African forests and their role on greenhouse gases budget
Researchers increasingly recognise the importance of African tropical forests to global climate change, although the details are not well studied. Forests are very important for carbon sequestration, while deforestation contributes to carbon release. The EU-funded AFRICA-GHG (AFRICA-GHG: the role of African tropical forests on the greenhouse gases balance of the atmosphere) project studied the balances of various greenhouse gases in relation to forest biogeochemical dynamics. Specific fluxes studied included carbon dioxide, water, nitrous oxide, and methane, most of which are strong greenhouse gases. Against undisturbed tropical rain forest, the study also compared the gas-release effects of logging. The team used different techniques, including eddy covariance, remote sensing, LIDAR and sophisticated measurements of soil emissions. The work showed that while Africa represents a small carbon sink (absorbing more carbon than it gives off), the emissions of methane and nitrous oxide make Africa a source of greenhouse gases. Tropical rainforests contribute to carbon sequestration. The process does not occur via tree growth, but rather through soil carbon sequestration or leaching. Logging causes long-term degradation of forest biomass and biodiversity, while clearing of land for farming releases significant amounts of carbon dioxide and nitrous oxide. The team concluded that deforestation releases far more greenhouse gases than unlogged forest may uptake. The project helped determine the over-all balance of greenhouse gases with respect to natural and logged forests. The work demonstrated the greenhouse consequences of African logging.
Keywords
Africa, forests, climate change, greenhouse gases, fluxes, biomass
