Record Display for the EPA National Library Catalog


Main Title Persistence in model ecosystems /
Author Gard, T. C.
Publisher U.S. Environmental Protection Agency, Research and Development, Environmental Research Laboratory Center for Environmental Research Information [distributor],
Year Published 1982
Report Number EPA/600-S3-82-030; EPA-600/3 S-82-030
OCLC Number 09121270
Subjects Closed ecological systems--Mathematical models
Internet Access
Description Access URL
Library Call Number Additional Info Location Last
EJBD ARCHIVE EPA 600-S3-82-030 In Binder Headquarters Library/Washington,DC 04/11/2018
EJBD  EPA 600-S3-82-030 In Binder Headquarters Library/Washington,DC 11/14/2018
Collation [2] pages ; 28 cm
Caption title. At head of title: Project summary. "May 1982." "EPA/600-S3-82-030."
Contents Notes
Mathematical models aid in understanding environmental systems and in developing testable hypotheses relevant to the fate and ecological effects of toxic substances in such systems. Within the framework of microcosm or laboratory ecosystem modeling, some differential equation models, in particular, become tractable to mathematical analysis when the focus is on the problem of persistence. In this report, a hierarchy of microcosm-related models, the top level of which contains a nutrient-producer-grazer food chain, and general food chains are analyzed for persistence. The results, which take the form of inequalities involving model parameters, specify necessary conditions and sufficient conditions for continued presence of the model components throughout indefinite time intervals. These results can serve as a basis for preliminary evaluations of model performance.