PARENT SESSION
Oral Session #17: Wetland Ecology. Presiding: E. Weiher.
Monday, August 6, 2001. 1:00 PM to 4:15 PM. Hall of Ideas H.
Investigating tree island community response to increased water flow in a southern Everglades ecosystem .
Gann, Tiffany1, Childers, Daniel 1, 1
ABSTRACT- Freshwater flow is the subject of great interest concerning Everglades restoration. The effects of restoring freshwater flow to the system are suggested to not only increase flow, but also increase nutrient inputs to downstream communities. Tree islands are ecologically important communities in the Southern Everglades, and this area is currently receiving canal water delivery as part of hydrologic restoration. Local nutrient cycling and forest dynamics of the islands are key to understanding the relationship between wetland management and tree island function. To investigate this relationship, we are currently quantifying the structure, growth, nutrient utilization and soil dynamics of the mixed swamp tree islands. An experimental design is being utilized with "flow" (islands experience both flow and nutrient effects of canal water delivery), "walled" (islands experience only nutrient effects), and "no flow" (islands have greatly reduced flow and nutrient effects) treatments. Nitrogen imports due to canal water delivery may be taken up by these forested wetlands, and are hypothesized to increase litterfall production, tree growth rates, decomposition rates, and decrease nitrogen use efficiency. Preliminary data show that tree island communities efficiently utilize both phosphorus and nitrogen, and that, within one year, effects from increased freshwater flow are most pronounced in the "flow" treatment, specifically with respect to soil oxidation-reduction and litter turnover.
KEY WORDS: landscape heterogeneity, nutrient economy, water flow, Everglades restoration