RECENT PROJECTS
Climate Change, Eutrophication, and Stream Ecosystem Function
Climate change and eutrophication are arguably the greatest threats to ecosystems in our time, yet we have little information on how these processes together will affect ecosystem function. This project uses Iceland's geothermal Hengill valley as a natural experiment to assess these effects on stream productivity and community composition.
Within the small Hengill valley, over 15 streams of different temperatures run within meters of each other and offer an excellent opportunity to look at long term temperature effects. In conjunction with an international collaborative team, we study primary production, nitrogen fixation, nutrient uptake, algal and invertebrate biomass, and isotopic tracing to characterize the streams. In future field seasons we will also be adding N and P to see how streams of different temperatures cope.
More information can be found at the project's blog, Hengill Diaries.
Collaborators: Jon Benstead & Alex Huryn (Univ. Alabama), Jill Welter (Saint Catherine's University), Jim Hood (Ohio State), Jón Ólafsson (Institute of Freshwater Fisheries, Iceland)
Documentary short on our project, by Hans Glassman and Dennis Aig , of MSU's Science and Natural History Filmmaking Program!
Algae, Productivity, and Agriculture
Throughout NW Mississippi, natural waterbodies are manipulated for irrigation water storage. These systems experience extreme daily swings in dissolved oxygen-changes of up to 12 mg/L have been recorded within one day. This project explores the potential effects that frequent, drastic depth changes may have on primary productivity and dissolved oxygen.
Collaborators: Justin Murdock (Tennessee Tech), Richard Lizotte & Martin Locke (USDA ARS National Sedimentation Lab)
Coexistence in Cryptic Amphipod Species Complex
With recent advancements of genetic analyses, many cryptic (phenotypically similar) species have been "discovered." The question then arises of how these extremely similar species co-occur without driving each other to extinction. This study examined the mechanisms maintaining coexistence among undescribed but genetically distinct species of Hyalella azteca.
Collaborators: Rickey Cothran (Southwestern Oklahoma State), Rick Relyea (RPI)