Tropical mountain forests in Africa have been shown to store more carbon per hectare in their above-ground biomass than all other tropical forests on Earth.
Researchers at the University of Bayreuth said the forests have made a major contribution to preventing climate change and called for their immediate protection.
They examined carbon storage in the above-ground biomass of mountain forests on 226 selected plots spread over 44 regions in 12 African countries.
The results showed that Africa’s tropical mountain forests store an average of 149.4 tonnes of carbon per hectare, nearly double the Intergovernmental Panel on Climate Change’s (IPCC) previous estimates of just 89.3 tonnes of carbon per hectare.
The average storage capacity of the above-ground biomass of tropical forests in Central and South America and the Caribbean, as determined in earlier research, is considerably lower than that of tropical montane forests in Africa.
“Especially in East Africa, most forests are located in mountainous regions, so they are of crucial importance here for the carbon cycle and climate protection,” said researcher Dr Andreas Hemp.
“Our study, which has quantified this storage capacity for the first time, makes clear the ecological damage that further clearing of mountain forests would cause. Conversely, it also shows the benefits of the reforestation measures supported by many African states.
“Based on previous research, it has been established that African mountain forests are biodiversity hotspots and are home to a large number of endemic plant and animal species, i.e. species that do not exist anywhere else on earth. This insight alone confirms that efforts to preserve these resources should be intensified.”
For the study, the researchers carried out systematic measurements in mountain forests on Mount Kilimanjaro. They worked out the amount of carbon stored based on the height, circumference and wood density of the tree trunks.
Due to the rarity of destructive cyclones in Africa, the comparatively high carbon stocks of African tropical forests are based not least on the high storage capacity of very large trees, which can grow undisturbed in both mountain and lowland regions. The tallest trees in Africa are found on Mount Kilimanjaro, an area that Hemp has heavily studied over the last 30 years.
While planting trees has been seen as one possible way to sequester carbon dioxide from the atmosphere, a group of scientists warned last year that there was too much reliance on promoting this solution from high carbon companies.
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