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publications > paper > the contribution of leaching to the rapid release of nutrients and carbon in the early decay of wetland vegetation
The contribution of leaching to the rapid release of nutrients and carbon in the early decay of wetland vegetation
Stephen E. Davis III1,*, Daniel L. Childers2 & Gregory B. Noe3
1Department of Wildlife & Fisheries Sciences, MS 2258, Texas A & M University, College Station, TX 77843, USA
2Department of Biological Sciences & SE Environmental Research Center, Florida International University, Miami, FL 33199, USA
3U.S. Geological Survey, 430 National Center, Reston, VA 20192, USA
(*Author for correspondence: Tel.: +979-458-3475; Fax: +979-845-4096; Email: sedavis@tamu.edu)
| ©Springer 2006. Posted here with permission; Hydrobiologia (2006) 569:87-97. J.C. Trexler, E.E. Gaiser & D.L. Childers (eds), Interaction of Hydrology and Nutrients in Controlling Ecosystem Function in Oligotrophic Coastal Environments of South Florida.
A PDF version of this entire publication is available for download (332 KB) from the Water Resources of the United States website. You will need the free Adobe Acrobat Reader in order to view this file. |
Abstract
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| Figure 2. Releases of total phosphorus (TP) from each of four species of leaf material with poison (gray bars) and without
poison (white bars) incubated for 1 day (top graph) and for
21 days (bottom graph). Error bars represent standard deviations
from three replicates. Separate y-axis for S. alterniflora is
intended to show the magnitude of TP released from a N-limited
plant versus that of three P-limited, Everglades plant species
after 1 and 21 days of immersion in water. [larger version] |
Our goal was to quantify the coupled process of litter turnover and leaching as a source of nutrients and
fixed carbon in oligotrophic, nutrient-limited wetlands. We conducted poisoned and non-poisoned incubations
of leaf material from four different perennial wetland plants (Eleocharis spp., Cladium jamaicense,
Rhizophora mangle and Spartina alterniflora) collected from different oligotrophic freshwater and estuarine
wetland settings. Total phosphorus (TP) release from the P-limited Everglades plant species (Eleocharis
spp., C. jamaicense and R. mangle) was much lower than TP release by the salt marsh plant S. alterniflora
from N-limited North Inlet (SC). For most species and sampling times, total organic carbon (TOC) and TP
leaching losses were much greater in poisoned than non-poisoned treatments, likely as a result of epiphytic
microbial activity. Therefore, a substantial portion of the C and P leached from these wetland plant species
was bio-available to microbial communities. Even the microbes associated with S. alterniflora from
N-limited North Inlet showed indications of P-limitation early in the leaching process, as P was removed
from the water column. Leaves of R. mangle released much more TOC per gram of litter than the other
species, likely contributing to the greater waterborne [DOC] observed by others in the mangrove ecotone of
Everglades National Park. Between the two freshwater Everglades plants, C. jamaicense leached nearly
twice as much P than Eleocharis spp. In scaling this to the landscape level, our observed leaching losses
combined with higher litter production of C. jamaicense compared to Eleocharis spp. resulted in a substantially
greater P leaching from plant litter to the water column and epiphytic microbes. In conclusion,
leaching of fresh plant litter can be an important autochthonous source of nutrients in freshwater and
estuarine wetland ecosystems.
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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