Data from: Carbon and water dynamics of Old World Bluestem in the U.S. Southern Great Plains

The dataset includes daily fluxes of net ecosystem CO2 exchange (NEE, g C m-2 d-1), gross primary production (GPP, g C m-2 d-1), ecosystem respiration (ER, g C m-2 d-1), and evapotranspiration (ET, mm d-1) from 2021 to 2024 for an Old World Bluestem pasture at the USDA-ARS, El Reno, Oklahoma.The study site, Old World Bluestem (OWB) pasture (~63 ha), was established in the 1980s on a native tallgrass prairie site. It is located at the United States Department of Agriculture – Agricultural Research Service (USDA-ARS), Oklahoma and Central Plains Agricultural Research Center, El Reno (35.5467º N, 98.0452º W, and 435 masl), Oklahoma.The eddy covariance (EC) tower was equipped with an open-path infrared gas analyzer (LI-7500 RS, LI-COR Biosciences, Lincoln, NE, USA) integrated with a three-dimensional sonic anemometer (CSAT3, Campbell Scientific Inc., Logan, UT, USA). These sensors were mounted at a height of ~2.8 m above the ground surface. The tower had enough fetch extending several hundred meters in all directions to ensure representative flux measurements from the OWB pasture.Raw high-frequency EC data were processed using EddyPro software (version 7.0.6, LI-COR Biosciences, Lincoln, NE, USA) in its Express configuration to compute half-hourly (30-min) fluxes. Gap-filling of half-hourly eddy fluxes and meteorological variables, as well as the partitioning of NEE (using nighttime partitioning) into its component fluxes (GPP and ER), was conducted using the REddyProc (https://www.bgc-jena.mpg.de/REddyProc/ui/REddyProc.php).