African tropical mountain forests store 2/3rd more carbon than previously estimated: Study

Tropical mountain forests in Africa store more carbon in their above-ground biomass than all other tropical forests, according to a new study. 

The study, published in journal Nature August 25, 2021, found that tropical mountain forests in Africa store 149.4 megagrams of carbon per hectare — two-thirds more carbon than the Intergovernmental Panel on Climate Change (IPCC) estimates of average 89.3 megagrams of carbon per hectare.

One megagram equals one tonne. 

The study, which analysed the storage capacity in numbers for the first time, was conducted by researchers at the University of York.

The study makes clear the ecological damage that further clearing of mountain forests would cause.

The researchers examined carbon storage in the above-ground biomass of mountain forests on 226 selected plots spread over 44 mountain sites in 12 African countries — from Guinea in the west to Ethiopia in the east to Mozambique in the south.

Aida Cuni-Sanchez, lead author of the study, said:

“The results are surprising because the climate in mountains would be expected to lead to low carbon forests. The lower temperatures of mountains and the long periods they are covered by clouds should slow tree growth, while strong winds and steep unstable slopes might limit how big trees can get before they fall over and die.”

The researchers also investigated tropical mountain forests lost from the African continent in the past 20 years.

They found over 0.8 million hectares were lost in Africa since 2001, with the Democratic Republic of the Congo amounting for the highest loss (536,000 ha), followed by Uganda (65,000 ha) and Ethiopia (62,000 ha).

In terms of percentage, Mozambique and Ivory Coast lost over 20 per cent of their mountain forests over this period. These forests are under threat from logging, mining and land clearance for farming.

If deforestation continues Africa at the current rate, a further 0.5 million hectares of these forests would be lost by 2030, the report warned.

African tropical mountain forests are not only rich in carbon, but also offer habitat for many rare and endangered species and regulate local temperatures.

Beyond protected areas, other forest conservation mechanisms could be implemented, including effective carbon finance, said the study.

Most African countries have committed large amounts of land to forest restoration under the Bonn Challenge. Forest restoration is important to mitigate climate change.

Launched by the Government of Germany and IUCN, the Bonn Challenge is a global goal to bring 150 million hectares of degraded and deforested landscapes into restoration by 2020 and 350 million hectares by 2030.