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

摘要论文研究：波多黎各热带溪流中洄游生物群的自然和人为景观尺度效应。本论文研究包括三个项目，重点研究宏观消费者（鱼、淡水虾）对波多黎各溪流的景观尺度效应。项目一利用自然实验的优势，考察了上游大坝对生态系统特性的影响，这是由于迁徙的宏观消费者的消失。项目二使用宏观消费者排斥实验来检验小规模操作是否能预测大规模灭绝的影响。项目三是对流经加勒比国家森林的最后一条无水坝干流河流进行纵向调查，并调查宏观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。这三个项目都考察了石屹类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存量。这项研究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尺度，提高我们对水生生物群生态重要性的理解，并记录相对原始的河流条件，从而对热带溪流的保护做出直接贡献。

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.