Wind speed, wind direction (3D) and gas concentrations are measured at 10 Hz and statistically processed using the eddy covariance technique to half-hour estimates of flux rates of gas exchange between the ecosystem and atmosphere. Three gases were measured: carbon dioxide, methane and water vapor. Simultaneous measurements of environmental drivers are also measured and recorded as half-hourly values: photosynthetic photon flux density, downwelling and upwelling short and long wave radiation, air temperature, relative humidity and precipitation. Variable names and units follow AmeriFlux and FLUXNET standards. This site is a flotant herbaceous freshwater marsh in Salvador Wildlife Management Area near Luling, LA.