The commonly observed high diversity of trees in tropical rain forests and corals on tropical
reefs is a nonequilibrium state which, if not disturbed further, will progress toward a low-
diversity equilibrium community. This may not happen if gradual changes in climate favor
different species. If equilibrium is reached, a lesser degree of diversity may be sustained by
niche diversification or by a compensatory mortality that favors inferior competitors.
However, tropical forests and reefs are subject to severe disturbances often enough that …