Control Processes in a Terrestrial Food Web: Trophic Interactions of a Generalist Predator

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The proposed research will investigate top-down and bottom-up control processes in a poorly understood but critical terrestrial food web: the detritus-based web of the forest floor. The wolf spider Schizocosa oreata, an abundant generalist predator, occupies an intermediate position in food webs of the leaf-litter community of deciduous forests throughout eastern North America. This project investigates control processes in this food web using laboratory experiments and a series of short-term and long term manipulative field experiments designed to reveal how S. oreata interacts with trophic levels above and below it. %%% Understanding how food webs function is critical to prudent management and conservation of ecological communities. Current food-web theory focuses on how resource limitation and predator- prey interactions affect species on different trophic levels. Densities of species at intermediate trophic levels may be sensitive to cascading effects of top predators, or top-down control, and also may respond to changes in resource levels at the bottom of the food web, or bottom control. The results will be broadly applicable because spiders are major predators in all terrestrial habitats, and because processes within the forest-floor food web are critical to energy flow and nutrient cycling in forest ecosystems.