title: Spatial scaling in a benthic population model with density-dependent disturbance.
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.
authors.affiliation: Center of Marine Biotechnology, University of Maryland Biotechnology Institute, Baltimore, Maryland 21202, USA.
authors.forename: M
authors.initials: M
authors.lastname: Pascual
authors.forename: S A
authors.initials: SA
authors.lastname: Levin
mesh_terms: D000367:Age Factors; D000704:Analysis of Variance; D000818:Animals; D015982:Bias; D049872:Bivalvia / Q000502:physiology; D003441:Crowding; D003627:Data Interpretation, Statistical; D008386:Marine Biology; D015233:Models, Statistical; D009026:Mortality; D017711:Nonlinear Dynamics; D009792:Oceans and Seas; D011156:Population Density; D015203:Reproducibility of Results; D013269:Stochastic Processes