Carbon dioxide and water exchange between land and atmosphere

The Eddy Covariance flux tower in Vuwani, Limpopo Province. (© )

Understanding the cycling of carbon between the land surface and atmosphere is crucial for creating climate change scenarios and for the planning of climate adaptation strategies. Our team at the Thünen Institute of Climate-Smart Agriculture (TI-AK), together with local collaborators CSIR, GADI and the University of Venda, built four Eddy Covariance (EC) flux towers in South Africa (see Karoo 1&2, Vuwani and Agincourt in the map) as part of the project ARS AfricaE (2014-2018). Together with the two previously existing EC towers in the Kruger National Park (see Malopeni and Skukuza in the map), these towers form the central measurement infrastructures of the project.

The six EC towers produce continuous measurements of the fluxes of CO2 and water. Via these measurements, we can assess which climatic factors have a major role in affecting primary production and carbon uptake potential. By comparing sites that are under various intensities of livestock grazing, we can disentangle the impacts of climate from the impacts of land management.

The carbon flux data are also used together with the ecophysiological measurements and remote sensing data to improve vegetation models. This way, we can better understand the overall carbon balance of the studied ecosystems, and how it is impacted by climate change and human management.

In the long term, the EC towers strengthen and complement the South African environmental observation network (EFTEON). One of the main foci of this work area is to provide EC-related training to build up local capacity in South Africa. 

Team: Christian Brümmer (subproject lead, TI-AK), Justin du Toit (GADI), Graham von Maltitz (CSIR), Gregor Feig (EFTEON), Eric Maluta, Sampie Mathebe & Sophie Mulaudzi (University of Venda), Mari Bieri (TI-AK). Contact: mari.bieri@thuenen.de