Tri-Service Remedial Project Manager's Guide for Ecological Risk ...

Trophic Level: 5 A functional classification of taxa within a community that is based on feedingrelationships (e.g., green plants make up the first trophic level, plant-eating animals make up thesecond, primary meat-eaters make up the third, animals that eat them make up the fourth, and soon). Note: 4 This trophic classification is one of function and not of species; a given speciespopulation may occupy one or more trophic levels according to the source of energy assimilated.Uncertainty: 2 Imperfect knowledge concerning the present or future state of the system underconsideration; a component of risk resulting from imperfect knowledge of the degree of hazard orof its pattern in space and time.Uncertainty Factor: 2 A factor applied to an exposure or effects concentration or dose to correctfor identified sources of uncertainty.1U.S. EPA. 1997. Ecological Risk Assessment Guidance for Superfund: Process forDesigning and Conducting Ecological Risk Assessments. Interim Final, EPA 540-R-97-006; OSWER 9285.7-25; PB97-963211. U.S. Environmental Protection AgencyEnvironmental Response Team, Edison, NJ.2Suter, G.W., II. 1993. Ecological Risk Assessment. Lewis Publishers, Boca Raton, FL.538 p.3Environment Canada. 1997. Environmental Assessments of Priority Substances Under theCanadian Environmental Protection Act. Guidance Manual Version 1.0, EPS/2/CC/3E,Chemicals Evaluation Division, Commercial Chemicals Evaluation Branch, Environment Canada,Ottawa, Ontario, Canada.4Daubenmire, R.F. 1974. Plants and Environment, a Textbook of Autecology. John Wiley andSons, New York.5 U.S. EPA. 1998. Guidelines for Ecological Risk Assessment. EPA/630/R-95/002F. U.S.Environmental Protection Agency. Washington, D.C.Key Terms - 8