Species Diversity and Abundance in Insular Systems

将继续研究亚热带岛屿生态系统中生态相互作用的重要性和机制。对大型围栏中的蜥蜴、蛛网蜘蛛或两者都不移除的实验将确定蜥蜴和蜘蛛对周围昆虫和树叶损害的单独影响，以及蜘蛛数量的增加是否补偿了蜥蜴的移除。蜥蜴如何减少蜘蛛对猎物的摄取，将通过监测陷阱中的猎物、网中的猎物和实际摄取的猎物；通过观察白天和夜间的消耗；通过测试蜘蛛是否在没有蜥蜴的围栏中使用更有生产力的场所来确定。自然网中的食物水平将提高到无蜥蜴围栏的水平，以观察对蜘蛛繁殖力的影响。将在无蜥蜴的小岛上引入蜥蜴，以测量对周围昆虫和树叶损害的影响，并通过与邻近的蜥蜴岛进行比较，测试该实验最终是否能模拟自然情况。将对100多个岛屿上的约250只蜘蛛和约35只蜥蜴进行监测，以确定灭绝的原因、长期种群稳定和正在进行的竞争实验的结果。一个总的前提是使用岛屿作为了解社区和生态系统过程的模式。

Research on the importance and mechanisms of ecological interactions, as exemplified in subtropical island ecosystems will be continued. An experiment with lizards, web spiders, both, or neither removed from large enclosures will determine the separate effects of lizards and spiders on ambient insects and foliage damage, as well as whether an increase in spiders compensates for lizard removal. How lizards reduce prey consumption by spiders will be determined by monitoring prey in traps, prey in webs and prey actually consumed; by observing diurnal versus nocturnal consumption; and by testing whether spiders use more productive sites in no-lizard enclosures. Food levels in natural webs will be raised to those of no-lizard enclosures to see the effect on spider fecundity. Lizards will be introduced onto no-lizard islets to measure effects on ambient insects and foliage damage, and by comparison with adjacent lizard islands, tests will be made of whether the experiment can eventually mimic the natural situation. About 250 spider and about 35 lizard populations will be monitored on over 100 islands to determine causes of extinction, long-term population stability and results of ongoing competition experiments. An overall premise is the use of islands as a model for understanding community and ecosystem processes.