The savanna biome, defined by the co-dominance of trees and grasses, is characterized by its large variability in tree cover. In stationary environmental conditions, our inability to predict vegetation structure presents challenges for management, but is of particular concern in the face of accelerating climate change. What effects are rising temperatures and changing precipitation patterns likely to have on vegetation structure? We present results from a series of observation studies from Kruger National Park in South Africa, examining patterns of spatial and temporal variability in grass and tree savanna components.
Results/Conclusions
Grass biomass has increased since the 1980s significantly throughout the park, independent of any systematic climate or herbivore population trends; in arid regions (MAR ~= 300mm per annum), grass biomass has increased by up to 1.5x. This has translated into measurable increases in burned area throughout the park. Meanwhile, tree distributions have also increased and shifted, although we also find evidence that tree distributions in the landscape are surprisingly predictable, given variability in tree density at a small-scale. We will discuss implications for savanna ecosystem persistent more broadly under global change scenarios.