A study by researchers at Saint Louis University has found that elephants play a key role in creating forests that store large amounts of atmospheric carbon and in maintaining the biodiversity of forests in Africa. Since elephants are endangered, their status represents a significant threat to an ecosystem that is very important to the Earth’s climate.
The African rainforest contains trees with both low carbon density (light wood) and high carbon density (heavy wood). High carbon density trees grow more slowly and can be crowded out by the faster growing low carbon density trees rising above them. Elephants affect the relative abundance of these trees by feeding more on the low carbon density trees which are more palatable and nutritious. This thinning of the forest allows the trees that sequester the most carbon to flourish.
Elephants are also excellent dispersers of the seeds of high carbon density trees. Essentially, elephants are the gardeners of the forest. They plant the forest with high carbon density trees and get rid of the weeds – in this case, the low carbon density trees. According to the study, if elephants were to become extinct, the African rainforest – the second largest on earth – would gradually lose between six and nine percent of its ability to capture atmospheric carbon.
Elephants have been hunted by humans for millennia. Gaining support for protecting them has mostly been driven by the argument that everybody loves elephants. Focusing on their role in maintaining forest diversity has not driven much more action. The hope is that the evidence of how important elephants are for climate mitigation will be taken seriously by policy makers to generate the support needed for improved elephant conservation.
Photo, posted March 15, 2008, courtesy of Michelle Gadd/USFWS via Flickr.