News Style

Christopher D. Philipson, Mark E. J. Cutler, Philip G. Brodrick, Gregory P. Asner, Doreen S. Boyd, Pedro Moura Costa, Joel Fiddes, Giles M. Foody, Geertje M. F. van der Heijden, Alicia Ledo, Philippa R. Lincoln, James A. Margrove, Roberta E. Martin, Michelle A. Pinard, Glen Reynolds, Martijn Snoep, Hamzah Tangki, Yap Sau Wai, Charlotte E. Wheeler, David F. R. P. Burslem (2020). Active restoration accelerates the carbon recovery of human-modified tropical forests. Science. DOI: 10.1126/science.aay4490

The Upshot

More than half of the world’s aboveground carbon is stored in tropical forests, the degradation of which poses a direct threat to global climate regulation. Deforestation removes aboveground carbon in the form of trees, reducing the size of global carbon stocks in the process. Once forests are degraded, they are often perceived to have little ecological value and become prime candidates for full conversion to agricultural plantations.

Now, an international team of scientists from 13 institutions has provided the first long-term comparison of aboveground carbon recovery rates between naturally regenerating and actively restored forests in Malaysian Borneo. The researchers found that restoration practices improved carbon storage recovery by more than 50% compared to natural regeneration. The paper was published today in Science.

The Discovery

Areas left to regenerate naturally recovered by as much as 2.9 tons of aboveground carbon per hectare of forest each year, highlighting the ability of degraded forests to recover if protected from full agricultural conversion. The researchers also found that forest areas that underwent active restoration recovered 50% faster, from 2.9 to 4.4 tons of aboveground carbon per hectare per year. Restoration methods included planting native tree species, removing tree-climbing vines, and thinning vegetation around saplings to improve their chances of survival. Full ACD recovery in a naturally regenerating logged forest took around 60 years, while recovery for an actively restored forest took just 40 years.

The Impact 

“Not long ago, we treated degraded tropical forests as lost causes. Our new findings, combined with those of other researchers around the world, strongly suggest that restoring tropical forests is a viable and highly scalable solution to regaining lost carbon stocks on land. Science has laid out a clear pathway for land managers. We now must turn to the economics of the problem to generate the support to pursue these solutions,” said co-author and GDCS director Greg Asner. “Restoring degraded tropical forest works to mitigate climate change, and it saves biodiversity along the way,” he added.

The Researchers

See the publication for full list of authors and affiliations.