Community extinction patterns in coloured environments.
Understanding community responses to environmental variation is a fundamental aspect of ecological research, with direct ecological, conservation and economic implications. Here, we examined the role of the magnitude, correlation and autocorrelation structures of environmental variation on species' extinction risk (ER), and the probability of actual extinction events in model competitive communities. Both ER and probability increased with increasing positive autocorrelation when species responded independently to the environment, yet both decreased with a strong correlation between species-specific responses. These results are framed in terms of the synchrony between--and magnitude of variation within--species population sizes and are explained in terms of differences in noise amplification under different conditions. The simulation results are robust to changes in the strength of interspecific density dependence, and whether noise affects density-independent or density-dependent population processes. Similar patterns arose under different ranges of noise severity when these different model assumptions were examined. We compared our results with those from an analytically derived solution, which failed to capture many features of the simulation results.
Ruokolainen
Lasse
L
Department of Ecology and Evolutionary Biology, Faculty of Biological and Environmental Sciences, Helsinki University, PO Box 65, Viikinkaari 1, 00014 Helsinki, Finland. lasse.ruokolainen@helsinki.fi
Fowler
Mike S
MS
D000818:Animals; D003198:Computer Simulation; D017753:Ecosystem; D053476:Extinction, Biological; D008954:Models, Biological; D011157:Population Dynamics