tailieunhanh - ECOTOXICOLOGY: A Comprehensive Treatment - Chapter 22

Biomonitoring được định nghĩa là việc sử dụng các hệ thống sinh học để đánh giá tính toàn vẹn về cấu trúc và chức năng của hệ sinh thái trên cạn và thủy sản. Karr và Dudley (1981) xác định tính toàn vẹn sinh học như khả năng của một hệ sinh thái "để hỗ trợ và duy trì một cân bằng, tích hợp, cộng đồng và thích nghi của sinh vật có một thành phần loài, đa dạng, và các cơ quan chức năng so sánh được với môi trường sống tự nhiên trong khu vực.". | 22 Biomonitoring and the Responses of Communities to Contaminants BIOMONITORING AND BIOLOGICAL INTEGRITY Biomonitoring is defined as the use of biological systems to assess the structural and functional integrity of aquatic and terrestrial ecosystems. Karr and Dudley 1981 define biological integrity as the ability of an ecosystem to support and maintain a balanced integrated adaptive community of organisms having a species composition diversity and functional organization comparable to natural habitats in the region. Measurements endpoints used to assess biological integrity may be selected from any level of biological organization however the historical focus has been on populations communities and ecosystems. Community-level biological monitoring which is the focus of this chapter is based on the assumption that composition and organization of communities reflect local environmental conditions and respond to anthropogenic alteration of those conditions. A second important assumption of community-level biomonitoring is that species differ in their sensitivity to anthropogenic stressors resulting in structural and functional changes at polluted sites. Karr and Dudley s definition of biological integrity underscores the two most significant challenges to the development and implementation of community-level monitoring the selection of endpoints and the identification of reference conditions. Although Karr and Dudley provide some suggestions for endpoints . species diversity and composition there is little consensus among ecologists as to what key features of communities are the most appropriate indicators of biological integrity. There is however widespread agreement that no single measure will be effective and that approaches integrating several endpoints are often necessary to assess effects of contaminants. The selection of appropriate reference sites and the determination of what exactly constitutes natural habitats in the region have been equally .