Dynamics of Organization of Insect Communities in Tropical Ecosystems

Abstract

The relatively few studies of tropical ecosystems available have emphasized the pathways of nutrient cycling in some tropical forests⁽⁵⁹⁶⁾ or descriptive and experimental studies of biotic organization of communities. ^(29,65,435) Okwakol⁽⁵⁹⁷⁾ demonstrated in an African termite Cubitermes a relatively high rate of removal of organic materials from soil, suggesting that in habitats where termites are abundant, cyclic depletions of the nutrient content of soil are frequent, thus imposing some constraints upon other litter organisms. To what extent, for example, termites compete with collembolans for certain nutrients under such conditions may indicate food as a hmiting factor in collembolan populations. It is clear, regardless of the interactions, that the litter mosaic of tropical forests is very dynamic in terms of tumover of accessible nutrients and breeding substrates. Historically, much of tropical biology has focused upon expedition-type collecting of specimens for museums and universities, development of cultivars and agronomic systems, and medically related entomology. The entomological literature, for example is full of detailed descriptive and experimental studies on insects as vectors of various tropical diseases and the effects of changing weather pattems on predicting outbreaks. Much of the earlier work in the tropics has deployed a “targeted” approach: in a particular study, an emphasis was placed on few taxa or single species. Surprisingly, a need remains for detailed natural-history studies of tropical organisms to feed the conceptual and theoretical modeling of how communities and whole ecosystems are put together.