Mpala Research Centre was established in 1994 in the heart of Kenya’s Ewaso ecosystem. This region of central Kenya is bounded by the Ewaso Ng’iro River and its tributaries, and is characterized by arid to semi-arid savannas and shrublands. Two main savanna soil types – black cotton and red soils – are encompassed by the 20,000ha research site. On the black cotton soils, the savanna is dominated by only one species of tree: the Whistling Thorn Acacia, Acacia (syn. Vachellia) drepanolobium. This tree has a mutualism with aggressive ants, which are housed inside of the tree and help protect it from herbivory from megafauna such as elephants and giraffes. We are using LiDAR and multispectral drone data to investigate this keystone tree species at landscape scales, including monitoring its responses to fire.
The plant community on the red soil is more diverse, including upwards of 500 species of grasses, forbs, and trees. Our work in this system takes advantage of a number of long-term herbivore exclosure studies that, collectively, provide insights into the impacts of Mpala’s 22 native large herbivore species on the savanna plant community. Current projects in this system rely on a combination of long-term field surveys and LiDAR data; with these, we hope to better understand how variation in plant diversity affects vegetation structural complexity, disentangle how herbivory (and simulated herbivore extinction) affects vegetation communities, and estimate the net effect of plant-plant mutualisms on herbaceous biomass at the landscape scale.