I study the ecology of plants, particularly the herbaceous (non-woody) component of tropical and subtropical savannas and grasslands in north-eastern South Africa, and how these systems are impacted and defined by various disturbances, including fire frequency, herbivory, alien invasive taxa, nutrient flux, and climate extremes. These grassy biomes underpin critical ecosystem services and functions, and my research is focused on better understanding plant population dynamics and predicting the potential negative effects imposed by land-use intensification, inappropriate land management, and climate change.
South African grasslands are species rich botanically, as is the often over-simplified view of the non-woody component of local savannas. These herbaceous communities are co-dominated by grass and forb species (wildflowers) which make significant contributions to the overall floral diversity and abundance. Natural and anthropogenic ecological disturbances, including fire, herbivory, alien invasive taxa, nutrient flux and climate – particularly when acting in combination – strong govern community composition and dominance, taxonomic and functional diversity, and productivity of these systems, as well as the critical ecosystem services (e.g. climate and water regulation, carbon sequestration) and functions (e.g. forage for livestock, wildlife and people, provision of habitat) that they support. Disturbance extremes outside the bounds of what is considered ‘normal’ – for example complete fire suppression, over-grazing, or frequent severe drought, act as ecological filters which result in depauperate and functionally-depressed communities.
