Research in my lab focuses on nutrient cycling in freshwater wetland and terrestrial forest ecosystems. My group is currently working in a network of 12 forested floodplains in the southeastern U.S., that vary in floodplain type (alluvial vs. blackwater) and underlying parent material (young Pliocene/Miocene vs. older Cretaceous sediments). Preliminary studies suggest that both factors are important in determining whether nitrogen (N) or phosphorus (P) limits plant growth in these ecosystems, but that floodplain type determines the quantity and quality of soil organic P that accumulates. Current investigations are examining how these factors affect: 1) the physical and chemical characteristics associated with soil P retention (P sorption capacity); 2) P transformation processes occurring during late winter/early spring flooding, including interactions with carbon, N, aluminum, and iron; 3) the composition and function of soil microbial communities using molecular techniques; and 4) stand level nutrient cycling (e.g., foliar nutrient allocation; nutrient return in litterfall).

Dr. Walbridge's Home Page: http://www.as.wvu.edu/walbridge