SGER: The Regulation of Herbivores by the Third Trophic Level: An El Nino Experiment

Coley 98 06674 长期以来，生态学家一直对控制热带森林中食草动物数量的因素感兴趣。 一般认为，食草动物的数量是由食草动物总生物量的限制所控制的，而这些限制又取决于适合作为食物的叶片材料的质量和数量。 然而，该提案的作者认为，食草动物的现存生物量受到较高营养水平控制的影响。 这个项目利用一个不寻常的气候事件来检验这种自上而下控制的假设。 今年即将到来的ENSO事件预计将是一段时间以来最强的一次。 它很可能会导致对食草动物的消费者相对于食草动物本身产生不同压力的条件。 该项目将测试这种影响，以及食草动物的增加，这将是对消费者减少的预测。 它将允许在热带森林中直接测试自上而下的控制假设。

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.