Dissertation Research: Effects of Large Terrestrial Carnivores in Insular Ecosystems

9700942舍纳生态学中的一个主要问题是顶级捕食者如何影响其他营养水平。虽然许多野外实验研究都是为了了解食物网是如何发挥作用的，但很少有研究包括非常大型的陆生食肉动物。其中一个原因可能是，在有限的、定义明确的地点操纵这种捕食者普遍存在困难。澳大利亚大堡礁的某些岛屿提供了一个在一个系统上进行实地实验的机会，这个系统包含一种非常大的陆地食肉动物--巨蜥，它很容易被观察和操作。监测蜥蜴和次低营养水平的较小的尖吻蜥蜴，将被排除在交叉设计的实验区之外。在实验开始后，将定期记录骨节肢动物和落叶节肢动物的密度和分类组成等变量。为了补充实验研究，将在有和没有监测蜥蜴自然存在的岛屿上进行石龙骨和节肢动物密度以及分类组成的比较。这项研究将有助于填补我们在生态学知识中关于大型食肉动物在食物网中的重要性的主要空白。

9700942 Schoener A primary question in ecology is how a top predator affects other trophic levels. While many field-experimental studies have been directed toward understanding how food webs function, few have included very large terrestrial carnivores. One reason may be the general difficulty of manipulating such predators in limited, well-defined sites. Certain islands of Australia's Great Barrier Reef provide an opportunity to conduct field experiments on a system which contains a kind of very large terrestrial carnivore, monitor lizards, that is easily observed and handled. Monitor lizards and the next-lowest trophic level, the smaller scincid lizards, will be excluded or not from experimental plots in a crossed design. Skink and leaf-litter arthropod densities and taxonomic compositions, among other variables, will be recorded at regular intervals after inception of the experiment. To complement the experimental study, a comparison of skink and arthropod densities and taxonomic compositions will be performed on islands with and without monitor lizards naturally present. This study will help begin to fill the major gap in our ecological knowledge concerning the importance of very large carnivores in food webs.