Campus Units

Botany

Document Type

Article

Publication Version

Published Version

Publication Date

9-1998

Journal or Book Title

The American Naturalist

Volume

152

Issue

3

First Page

321

Last Page

337

DOI

10.1086/286172

Abstract

We used auto- and cross-correlation analysis and Ripley’s K-function analysis to analyze spatiotemporal pattern evolution in a spatially explicit simulation model of a semiarid shrubland (Karoo, South Africa) and to determine the impact of small-scale disturbances on system dynamics. Without disturbance, local dynamics were driven by a pattern of cyclic succession, where ‘‘colonizer’’ and ‘‘successor’’ species alternately replaced each other. This results in a strong pattern of negative correlation in the temporal distribution of colonizer and successor species. As disturbance rates were increased, the relationship shifted from being negatively correlated in time to being positively correlated—the dynamics became decoupled from the ecologically driven cyclic succession and were increasingly influenced by abiotic factors (e.g., rainfall events). Further analysis of the spatial relationships among colonizer and successor species showed that, without disturbance, periods of attraction and repulsion between colonizer and successor species alternate cyclically at intermediate spatial scales. This was due to the spatial ‘‘memory’’ embedded in the system through the process of cyclic succession. With the addition of disturbance, this pattern breaks down, although there is some indication of increasing ecological organization at broader spatial scales. We suggest that many of the insights that can be gained through spatially explicit models will only be obtained through a direct analysis of the spatial patterns produced.

Comments

This article is from The American Naturalist 152 (1998): 321, doi: 10.1086/286172. Posted with permission.

Copyright Owner

The University of Chicago

Language

en

File Format

application/pdf

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