نتایج جستجو برای: ecological indices
تعداد نتایج: 181372 فیلتر نتایج به سال:
Marine monitoring: Its shortcomings and mismatch with the EU Water Framework Directive's objectives.
The main goal of the EU Water Framework Directive (WFD) is to achieve good ecological status across European surface waters by 2015 and as such, it offers the opportunity and thus the challenge to improve the protection of our coastal systems. It is the main example for Europe's increasing desire to conserve aquatic ecosystems. Ironically, since c. 1975 the increasing adoption of EU directives ...
Urban ecological vulnerability is measured on the basis of ecological sensitivity and resilience based on the concept analysis of vulnerability. GIS-based multicriteria decision analysis (GIS-MCDA) methods are used, supported by the spatial analysis tools of GIS, to define different levels of vulnerability for areas of the urban ecology. These areas are further classified into different types o...
Discusses the interaction between socio-economic systems and their natural environment, by examining the indicators of sustainable development. Areas covered by the operationalization of sustainable development indicators; Details on the global nature of environmental problems; Important strategy of the operationalization of sustainable development; Link between economic data and ecological ind...
Biotic indices have become key assessment tools in most recent national and trans-national policies aimed at improving the quality of coastal waters and the integrity of their associated ecosystems. In this study we analyzed 90 published biotic indices, classified them into four types, and analyzed the strengths and weaknesses of each type in relation to the requirements of these policies. We i...
Small mammals can be an important bioindicator of ecosystem health. They serve as both predator and prey in many ecosystems. By means of live trapping and nest monitoring, we studied the ecological relationships between small mammals, avian nest survival, and vegetation composition and structure on six private ranches in the Sandhills of Nebraska during 2004. Our study documented six species (1...
Three multi-metric benthic macrofauna indices were used to assess marine benthic ecological quality status (EcoQS) according to the European Water Framework Directive, in seven pollution gradients mainly, western Scandinavia. The impacts included organic load, hypoxia, metals, urban effluents and physical disturbance. The indices responded in a similar threshold fashion, irrespective of impact ...
The ecological impacts of anthropogenic activities on aquatic environments have led to the development of new methods of environmental monitoring (Cohen et al 1993, Kelly and Whitton 1995). Benthic algae represent a ubiquitous group of photosynthetic organisms that play a pivotal role in stream food webs but may also be used for observing long-term trends in community changes that can occur bec...
Green space is important for the maintenance of the ecological dimension of a sustainable urban landscape. Therefore, in order to figure out the relationship between the greening of urban parks and bird diversity, we used 5 avian ecological diversity indexes, such as Species richness, Abundance, ShannonWeiner diversity index, Evenness, and Margalef’s richness indices, to evaluate the functional...
Diversity indices, although designed for comparative purposes, often cannot be used as such, due to their sample-size dependence. I t is argued here that this dependence is more pronounced in h~gh divers~ty than in low diversity assemblages and that indices more sensitive to rarer species require larger sample sizes to estimate diversity with reasonable precision than indices which put more wei...
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