COS 71-6
Decomposition and vegetation survey: A way to assess ecosystem functional performance and structural characteristic of resacas
The objectives of this study were to collect baseline data to classify resacas as wetland ecosystems and describe their functional and structural characteristics. Vegetation surveys were used as a structural characteristic to classifying 6 systems as wetlands. Decomposition and water quality data were used to functionally characterize the resacas. The three rural resacas assessed decomposition rates using native Sabal mexicana leaves for a period of 60 days. The senescent Sabal mexicana leaves were placed in nylon mesh bags with replicates of 3 and attached to 5 centrally positioned poles along each resaca. The collections were taken after 14, 30, 60 days. The decomposing leaves were cleaned, dried, weighed and burned to obtain ash free dry weight. A line point intercept method was used (mid-summer and early spring) to assess aquatic vegetation and the point intercept method was used to assess floating vegetation abundances. Water samples were collected once a month to assess water quality (pH, conductivity, water depth) and test nitrate and phosphate concentrations. The USFWS Wetlands and Deepwater Habitats Classification Systemwas used to classify resacas as wetlands.
Results/Conclusions
A functional description is in progress but, a preliminary analysis has yielded a structural description of a resaca. A resaca is a shallow freshwater palustrine wetland with an unconsolidated bottom which possesses a forested historical floodplain, an aquatic bed of algae, or floating and rooted vegetation. It also may possess persistent emergent vegetation and maintains a flooded or saturated hydrologic regime through artificial use of a pipe system.