According to the results of the study, the natural regrowth of tropical forests has great potential to solve environmental problems

A to learn in Nature finds that up to 215 million hectares (an area larger than Mexico) in the world’s humid tropics have the potential to regenerate naturally.

This amount of forest can store 23.4 gigatons of carbon over 30 years, and also the loss of biodiversity and water quality. The study found that more than half of the area with strong potential for regrowth is in five countries: Brazil, Mexico, Indonesia, China and Colombia.

“Planting trees in degraded landscapes can be costly. By using natural regeneration techniques, states can effectively meet their restoration goals,” said study co-author Brooke Williams, a researcher at Queensland University of Technology in Australia. Institute for the Exchange of Skills in Environmental Decisions.

“Our model can guide where these savings can best be used,” he says.

The culmination of decades of work

Matthew Fagan, associate professor of geography and environmental systems at the University of Maryland, Baltimore County (UMBC) and co-author of the new study, produced the data set the authors relied on.

In that business“We used satellite images identifying millions of small areas where tree cover has increased over time. We then excluded human-planted areas with machine learning, focusing on natural growth,” Fagan said.

The study tracked the regrowth between 2000 and 2012 and then checked whether the regrowth continued through 2015. “Those natural patches were the input data for this new study,” he said, “which was the first to predict where future forest growth will occur by observing past regrowth.”

The study was conducted with Hawthorne Beyer, head of geospatial science at Mombak, a Brazilian startup that aims to generate high-quality carbon credits through Amazon forest restoration, and Hawthorne Beyer, director of science at the Institute for Competence Exchange in Environmental Decisions. in global datasets describing factors such as soil quality, slope, road and population density, local wealth, distance from urban centers and healthy forest, etc.

“When you set up one of these global studies, you’re standing behind a lot of other scientists,” Fagan said. “Each of these studies represents years of hard work.”

The study found that the factors most strongly associated with high growth potential were patch proximity to existing forest, density of nearby forest, and soil carbon content. These factors in particular “do a really good job of explaining the patterns of regrowth that we’re seeing around the world,” Fagan says.

Fagan explains that being close to an existing forest, for example, is key to providing a variety of seeds to an area to support diverse growth.

Keeping it local – by providing a global map

The final product of the study is a digital map of the global tropics, where each pixel (representing an area of ​​30 x 30 square meters) shows the estimated potential for regrowth. Made possible by an extensive international collaboration of researchers, this map is a boon to environmentalists worldwide hoping to champion their efforts locally.

“Our goal and hope is that this will be used democratically by local people, organizations and regions, from the county level to the national level, to advocate for where recovery needs to be,” Fagan says.

“The people who live there should be responsible for what happens there – where and how to restore really depends on local conditions.”

Fagan notes that some of the potential regrowth areas identified by the study are unlikely to be restored for a variety of reasons, such as being in active use for ranching and agriculture, or being located on prime real estate near roads and urban centers.

However, a significant portion of the 215 million hectares are abandoned and degraded cattle pastures or previously logged forests, where promoting natural regeneration would have minimal costs and a long list of benefits for local economies.

“If you put it back into the rainforest, the benefits to water quality, water supply, native biodiversity and soil quality would be huge,” Fagan said.

“It would also be of great benefit to removing carbon from the atmosphere, so it’s really a question of ‘Where can we do that most efficiently?’ And that’s what this paper is about.”