Abstract:

This dataset contains values for monthly (May – September 2012) measurements of net soil greenhouse gas (CO2, CH4, and N2O) fluxes at 4 locations (5, 10, 15, and 20m from the marsh edge) from 4 Terrebonne Bay, Louisiana marsh sites. These sites include paired oiled and unoiled marshes in the Bay LaFleur and northern Lake Barre regions of Terrebonne Bay. Additionally, we measured a series of basic soil properties (soil organic matter, organic C, total N and total P, water content) and characterized the dissolved inorganic nutrient concentrations in overlying water samples.

Suggested Citation:

Roberts, Brian, and John Marton. 2016. Terrebonne Bay marsh soil net greenhouse gas fluxes and explanatory variables, May - September 2012. Distributed by: GRIIDC, Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/N7MS3QN8

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 component of the CWC research effort addressed the following questions: 1) Do greenhouse gas fluxes vary seasonally and/or with marsh position?; 2)What are the primary drivers of net greenhouse gas fluxes?; and 3) Are these results different between oiled and unoiled marshes?

Data Parameters and Units:

Region- region of sample collection (TB- Terrebonne Bay) Site- Site identifier Latitude (decimal degrees) Longitude (decimal degrees) Oil status--Indicates whether the marsh received Macondo Oil (Oiled) or not (Unoiled) Plot--Plot identifier along the sampling transect Distance (m)--Distance from the marsh edge of the sampling plot (meters) Month-Year--Indicates the month and year that samples were collected or measurements made net CO2 flux- net CO2 flux from the soil to atmosphere (micromol per meter squared per day) net CH4 flux- net CH4 flux from the soil to atmosphere (micromol per meter squared per day) net N2O flux- net N2O flux from the soil to atmosphere (micromol per meter squared per day) Soil OM (%)- soil organic matter content of the top 5cm of soil at the plot soil organic C (%)--organic carbon content of the top 5 cm of soil at the plot soil total N (%)--total nitrogen content of the top 5 cm of soil at the plot soil total P (µg/g)--total phosphorus content of the top 5 cm of soil at the plot soil CN (mol:mol)--organic carbon to total nitrogen ratio of the top 5 cm of soil at the plot soil NP (mol:mol)--total nitrogen to total phoshorus ratio of the top 5 cm of soil at the plot soil CP (mol:mol)--organic carbon to total phosphorus ratio of the top 5 cm of soil at the plot soil water content (%)--gravimetric water content of the top 5 cm of soil at the plot water depth (cm)--depth of overlying water at plot Salinity (psu)--salinity of overlying water at plot Overlying water NO3-N + NO2-N (micromols per liter)--dissolved nitrate + nitrite concentration of overlying water at plot Overlying water NH4-N (micromols per liter)--dissolved ammonium concentration of overlying water at plot Overlying water PO4-P (micromols per liter)--dissolved orthophosphate concentration of overlying water at plot Overlying water SiO2 (micromols per liter)--dissolved silicate concentration of overlying water at plot

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