Cách tiếp cận chung là để bước đầu xác định một loạt các mô hình sử dụng tiềm năng trong việc đánh giá rủi ro sinh thái, thu hẹp danh sách này trên cơ sở các tiêu chí như khả năng sử dụng và phù hợp, và sau đó tiến hành đánh giá chi tiết hơn về các mô hình triển vọng nhất (Hình ). Vì vậy, một quy trình hai bước đánh giá được sử dụng. Bước đầu tiên là một phân tích đơn giản để xác định các mô hình đáp ứng yêu cầu tối thiểu. Bước. | CHAPTER 2 Methods Robert A. Pastorok and H. Resit Akẹakaya The general approach is to initially identify a variety of models for potential use in ecological risk assessment to narrow this list on the basis of criteria such as usability and relevance and then to conduct a more detailed evaluation of the most promising models Figure . Thus a two-step evaluation procedure is used. The first step is a simple analysis to identify models that meet minimum requirements. The second step is a detailed evaluation of models that pass the first step. COMPILATION AND REVIEW OF MODELS Models that have been applied to ecological risk assessments for aquatic and terrestrial habitats are considered in our review. Basic ecological models used to describe populations ecosystems or landscapes are also included even if others do not currently consider them for use in ecological risk assessment. Both mathematical formulations that comprise the models themselves and selected software packages used to implement them . VORTEX by Lacy 1993 ULM by Legendre and Clobert 1995 are considered. Although our review emphasizes user-friendly software environments that are designed to support population and ecosystem modeling generalized modeling software such as STELLA High Performance Systems 2001 ModelMaker ModelKinetix 2001 and MATLAB MathWorks 2001 can be used to implement all model types discussed herein. Compilation and Classification of Models Ecological-effects models were identified through literature searches personal contacts with scientists involved with ecological modeling and a review of model compilations . Morrison et al. 1992 J0rgensen et al. 1996 SAIC 1996 Hilborne and Mangel 1997 ANL 1998 ORNL 1998 . A search over the Internet was conducted including a search of the database on ecological models maintained by the University of Kassel in Germany http model_db and other web sites with general information on ecological modeling Table .
