I am interested in the ecology of freshwater ecosystems, including food webs, ecological stoichiometry, nutrient cycling and lake-watershed interactions. I am particularly interested in integrating watersheds and lake ecosystems; the role of animals in recycling and transporting nutrients, both within the context of ecological stoichiometry theory and in terms of impacts at the ecosystem scale; and the interactive effects of light and nutrients on food chain efficiency and biodiversity. My approach includes whole-ecosystem studies, field and lab experiments, and modeling. I am the lead PI on the LTREB project and I oversee aspects of the project related to nutrient cycling, fish abundance and biomass, and phytoplankton. For more information on my research and my lab, please see my lab website.
I am interested in how species interactions can be affected by environmental stresses such as nutrients, sediments, herbicide inputs and exotic species. Within this general framework, I conduct research on pelagic and littoral communities in various aquatic ecosystems such as ponds, reservoirs and the Great Lakes. In the last five year, one of the research goals in my laboratory is to quantify how the efficiency of energy flow through aquatic food chains is constrained by solar radiation (“light”), nutrients, and predators. Our research suggest that light and nutrients, via effects on algal quality, can constrain energy flow through upper trophic levels, i.e., carnivores. Our results from manipulative mesocosm experiments suggest that the nutritional quality of autotrophs can mediate the quality of herbivores as prey for carnivores, i.e., that there is a ‘carryover effect’ of algal quality on herbivore quality. However, predator identity seems to also an important driver regulating the effects of light and nutrients on food chain efficiency and the carryover effects. For our LTREB project, I am responsible for zooplankton and larval fish and their interactions. I have focused on the factors regulating zooplankton communities and how the community responds to changing agricultural practices (e.g., decreased watershed inputs of nutrients, sediments and pesticides). I am also using our LTREB data from Acton Lake to investigate what factors regulate the dynamics of larval gizzard shad, including the timing and size of the hatch, larval survival, and survival of young-of-year fish during their first summer.
My interests are in geomorphology, water resources and environmental management. Most of my recent work has examined the impacts of historic variations in erosion rates on sediment storage and yield, and relations between land use/land management and water quality. I study these issues both at the local (watershed) scale mainly in southwestern Ohio, and at the sub-continental scale and across the United States. Within the LTREB project, I operate gaging stations on three of Acton Lake’s inflow streams, and am responsible for nutrient loading calculations and quantifying trends in stream nutrients.