|Africa: Forests Prove Valuable Carbon Sink|
African forests are adding to their mass each year by an amount equivalent to a small car per hectare, researchers have found. The finding has surprised researchers and confirms the forests' status as one of the world's substantial carbon sinks.
Researchers used data collected between 1968 and 2007 to calculate that 0.6 tonnes of carbon per hectare are added to African forests each year. While this has been shown in the Amazon, this is the first demonstration that African forests are taking in carbon.
There are two possible explanations. One is that the forests might not be in equilibrium, as was previously thought. All forests take in carbon as they grow. In the absence of disturbances they then reach equilibrium, when tree death and growth occur at the same rate. It could be that the seemingly undisturbed African forests are actually still recovering from past disturbances such as fires or mass logging - and therefore still growing.
Alternatively, changes in the global climate and atmosphere could have disturbed the forests' previous equilibrium. Increased carbon dioxide could be increasing tropical tree growth for example.
It is likely that both theories have a role to play, but scientists need a better understanding of carbon dynamics in tropical forests to know the answer, writes Helene C. Muller-Landau of the Smithsonian Tropical Research Institute in Panama.
The research also highlights the need to protect African forests, write the authors. "With adequate protection these forests are likely to remain large carbon stores in the longer term. Securing this service will probably require formalising and enforcing land rights for forest dwellers, alongside payments for ecosystem services to those living near forested areas."
Source: Nature (www.scidev.net)