Operation of a Trophic Cascade in Predator-free Forest Fragments

捕食在调节陆地生态系统中的作用，以及陆地生态系统是否受到强烈的营养级联(从捕食者通过草食动物流向植物的影响)的相关问题是当前生态学辩论的主题。这项拟议中的研究利用了一项耗资数十亿美元的“实验”，该实验在委内瑞拉一个4300平方公里的蓄水池中创建了大量无捕食者的岛屿，与委内瑞拉的一个水电设施有关。这项拟议的研究大体上检验了这样一种假设，即岛屿的无捕食者状态最初应该导致草食动物(以种子和树叶为食的物种)的高度丰富，然后作为营养级联的结果对植被造成巨大影响。主要活动包括继续在实验岛屿上清除啮齿动物和蚂蚁的计划，以及重新审查植物地块，以记录未经处理和处理的岛屿上植被变化的动态。这项研究可能为大型捕食者在热带森林中扮演的重要功能角色提供了迄今最直接的联系。这对保护有巨大的影响，因为人类造成的热带森林捕食者的丧失可能会极大地改变热带森林的植物物种组成，导致多样性的显着下降。

The role of predation in regulating terrestrial ecosystems, and the related question of whether terrestrial ecosystems are subject to strong trophic cascades (effects which flow from predators through herbivores to plants) are topics of current debate in ecology. The proposed research takes advantage of a multi-billion dollar "experiment" that has created a large number of predator-free islands in a 4,300 square-kilometer impoundment associated with a hydroelectric installation in Venezuela. The proposed research generally tests the hypothesis that the predator-free status of islands should lead initially to a hyper-abundance of herbivores (seed and leaf eating species), and then to massive impacts on the vegetation as a consequence of trophic cascades. Primary activities include continuing rodent and ant removal programs on experimental islands and re-censusing plant plots to record the dynamics of vegetation change on both untreated and treated islands. This research may provide the most direct link yet to the important functional role played by large predators in tropical forests. This has enormous implications for conservation because human-induced loss of predators from tropical forests may drastically alter plant species composition of tropical forests resulting in significant declines in diversity.