This award provides partial support for a long-term research visit to Denmark by Dr. James T. Morris of the University of South Carolina. He will collaborate with Dr. Arne Jensen and others of the Botanical Institute of the University of Aarhus in a comparative study of salt marsh carbon cycles. Dr. Morris has studied carbon dioxide exchange, decomposition and nutrient uptake in marshes for many years, and has produced several physiologically based models of these processes. With Dr. Jensen, he will adapt these models to Skallingen salt marsh in Denmark, and use the models to explore differences in the carbon cycles of climatically dissimilar marshes from Northern Europe and the Southeastern United States. They also plan to combine these models into an integrated ecosystem level model that will be used to predict the dynamics of salt marsh carbon cycles, including below- ground production. The collaborative plan provides Dr. Morris with access to a vastly different marsh environment, an excellent group of plant ecologists, led by Dr. Jensen, and a world renowned group of estuarine biogeochemists. He expects to learn remote sensing skills and new methods in plant physiology, as well as benefit from the different concepts and approaches to ecology in Europe. In return, the Danish group should benefit from Dr. Morris'expertise in numerical modelling. Salt marshes are highly productive ecosystems that exist worldwide along continental margins in the temperate zone. Primary production in these ecosystems is thought to be an important source of nutrition for commercially important fishes. Salt marshes also function as sinks for organic carbon; however, knowledge of the carbon cycle in salt marshes is incomplete. The rate of below-ground primary production has been especially difficult to measure and is subject to great uncertainty due to sampling error. The proposed collaboration is expected to result in a theoretically robust model that will be useful for predicting or evaluating primary production and other carbon cycle processes in salt marshes. The structure of the model is general and could be applied to other systems when calibrated.
