SS4.12 Linking Science with Management of Freshwater Resources
Date: Thursday, June 13, 2002
Time: 4:45:00 PM
Location: Carson B
 
NoeG, Wetland Ecosystems Ecology Lab, Florida International Univ., Miami, USA, noeg@fiu.edu
Childers, D, , Wetland Ecosystems Ecology Lab, Florida International Univ., Miami, USA, childers@fiu.edu
Iwaniec, D, , Wetland Ecosystems Ecology Lab, Florida International Univ., Miami, USA, iwaniecd@fiu.edu
Madden, C, , Everglades Department, South Florida Water Management District, 3301 Gun Club Road, West Palm Beach, USA, cmadden@sfwmd.gov
Rondeau, D, , Wetland Ecosystems Ecology Lab, Florida International Univ., Miami, USA, rondeaud@fiu.edu
Rubio, G, , Wetland Ecosystems Ecology Lab, Florida International Univ., Miami, USA, rubiog@fiu.edu
Verdon, E, , Wetland Ecosystems Ecology Lab, Florida International Univ., Miami, USA, verdone@fiu.edu
 
ISOLATING WATER QUALITY AND HYDROPERIOD EFFECTS OF INCREASED FRESHWATER INPUTS TO SOUTHERN EVERGLADES WETLANDS USING LONG-TERM RECORDS OF SAWGRASS PRODUCTIVITY
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Several recent restoration projects have increased freshwater inputs to the Southern Everglades, with potential impacts of changes in both water quantity and quality. We used long-term sawgrass productivity data from 16 Southern Everglades sites to separate these two effects and predict restoration outcome. Annual production by sawgrass across this oligotrophic landscape was quite low (100 500 gdw/ m2/ yr). Surface water rarely showed elevated phosphorus concentrations (>0.3 uM TP) at canal-side sites, and we saw no sawgrass productivity response at these sites. We observed a long-term decline in sawgrass productivity across the landscape (1998 2001), including negative net annual production at many sites (up to 300 gdw/m2/yr). We related this regional pattern to concurrent changes in hydroperiod and mean inundation depth. The negative response of sawgrass productivity to enhanced freshwater inputs was expected because sawgrass typically grows in relatively short hydroperiod conditions. As hydroperiod increases, a more slough-like community should replace the sawgrass community. Our data suggest that a decline in sawgrass net productivity is the first step in this process, demonstrating the importance of such long-term data to Everglades restoration efforts.