Tuesday, November 14, 2006 - 9:30 AM
209-1

Phosphorus Memory in Wetlands and Aquatic Systems: Implications to Ecosystem Restoration.

K. R. Reddy, Univ of Florida, Soil & Water Science Dept, 106 Newell Hall, PO Box 110510, Gainesville, FL 32611

Wetlands and aquatic systems such as lakes are often the final recipients of nutrients discharged from adjacent terrestrial ecosystems. Since many freshwater systems are phosphorus (P) limited, loading of this nutrient is of particular concern to environmental managers. Nonpoint sources of P dominate eutrophication processes of many wetlands and aquatic ecosystems. Thus, in many situations, alternative land use management practices in the watershed are implemented in an effort to reduce the overall load to receiving water bodies.  The key questions often asked are: (i) will wetlands and aquatic systems respond to P load reduction?; (ii)  if so, how long will it take for these systems to recover and reach its background condition?; (iii) what biogeochemical processes regulate the mobilization of internally stored phosphorus; and (iv) are there any economically feasible management options to hasten the recovery process?  Once the external P loads are reduced, the internal memory of P can extend the time required for a wetland or an aquatic system to recover from eutrophic status to more background levels.  The lag time for recovery should be considered in developing management strategies to restore wetlands and aquatic systems.  This presentation will include a discussion on a range of biogeochemical and hydrodynamic processes regulating the mobilization of P stored within the system.