Spatial scaling in a benthic population model with density-dependent disturbance

Authored by Simon A Levin, M Pascual

Date Published: 1999

DOI: 10.1006/tpbi.1999.1417

Sponsors: United States National Aeronautics and Space Administration (NASA) United States Office of Naval Research (ONR) Alfred P. Sloan Foundation

Platforms: No platforms listed

Model Documentation: Other Narrative Mathematical description

Model Code URLs: Model code not found

Abstract

This work investigates approaches to simplifying individual-based models in which the rate of disturbance depends on local densities. To this purpose, an individual-based model for a benthic population is developed that is both spatial and stochastic. With this model, three possible ways of approximating the dynamics of mean numbers are examined: a mean-field approximation that ignores space completely, a second-order approximation that represents spatial variation in terms of variances and covariances, and a patch-based approximation that retains information about the age structure of the patch population, Results show that space is important and that a temporal model relying on mean disturbance rates provides a poor approximation to the dynamics of mean numbers. It is possible, however, to represent relevant spatial variation with second-order moments, particularly when recruitment rates are low and/or when disturbances are large and weak. Even better approximations are obtained by retaining patch age information. (C) 1999 Academic Press.

Tags

Dynamics ecosystems Community ecology pattern Recruitment Environments Intertidal zone