Organization of instabilities in multispecies systems, a test of hierarchy theory.

The hierarchy theory predicts that system components functioning at lower levels of hierarchy operate or change at higher rates than the components at the level(s) above. If this prediction is correct, then interpretation of stability in complex ecological systems may be in need of revision. We test the prediction using a model of hierarchical structure of habitat and a coral reef fish community. We found that the variability of ecological range and abundance increases exponentially from habitat generalists (high in hierarchy) to specialists (low in hierarchy), as postulated by the hierarchy theory. Our result suggests that community stability is a composite property and should be evaluated by considering the hierarchical structure of that community.