排序方式: 共有2条查询结果,搜索用时 0 毫秒
1
1.
Al-Zamel AZ Al-Sarawi MA Khader SR Al-Rifaiy IA 《Environmental monitoring and assessment》2009,149(1-4):395-409
Quantitative analyses of recent benthic foraminiferal assemblages (living and dead) were carried out on the surface sediments of Sulaibikhat Bay. Marked contrast in foraminiferal assemblages between the shallow tidal mudflats and the deep tidal channel and their relation to the extent of pollution were observed. Cluster analysis of quantitative data on the distribution of foraminiferal tests revealed three assemblages that depend mainly on the intensity of pollution; (1) a highly polluted tidal flat assemblage, (2) normal (or less polluted) mud flat assemblage and, (3) tidal channel and subtidal assemblage. The highly polluted assemblage characterized by a drop in species densities (< 100 tests/20 cm(3) sediment) but with high average diversity (5.8 Yule-Simpson Index). The microfauna of the less polluted flat displays relatively lower diversity (4.6) but high density of tests (47.2% of the total picked tests). The most abundant species of this assemblage is Ammonia tepida, displays its maximum density in this assemblage. Ammonia tepida drops in density from 17.12% to 3.07% in the polluted assemblage. Tidal channel foraminiferal assemblages should normally display lower diversities than those of tidal flats, because tidal current in the channels tend to wash away most nutrient materials. However, this is not the case of the present study area which could be due to environmental setting of the Sulaibikhat Bay in which tidal currents bring in exceptionally high amounts of nutrients from Shatt Al-Arab Estuary and in which the tidal flats are strongly and adversely polluted. 相似文献
2.
Strategic Environmental Assessment of Plans and Programs: A Methodology for Estimating Effects on Biodiversity 总被引:1,自引:0,他引:1
We developed a methodology for biodiversity evaluations within the process of Strategic Environmental Assessment and we applied
it to the estimation of the effect of two Regional Plans of Development on all bird species inhabiting the Castilla y León
region (northwestern Spain). The methodology is based on the evaluation of the effects of main development actions on the
habitat requirements of species. From these evaluations, and from data on the current distribution and population size (number
of individuals) of each species, we estimated the most likely pattern of distribution and population size after the full implementation
of the plans for each species. The impacts of the plans were quantified as the differences between the pre- and postproject
patterns after codifying them to compensate for differences in the quality of the information available among species. Overall,
we conclude that the proposed methodology fulfills the requirements for its use within the SEA process as it allows for the
assessment of cumulative impacts on every species, highlighting the development directions and the habitat types with major
impacts, and ascertaining whether impacts affect species with either low or high conservation and/or economic value. Generalization
of the proposed methodology to other regions or species will require wildlife-habitat models adequate for SEA analyses, so
that we also propose guidelines for the development and validation of these models. 相似文献
1