To investigate potential contributions of savanna ecosystems to the Earth s carbon balance, an eddy covariance system was used to measure the seasonal variation in carbon dioxide, water vapor, and energy flux at the Maun micrometerological tower site in a broadleaf semi-arid savanna in Southern Africa, approximately 20 km east of Maun in northeastern Botswana. The open woodland studied consists of an overstory dominated by Colophospermum mopane with a sparse understory of grasses and herbs....