Forms, amounts and accumulation rates of phosphorus were measured in marshes surrounding Upper Klamath Lake, Oregon to assess the potential of marsh restoration to sequester P and improve water quality. Soil cores collected from three natural and three marshes being restored were analyzed to determine the forms and amounts of soil P. Soil cores from the natural marshes were radiometrically dated to determine rates of peat accretion and P accumulation. Soil P was more than 2 times greater in the restoration marshes compared to the natural marshes as a result of greater bulk density. More than 66% of the P pool in both the natural and restoration marshes was present in recalcitrant forms providing long-term P storage in peat. Phosphorus accumulation in the natural marshes averaged 0.45 g m-2 yr-1 (137Cs) and 0.40 g m-2 yr-1 (210Pb). Assuming the restoration marshes will sequester P at comparable rates after reflooding, the 5,800 ha of marsh being restored has the potential to reduce P loading to the lake by approximately 26 t yr-1. Effective P sequestration in the restoration marshes, however, will depend on re-establishing equilibrium between the P enriched soils and P concentration of floodwaters and a hydrologic regime similar to the natural marshes.

Recent Publications

Aldous, A., P. McCormick, C. Ferguson, S. Graham, and C. Craft. 2005.Hydrologic
 regime Controls Soil Phosphorus Fluxes in Restoration and Undisturbed wetlands.
Restoration Ecology. 13: 341-347.