Suzanne's Mom's Blog

I really liked this story about an effort in Costa Rica that is helping restore tropical forests. A study says that although “it’s not a license to kill” forests, they can come back eventually if humans just leave them alone to heal.

Tik Root writes at the Washington Post, “Deforestation is a global and accelerating threat. But new research shows that tropical forests can recover naturally and remarkably quickly on abandoned lands.

“The study, published [in] the journal Science, found that under low-intensity use, soil on previously deforested land can recover its fertility in less than a decade. Characteristics such as the layering of plants and trees in a forest, as well as species diversity, came back in about 25 to 60 years.

“ ‘I was totally surprised how quickly it went,’ said Lourens Poorter, an ecologist at Wageningen University in the Netherlands and lead author on the paper.

‘These forests can recover very fast and they can do it by themselves.’

“Burgeoning secondary forests are good for the climate as well. They are able to sequester more carbon dioxide from the atmosphere than established forests; like the voracious food intake of a sprouting teen compared to that of an older adult.

“ ‘It does provide a glimmer of hope for this process of tropical reforestation,’ said Meg Lowman, a conservation biologist and author of The Arbornaut: A Life Discovering the Eighth Continent in the Trees Above. ‘My only caution is that I don’t think it’s ever a substitute for the importance of saving big trees and old growth forests.’

“Older forests ultimately store more carbon dioxide than young forests, and deforestation releases those stockpiles, which helps drive climate change. The study found that it took more than a century for the overall biomass of tropical forests — and thus their carbon storage ability — to return fully. The recovery of a forest’s species makeup lasted a similar period.

“The longer time frame for the revival of these key benefits is among the reasons that Poorter says maintaining current forest cover is crucial. ‘First, stop deforestation and conserve old growth forests,’ he emphasized. The fact that deforested land can recover ‘is not a license to kill.’

“A 2019 study estimated that some 5.5 million hectares of tropical forest — an area more than twice the size of Belize — is lost each year to expanding commercial cropland, pastures and tree plantations. But cleared land is often abandoned as cultivation shifts, said Poorter, and researchers wanted to know, ‘Can it recover?’

“The answer is yes. … The subsurface soil, for example, often remains relatively vibrant after deforestation, which enables a faster recovery. The warmth and humidity of the tropics also allow trees to grow extremely fast, with some species climbing more than a dozen feet per year.

“And this all happens largely without human intervention, Poorter said. Seeds, roots and stumps embedded in the soil, or the spread of plants from adjacent forests, kick-start the recovery process. … ‘The conditions are that there has to be nearby forests, and the soil can’t be too degraded.’ “

The Post article continues with Daniel Nepstad, a tropical ecologist and president of the San Francisco-based Earth Innovation Institute, who says, ” ‘The research bolsters the policy argument for a nature-based approach to forest restoration. The cheapest way to get forest back on the land is to let nature do the work.’

“He would encourage governments to incentivize farmers and landowners to protect secondary forests and promote regrowth.

“Organizations such as the Natural Capital Project advocate for similar approaches to ecosystem services restoration. Costa Rica recently won Prince William’s Earthshot Prize for a program that helps reverse deforestation by paying farmers to protect and reforest their land. …

“This paper drew on 77 sites in three continents, comprising 2,275 plots and 226,343 stems.”

More at the Post, here.