Woody encroachment and thickening is a global phenomenon, altering the composition of plant functional types within biomes, and changing ecosystem processes and feedbacks. Current consensus is that global change, in the form of increasing atmospheric CO₂ concentrations and changing rainfall patterns, together with local land management strategies such as fire suppression and stocking densities, are the drivers of the emerging landscape patterns. Sweet thorn Acacia (Vachellia karroo) is an endemic to southern Africa, but it is encroaching into grassland systems and threatening livelihoods. However, the species’ status as a non-listed invasive (National Environmental Management: Biodiversity Act 2004, Act No. 10, Alien and Invasive Species Lists) limits control and eradication options. Together with our lack of insight into how ecosystem processes are changing, this phenomenon poses a conundrum to management and decision making from the farm to national level. Using a case study in Adelaide, Eastern Cape, we use the open path eddy covariance technique in a paired tower design together with remote sensing (MODIS and MISR-HR products) to quantify the impact of woody thickening on water, carbon, and energy fluxes and rangeland productivity. We present the results of the 2018-2019 growing and dry seasons and the longer-term patterns in changing ecosystem feedbacks.
Audio/Video, Conference Presentation, SER2019
Pre-approved for CECs under SER's CERP program
Society for Ecological Restoration