Biogeochemical comparison of Spartina alterniflora and Avicennia germinans soils, Barataria Bay, LA wetlands, June 2013

We compared several key biogeochemical processes in soils dominated by Spartina alterniflora and Avicennia germinans. We sampled four sites in Barataraia Bay, Louisiana in June 2013 that had distinct patches of both species. Two of these sites were oiled following the 2010 Deepwater Horizon oil spill, and the remaining two sites were unoiled. We collected four 5-cm deep cores from each vegetation type at each marsh for a total of 32 soil cores. For each core we quantified the following biogeochemical process rates: nitrification potential, greenhouse gas (CO2, CH4, N2O) production, and iron reduction. We also measured microbial abundances (ammonia-oxidizing bacteria and archaea, and methane-oxidizing bacteria) and a suite of soil properties (soil organic matter, sand content, water content, organic carbon, total nitrogen, total phosphorus, pH, extractable NO3-N, NH4-N, and PO4-P, and total Fe).