Abstract:

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).

Suggested Citation:

Roberts, Brian and John Marton. 2016. Biogeochemical comparison of Spartina alterniflora and Avicennia germinans soils, Barataria Bay, LA wetlands, June 2013. Distributed by: GRIIDC, Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/N700001V

Purpose:

This dataset was developed as part of a research project investigating the effects of the Deepwater Horizon oil spill on salt marsh biogeochemistry. This particular project was directed to determine if the northward migration of the black mangrove alters the soil’s response to oiling.

Data Parameters and Units:

Site- Site Identifier Vegetation- Vegetation type (Avicennia germinans, Spartina alterniflora) Oil History- Indicates whether site received Macondo oil (oiled) or did not (unoiled) Latitude (decimal degrees) Longitude (decimal degrees) Core- Core number (4 collected per vegetation, per site) Water Depth- Depth of water (cm) on marsh surface at time of collection Salinity- Salinity (ppt) measured in water on marsh surface at time of collection CO2 Production- Soil CO2 production during anoxic soil slurries (nM CO2 per dry gram of soil per day) CH4 Production- Soil CH4 production during anoxic soil slurries (nM CH4 per dry gram of soil per day) N2O Production- Soil N2O production during anoxic soil slurries (nM N2O per dry gram of soil per day) Microbial Fe reduction- Microbial iron reduction (nM Fe2+ per dry gram of soil per day) Nitrification- Nitrification potential (nM NO3+ per dry gram of soil per day) Sand content—percent sand content of top 5cm of soil determined via hydrometer method (4 cores were pooled per site-vegetation and then analyzed in duplicate) Water Content- Gravimetric soil water content (%) of the top 5cm of soil Organic Matter- Soil organic matter content (%) of the top 5cm of soil Organic C- Soil organic carbon (%) of the top 5cm of soil Total N- Soil total nitrogen (%)of the top 5cm of soil C:N- organic carbon to total nitrogen ratio of the top 5cm of soil Total P- Soil total phosphorus (µg of phosphorus per dry gram of soil) of the top 5cm of soil N:P- total nitrogen to total phosphorus ratio of the top 5cm of soil pH- pH of the top 5cm of soil at time of collection PO4-P- Sodium bicarbonate extractable soil phosphate (nM PO4-P per dry gram of soil) of the top 5cm of soil NO3-N- Potassium chloride extractable soil nitrate (nM NO3-N per dry gram of soil) of the top 5cm of soil NH4-N- Potassium chloride extractable soil ammonium (nM NH4-N per dry gram of soil) of the top 5cm of soil Fe- Total extractable iron (µM per dry gram of soil) of the top 5cm of soil MOB- Abundance of methane-oxidizing bacteria (pmo gene copies per dry gram of soil) of the top 5cm of soil AOA- Abundance of ammonia-oxidizing archaea (amoA gene copies per dry gram of soil) of the top 5cm of soil AOB- Abundance of ammonia-oxidizing bacteria (amoA gene copies per dry gram of soil) of the top 5cm of soil AOA:AOB- Ratio of AOA abundance to AOB abundance of the top 5cm of soil

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