A surprising store of carbon in the tropical mountains

Tropical mountain forests, forests growing at more than 1000 metres above sea level, are known to be important regulators of downstream water availability, as well as regions of high biodiversity. Their other roles, in terms carbon storage for example, are less well understood. The steep terrain means that measurements on the ground are difficult to acquire, and the clouds that often obscure these forests make remote sensing challenging.

In a recent study published in Biogeosciences, LEAF scientist Dr Dominick Spracklen and Professor Renton Righelato from the University of Reading, tried to resolve this issue by synthesising the observations of above-ground biomass that are available. They also used remote sensing data to determine the area covered by the forests, and examine their topography.

“We found that three quarters of tropical mountain forests are growing on steep slopes, at an angle of more than 27 degrees. This means that the total area covered by these forests is 40% greater than the area reported on maps” explains Dr Spracklen.

This additional areal coverage has implications for the amount of carbon stored by the forests, which Spracklen and Righelato calculate to be an average of 271 tonnes per hectare of land surface. “Our study demonstrates that tropical mountain forests are globally important stores of carbon, providing more justification to protect these forests," added Dr Spracklen.