The Kafue Flats Wetlands in central Zambia has experienced significant spread of the alien invasive shrub, Mimosa pigra (mimosa). Efforts are ongoing to remove up to 95% of the current 3,000 hectares of mimosa cover in Lochinvar National Park (LNP) with the aim of restoring this area to increase biodiversity. The restoration area hosts large populations of Kafue Lechwe antelope which feed on fresh grass regrowth in the cleared areas. Hence, it is likely that they will affect vegetation recovery, but it is unknown which species, native or alien, they will particularly support during this process. Our study therefore focused on answering the question: how does herbivore grazing impact vegetation restoration after large scale invasive plant removal? Five months after mimosa removal, we commenced a two- year field experiment in LNP with eight paired plots. At each paired plot, one plot is fenced to prevent grazing and the other unfenced to allow grazing. We have measured the initial vegetation parameters in these experimental plots: i.e., seedling density of mimosa and diversity and composition of the native plant community. Initial results after five months of experimental treatments show that the lechwe herbivores do indeed influence vegetation recovery. Grazed plots had a higher mimosa seedling density, and a lower cover, biomass, and species richness of the native community than the fenced plots. These early results suggest that large-scale restoration projects should factor in the influence of grazing – and its management – to optimise restoration efforts and their subsequent biodiversity benefits.
Audio/Video, Conference Presentation, SER2019
Society for Ecological Restoration