Abstract

Savannas are globally important ecosystems of great significance to human welfare and economies. In Africa, the savannas are also home to the greatest density and diversity of large herbivores and carnivores of any ecosystem on earth. However, the mixture of trees and grasses that defines savanna systems is inherently unstable and multiple factors related to soil type, climate, herbivore density, and wild-fire frequency are thought to contribute to their coexistence. Thus savannas are biocomplex systems where processes such as grazing intensity and fire frequency simultaneously depend on and control savanna structure, productivity and nutrient recycling.

This Biocomplexity project will investigate ecological complexity in the context of African savannas. We are building the conceptual and numerical understanding of savanna ecosystems that will allow prediction of savanna structure and function resulting from the complex interactions and feedback between driving variables. Our aim is to investigate the role of climate, biogeochemistry, fire and herbivory in controlling savanna structure and function and the mechanisms that may lead to savanna stability, resilience and bifurcation dynamics. The project will include analysis of new and historical field measurements at plot to continental scales, simulation modeling, and dynamical systems analysis. The project will further use savanna systems as a general model for understanding complexity in biological systems and to develop methods of analysis and interpretive tools that promote a broader public understanding of the complexity and inter-relatedness of environmental systems.