Wilder Lab
Trophic Ecology and Nutrition
Department of Integrative Biology, Oklahoma State University
Trophic Interactions in Arthropod Food Webs
Much of the current research in my lab focuses on trophic interactions and their consequences for consumers and food webs. A long term goal of this work is to understand how the nature of individual feeding interactions scale to affect the dynamics of food webs and ecosystems. To do so, we need to better integrate individual-level foraging and digestive physiology, with population and community ecology, and flows of nutrients through ecosystems. Much of my past and current work in this area has examined how predators extract nutrients from prey, the consequences of prey nutrient content for predator growth, and the implications of nutrition for food webs.
One component of this research program is understanding what nutrients predators extract from their prey. I'm especially interested in arthropod predator-prey interactions as arthropods are abundant and diverse animals that can have large effects on trophic dynamics in many ecosystems. Arthropods are also interesting to study because they are composed of several major pools of nutrients that likely differ widely in digestibility for predators, which complicates the study of nutrient transfers. We are currently testing if common methods for studying nutrient transfers and flows in food webs and ecosystems, namely the study of elements, is a reliable predictor of the amount of nutrients consumed by predators when they feed on prey. Our preliminary work suggests that measuring the total carbon and nitrogen content of prey can overestimate the amount of carbon and nitrogen that is actually ingested and assimilated by predators when they feed on those prey. This is because significant amounts of carbon and nitrogen are found in the indigestible exoskeleton of arthropods and because the amount of exoskeleton in insects can vary widely among species.
Given that different types of invertebrate prey can vary in quality for carnivores, changes in arthropod community composition could have important implications for carnivores. We've recently been examining how land management techniques, such as prescribed fire and discing, affect arthropod communities in Western Oklahoma. Land management is used on Wildlife Management Areas in Oklahoma to increase the quality of habitat for game species. We're interested in testing how these management techniques affect the abundance and nutritional quality of insects that may be fed upon by bobwhite quail chicks.
We have also begun studying the role of spiders in regulating the flow of nutrients through ecosystems. In collaboration with Dr. Dror Hawlena (The Hebrew University of Jerusalem, Israel), we are testing if spiders concentrate nutrients from uneaten parts of prey carcasses and excreta under their webs and if these nutrient deposits affect soil microbial processes and plant growth.
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While much of the research in my lab has involved carnivores, we've also begun studying plant-herbivore interactions. We're especially interested in understanding how inorganic nutrients in the soil are converted to organic nutrients in plants and how the balance of inorganic and organic nutrients in plant tissue affects the success of herbivores and the flow of nutrients through ecosystems.