(1) Environmental Sciences Division, Savannah River Laboratory, Savannah River Site, 29808-0001 Aiken, South Carolina, USA;(2) Department of Statistics, Virginia Polytechnic Institute and State University, 24061 Blacksburg, Virginia, USA
Abstract:
This paper presents a dynamic framework for environmental assessment when the system under study is undergoing successional
change. Successional differences between sites for which one wishes to detect a difference because of a treatment are essentially
confounding factors. We show how successional changes over the study period or resulting from differences in study site plot
ages can be factored out by developing a null model of expected behavior over time. The null model for change in state with
time is characterized in terms of a stochastic envelope around a nominal trajectory. Specific tests for the detection of trends
associated with succession are described and illustrated on example data. It is concluded that the methods developed work
particularly well for laboratory microcosm data.