1007/s13280-021-01684-x. 相似文献
888.
本溪县农业面源污染现状及防治对策 总被引:4,自引:1,他引:3
通过科学的调研数据,重点分析了本溪县农药、化肥和农膜造成的环境污染。调查结果表明,本溪县农药、化肥和农膜的大量施用,虽然可以提高农作物的产量,但也会对人、土地、水体和生物等产生诸多不利的影响,从而提出相应的治理对策。建议发展生态农业,加强监督管理,研究制定相应的污染控制政策与措施。 相似文献
889.
荒漠生态环境监测刍议 总被引:14,自引:1,他引:13
讨论了荒漠生态环境监测的基本概念和原则 ,并针对新疆荒漠生态环境监测工作的现状 ,提出了今后工作的总体设想和若干展望 ,对我国荒漠生态环境监测工作的开展具有一定的启示作用。 相似文献
890.
基于RS的荒漠景观空间格局的研究 总被引:4,自引:0,他引:4
利用NOAA气象卫星五波段遥感数据作主要信息源,经图像增强处理和解译,获得区域景观类型图。在完成景观类型图的数字化输入手,采用景观生态学的方法,对研究区域进行景观空间格局指标的计算机测定,筛选、建立了一套度量景观生态空间格局变化的评价指标体系。 相似文献