DISERTATION RESEARCH: Effects of global climate change, loss of mega-herbivore biodiversity, and altered fire regimes on savanna grassland ecosystems

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Intellectual merit. Humans are altering the environment locally and globally through climate and land use change. Grasslands, which cover approximately one third of terrestrial lands, are ecologically and economically significant, thus their responses to environmental change will have dramatic consequences for productivity, biodiversity, and food production globally. This research consists of two field experiments. The first investigates how changes in the three main drivers of mesic grassland ecosystems - precipitation, grazing, and fire - interact to affect plant community composition, structure, and dynamics in North America (NA, Konza Prairie, KS) and South Africa (SA, Kruger National Park). The comparable experimental designs and identical sampling protocols in both NA and SA will permit generality of findings. The second proposed experiment will assess how small-scale patch structure and dynamics in SA grasslands respond to fire along a grazing utilization gradient. This experiment will provide information to tease apart how fire and grazing intensity alter grass-forb biodiversity in SA. Broader impacts. This research is directly relevant to the long-term management goals of Kruger National Park, which has implemented a scientifically driven management plan built around 'threats of particular concern,' including climate change, fire management, grazing pressure and biodiversity. In addition, this research is broadly applicable to mesic grasslands around the world where fire, grazing and climatic variability interact to affect biodiversity and ecosystem services. All research in Kruger occurs in collaboration with SANParks Scientific Services ensuring close communication between scientists and managers. This research will result in international field experience and collaborative research training for a young female scientist.