Phosphorus enrichment of marsh soils can act as an internal source of nutrients to the water column, continuing to drive existing wetland eutrophic conditions even after external sources have been terminated. The goal of this study were to determine the effects of soil P concentration and flood intolerant vegetation presence on initial (1–10 d) and extended (10–38 d) P release rates from the soils after reflooding. Intact soil cores were collected from P enriched and unenriched areas of the Blue Cypress Marsh in east‐central Florida. Initial P release was greater in soils with higher soil total P concentrations and containing vegetation. Soil P enrichment resulted in the final water column P concentrations in the enriched cores to be 50% higher than those in the P unenriched cores. A single drawdown and reflood event led to ∼6% of the total soil P released to the water column from the P enriched vegetated treatment compared with a ∼1% of total P released from the P enriched non‐vegetated treatment. Initial P release rates from the enriched, vegetated treatment were five times greater than the enriched, non‐vegetated treatment. Episodic growth of flood intolerant plants under drawdown conditions was shown to be a significant mechanism for nutrient release in ephemerally flooded P enriched wetland systems. Episodic flooding and drying cycles could therefore mobilize P over the long‐term from P enriched to P unenriched areas.

All rights reserved. No part of this periodical may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or any information storage and retrieval system, without permission in writing from the publisher. Permission for printing and for reprinting the material contained herein has been obtained by the publisher. Redistribution of Wetland Soil Phosphorus Ten Years after the Conclusion of Nutrient Loading Wetland Soils N utrient enrichment from agricultural and municipal runoff can result in fundamental changes to soil biogeochemistry, water quality, and composition of plant communities in wetland systems (DeBusk and Reddy, 1998; Newman et al., 1997; Reddy et al., 1998). Nutrient loading to wetland systems can result in the formation of soil nutrient gradients emanating from the infl ow points and extending outward based on hydrologic fl ow patterns and surface topography (