'Stream signatures' and aquatic-terrestrial interactions in arthropod food webs.

摘要

The focus of this dissertation is on ecological subsidies, or the transmission of energy, carbon, and nutrients from one ecosystem to another. Specifically, the four individual research projects that form this dissertation are all focused on subsidies from streams and rivers to recipient arthropod food webs in terrestrial landscapes. The first chapter of this dissertation provides a theoretical basis for a suite of variables that can affect the transmission of this subsidy, and comments on areas where the theory supporting a given variable is weak and may warrant further investigation. The second chapter uses a meta-analysis of the existing literature on the spatially-explicit dynamics of river-land subsidies to derive "stream signatures" that highlight the distance that these subsidies can penetrate into the terrestrial landscape. In the third chapter, field data from a multi-continent study are used to explore the hydrogeomorphic and vegetation conditions that affect the stream signature. Finally, the fourth chapter of this dissertation uses a flood in a unique river ecosystem to explore how patterns of succession and island biogeographical processes interact to affect aquatic and terrestrial arthropod community recovery in a highly subsidy-dependent ecosystem after a large flash flood disturbance. Overall, this dissertation greatly improves the existing body of literature on the distance that aquatic subsidies can travel from streams and rivers to land, and the conditions that affect the transmission of these resources to recipient terrestrial food webs.