Can Baobabs provide insight on climate change?
Recorded in the chemistry of the wood and the growth span of the tree is a history of climate patterns over the years. More baobabs – thousands of years old – have fallen in Pafuri, Mapungubwe and in Botswana since, and the baobab climate record has expanded. For the last three years, researchers from the University of Pretoria, Swansea University, University of Cape Town have studied additional baobabs from as far as Madagascar and Namibia.
Through coring the trees with a borer, dowels of wood can be removed without damaging the trees. The chemistry revealed through carbon isotope analyses of different tree rings gives scientists access to information on age and growth. These trees, found mostly in summer rainfall areas, make good study models as they can live for more than 1 000 years. The baobabs can also reveal periods of growth and water stress, and therefore related rainfall and drought periods over hundreds of years.
The emerging climate record is a highly resolved indication of how rainfall has varied across Namibia, Botswana, South Africa and Madagascar over the last 1000 years. The message that comes from the baobabs is being used in two ways. The first is a relatively simple exercise of seeing how the natural climate system varies. Revelations are that natural climate cycles vary drastically, owing to factors such as El Niño (la Nina) and regime shifts.
JB Dodane