Tropical Succession: Manifold Routes to Maturity

Abstract

Several characteristics of successional species and communities typical of the lowland, humid tropics are compared with those of drier and colder tropical environments. Suggested trends of successional species characteristics along a gradient from benevolent to harsh tropical environments include: fewer but more specialized taxa; more striking ecological equivalence between biogeographic regions; increased vegetative reproduction; less palatable leaves; denser wood; and decreased importance of chlorophyllous stems. Hypothesized trends of the communities along this same gradient include: slower regrowth; increased resilience (drier sites only); fewer seral stages; and patchier distribution of leaf area. As tropical soils are degraded through misuse, there is a tendency for ruderal vegetation from drier (or colder) environments to invade degraded landscapes in wetter (or warmer) areas. Regrowth and resilience of high-elevation tropical forests are so slow that these communities may never reestablish after clearing. TROPICAL SUCCESSIONAL ECOSYSTEMS conjure up an image of dense tangles of luxurious, impenetrable regrowth: the jungles of popular fiction. However, there are many more combinations of rainfall and temperature regimes in the tropics than in temperate zones. Just as this environmental heterogeneity leads to a broad array of mature ecosystems, it also produces a tremendous variety of successional communi-