Trong thực tế hiện tại, đánh giá rủi ro sinh thái đối với hóa chất độc hại thường được thực hiện trên cơ sở thiết bị đầu cuối vật cá nhân như sự sống còn, tăng trưởng, hoặc các biện pháp sinh sản. Thừa nhận những hạn chế của phương pháp này, nhiều nhà sinh thái học ủng hộ việc sử dụng dân số và mô hình hóa hệ sinh thái để đánh giá rủi ro của các hóa chất độc hại. Các mô hình này được sử dụng để dịch các kết quả của đặc tính rủi ro đối. | CHAPTER 16 Summary Robert A. Pastorok and H. Resit Akẹakaya In current practice ecological risk assessments for toxic chemicals are typically made on the basis of individual-organism endpoints such as survival growth or reproductive measures. Recognizing the limitations of this approach many ecologists advocate the use of population and ecosystem modeling for assessing risks of toxic chemicals. Such models are used to translate the results of risk characterization for individual-organism endpoints into estimates of effects on population ecosystem and landscape endpoints. These ecological endpoints include species richness population abundance or biomass population growth rate or reproductive output population age structure and productivity. We report here the results of a critical evaluation of ecological-effects models that are potentially useful for chemical risk assessment. After candidate models were compiled they were classified as toxicity-extrapolation population ecosystem or landscape models. Toxicity-extrapolation models are simple empirical sometimes statistical means of extrapolating toxicity thresholds or of ordering species sensitivity to toxic chemicals. Population models typically deal with the dynamics of the abundance or distribution of single species and sometimes with explicit descriptions of endpoints in time and space. Ecosystem models are mathematical expressions that are intended to describe ecological systems composed of interacting species food webs with or without abiotic environmental factors. Spatially explicit multispecies models which generally include abiotic factors were defined as landscape models whereas spatially explicit models of single-species populations were defined as metapopulation models. Other model types and formulations that might be defined by others as ecological models were excluded from the initial compilation because they did not predict relevant ecological endpoints or because they addressed spatial or temporal .
