PARENT SESSION
Oral Session #9: Trophic structure and community interactions. Presiding: B. Menge.
Monday, August 6, 2001. 8:00 AM to 11:45 AM. Hall of Ideas I.
Estimating community stability and ecological interactions from time-series data.
Ives, Anthony1, Dennis, Brian2, Cottingham, Kathryn3, Carpenter, Stephen1, 1 2 3
ABSTRACT- Natural ecological communities are continuously buffeted by a varying environment, making it difficult to measure the stability of communities using concepts requiring the existence of an equilibrium point. Instead of an equilibrium point, the equilibrial state of communities subject to environmental stochasticity is a stationary distribution, which is characterized by means, variances, and other statistical moments. We derive properties of the stationary distribution of multispecies communities that measure different characteristics associated with community stability. These properties can be estimated from multispecies time-series data using first-order multivariate autoregressive (MAR(1)) models. To illustrate these methods, we compare the stability of the planktonic communities in three lakes in which nutrient loading and planktivorous fish abundance were experimentally manipulated. MAR(1) models and the stability measures we derive can be of general use in comparing the stability properties of naturally varying communities.
KEY WORDS: community stability, resilience, time-series analysis