Phosphorus Cycling in the Creeping Swamp Floodplain Ecosystem and Exports from the Creeping Swamp Watershed

摘要

Measurement of fluxes to and from a freshwater floodplain swamp ecosystem, Creeping Swamp, NC, and from the surrounding watershed in a North Carolina coastal plain, demonstrated that the swamp floodplain and watershed budget indicated that imports and exports from fertilization and crop harvesting overwhelmed natural imports in precipitation, and exports in surface waters. The lowland location of the swamp floodplain ecosystem regulated the amount and form of phosphorus leaving the watershed in surface waters. Annual rates of exchange of filterable forms of phosphorus are extremely large compared to inputs and available stocks. This suggests that estimations are gross rather than net rates of exchange which was confirmed by comparisons of radiophosphorus-32 dynamics with changes in stable forms of phosphorus.