Coley 98 06674 Factors controlling the magnitude of herbivory in tropical forests have been of interest to ecologists for a long time. It has generally been thought that the magnitude of herbivory is controlled by limits on overall herbivore biomass by the quality and quantity of suitable leaf materials for food. The author of this proposal has suggested, however, that the standing biomass of herbivores is influenced by control by higher trophic levels. This project is taking advantage of an unusual climatic event to test this hypothesis of top-down control. This years upcoming ENSO event is anticipated to be the strongest one in some time. It is likely to cause conditions that generate a differential stress on the consumers of herbivores relative to that on the herbivores themselves. This project would test for such an effect and for the increase in herbivores that would be predicted in response to a decline in its consumers. It would allow a direct test of the top-down control hypothesis in tropical forests.
