"What controls the growth rate of trees in African savannas"? A combination of simple measurements taken in the field over long periods of time, with high-technology instruments such as satellites and flux towers have allowed the researchers to construct, for the first time, relatively simple predictive models. These models have, in turn, allowed new light to be cast on several important problems. Keywords: Trees growth rate, African savannas, Fuelwood, Elephant numbers and conservation, Kruger National Park, Southern Africa.