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publications > paper > short-term changes in phosphorus storage in an oligotrophic Everglades wetland ecosystem receiving experimental nutrient enrichment
Short-term changes in phosphorus storage in an oligotrophic Everglades wetland ecosystem receiving experimental nutrient enrichment
Gregory B. Noe1,*, Daniel L. Childers1,2, Adrienne L. Edwards1,4, Evelyn Gaiser1, Krish Jayachandran1,3, David Lee2, John Meeder1,3, Jennifer Richards2, Leonard J. Scinto1, Joel C. Trexler2 & Ronald D. Jones1,2
1Southeast Environmental Research Center; 2Department of Biological Sciences;
3Department of Environmental Studies, Florida International University, Miami, FL 33199,
U.S.A.; 4Present address: Illinois Natural History Survey, 607 East Peabody Drive,
Champaign, IL 61820, U.S.A. (*author for correspondence, e-mail: noeg@fiu.edu)
Abstract
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| Figure 5. Phosphorus standing stocks (mean ± one s.e.) in different ecosystem components at different distances down-flume in response to P enrichment. [larger version] |
Natural, unenriched Everglades wetlands are known to be limited by phosphorus (P) and responsive to P enrichment. However, whole-ecosystem evaluations of experimental
P additions are rare in Everglades or other wetlands. We tested the response of the Everglades
wetland ecosystem to continuous, low-level additions of P (0, 5, 15, and 30 µg L-1 above
ambient) in replicate, 100 m flow-through flumes located in unenriched Everglades National
Park. After the first six months of dosing, the concentration and standing stock of phosphorus
increased in the surface water, periphyton, and flocculent detrital layer, but not in the soil
or macrophytes. Of the ecosystem components measured, total P concentration increased the
most in the floating periphyton mat (30 µg L-1: mean = 1916 µg P g-1, control: mean = 149 µg P g-1), while the flocculent detrital layer stored most of the accumulated P (30 µg L-1: mean = 1.732 g P m-2, control: mean = 0.769 g P m-2). Significant short-term responses of P concentration and standing stock were observed primarily in the high dose (30 µg L-1 above ambient) treatment. In addition, the biomass and estimated P standing stock of aquatic consumers increased in the 30 and 5 µg L-1 treatments. Alterations in P concentration and
standing stock occurred only at the upstream ends of the flumes nearest to the point source of
added nutrient. The total amount of P stored by the ecosystem within the flume increased with
P dosing, although the ecosystem in the flumes retained only a small proportion of the P added
over the first six months. These results indicate that oligotrophic Everglades wetlands respond
rapidly to short-term, low-level P enrichment, and the initial response is most noticeable in the
periphyton and flocculent detrital layer.
Related information:
SOFIA Project: Effect of Water Flow on Transport of Solutes, Suspended Particles, and Particle-Associated Nutrients in the Everglades Ridge and Slough Landscape
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