DISSERTATION RESEARCH: Natural and Human-generated Landscape Scale Effects of Migratory Biota in Tropical Streams, Puerto Rico

摘要散布研究：热带河流迁徙生物群的自然和人为景观尺度效应，波多黎各DEB-0308543本论文研究由三个项目组成，重点是大消费者(鱼、淡水虾)对波多黎各河流的景观尺度效应。项目一利用一项自然实验，考察了由于迁徙的大消费者的灭绝，大坝对生态系统特性的上游影响。项目二使用宏观消费者排斥实验来检验小规模的操纵是否可以预测大规模剔除的效果。项目三是对排干加勒比国家森林的最后一条未筑坝的干流进行纵向调查，调查大消费者分布的自然变化以及河流连续体概念与热带岛屿的相关性。所有这三个项目都检查了表层的细颗粒和粗颗粒有机物、细颗粒无机物以及藻类和昆虫生物量的现存量。这项研究的更广泛的意义包括通过将小规模实验外推到人类影响流域的更大规模，提高我们对水生生物群的生态重要性的理解，以及记录相对原始的河流状况，从而直接促进热带河流的保护。

AbstractDISSERTATION RESEARCH: Natural and Human-generated Landscape Scale Effects of Migratory Biota in Tropical Streams, Puerto RicoPringle DEB-0308543This dissertation research consists of three projects focusing on landscape-scale effects of macroconsumers (fish, freshwater shrimp) on Puerto Rico streams. Project one takes advantage of a natural experiment and examines upstream effects of dams on ecosystem properties due to extirpation of migratory macroconsumers. Project two uses macroconsumer exclusion experiments to examine whether small-scale manipulations predict effects of large-scale extirpation. Project three is a longitudinal survey of the last undammed main stem river draining the Caribbean National Forest and investigates natural variation in macroconsumer distributions and the relevance of the River Continuum Concept to tropical islands. All three projects examine standing stocks of epilithic fine and coarse particulate organic matter, fine particulate inorganic matter, and algal and insect biomass. The broader significance of this research includes direct contributions to conservation of tropical streams by extrapolating small-scale experiments to the larger scales at which humans affect watersheds, improving our understanding of the ecological importance of aquatic biota and documenting relatively pristine river conditions.