Master of Science (MS)
Oceanography and Coastal Sciences
Nutrient dynamics and seasonal marsh growth were examined in a newly formed Panicum virgatum floating marsh at Thibodaux LA. The floating marsh formed in a cleared area of forested wetland receiving secondarily treated effluent. Net Areal Primary Productivity (NAPP), total belowground biomass, NO3, and δ15N ratios varied significantly (P <0.05) along a 75m marsh transect while mean δ13C varied between plant species. The upland end of the transect had the highest NAPP (3876 g m-2y-1), total belowground biomass (4079.0 ± 298.5 g m-2), and mean NO3 (5.4 ± 2.9 mg l-1). The mean floating-marsh δ15N of H. umbellata was less enriched at 0-75 m (9.69 ± 1.9‰) compared to 100-200 m (20.99 ± 3.8‰). The δ13C of the belowground peat mat of the floating marsh was similar to P. virgatum but not H. umbellata, indicating that P. virgatum was forming the mat. There was a significant decrease in NAPP, total belowground biomass, NO3 and δ15N enrichment across the 75 m transect. Nutrient availability affected NAPP and δ15N. Floating marsh NAPP in the 0-45 m was greater than most reported values for floating marsh. These results suggest that nutreint rich freshwater can promote restoration of floating marshes.
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Izdepski, Caleb W., "Early flotant establishment and growth dynamics in a nutrient amended wetland in the lower Mississippi River delta" (2007). LSU Master's Theses. 683.
John W. Day, Jr.