The Botswana Kalahari Transect

Arid and semiarid ecosystems cover approximately 40% of the Earth’s land surface and are home to more than one third of the world’s human population. The Kalahari provides important ecosystem services, and shifts in the rainfall regime and land use patterns may result in changes in plant community composition with potentially severe implications for the ability of the land to provide these services. Politically and economically significant land use changes within the area have the potential to improve economic returns: recently, carbon storage has been identified as a potential source of income. Yet little is known about savanna total carbon storage and response to natural (e.g., climatic) or anthropogenic (e.g., fire, ranching) changes. The consistent (at a large scale) soils of the Botswana Kalahari combined with a documented rainfall gradient provide an excellent “open air laboratory” to study the effects of climate change on vegetation patterns, the distribution and production of biomass, and the region’s carbon storage capacity. No studies to date have provided both regional-extent and ecosystem-scale estimates of woody plant cover and biomass/carbon content of savanna ecosystems.

The Botswana Kalahari Transect is a research initiative spearheaded by the University of Virginia, University of Los Angeles and Princeton University. SGI supports PhD student Thoralf Meyer (Univ. of Virginia) to assess fractional cover of photosynthetic active vegetation, non-photosynthetic vegetation and soils, providing insight into how these components vary spatiotemporally along the rainfall gradient of the Kalahari. Intensive fieldwork is undertaken to collect aboveground vegetation data, leaf- and canopy-level spectral characteristics, and soil spectra and will be compared to soil carbon and belowground biomass/root distribution collected along the same transect. The project not only addresses hypotheses about the distribution of woody plants, vegetative cover, structure and carbon storage in the Kalahari it also provides an insight into the dependence of carbon stocks on climate in the Kalahari and will be relevant to understanding the effect of anticipated climate change in the region on above- and belowground carbon storage.

The research project is supported by National Science Foundation of the United States of America.