In mid-March of this year we learned of the publication of the Global Forest Watch annual report, based on satellite data, according to which by 2020 the destruction of 4.2 million hectares of primary tropical forests (equivalent to the size of the Netherlands), crucial for the planet’s biodiversity and carbon storage.
In 2018, for example, the primary tropical forest had already lost 3.6 million hectares, an area equivalent to that of Belgium. And Brazil became the most affected country, with a lost area that would be the equivalent of three times more than the Democratic Republic of the Congo, second in the ranking.
And in that report, the experts pointed out that it was not surprising to find that, in reality, the main driver of this destruction continues to be agriculture . In fact, in the tropics, trees tend to be cut down to make way for farmland , which is subsequently abandoned when the soil is no longer productive.
However, it appears that tropical forests can quickly reestablish and recover on land that was originally deforested for agriculture and later abandoned, suggesting that so-called “reclaimed forests”, also called “secondary forests”, may end up playing a role. key in the restoration of ecosystems and in the fight against climate change .
As scientists pointed out a few months ago, the destruction of tropical forests is taking place at an alarming rate, mainly to make way for crops and livestock. However, once the nutrients present in these lands are depleted, it is common that they are finally abandoned. When this happens, and as the years go by, it could cause a natural regrowth of the forest that was once there.
To better understand this process, researchers at Wageningen University and Research in the Netherlands analyzed a total of 77 secondary forest sites located in the tropical regions of Central and South America, and in West Africa.
As the scientists stated, although most of the land had only been subjected to medium or low intensity agriculture (in which soil degradation did not become extreme), all the areas studied were in different stages of regrowth . This allowed the team to reconstruct what the forest recovery would look like over time.
In order to compare the recovery at the different sites, the team of scientists contrasted each secondary forest with nearby primary forests; with those forests that, ultimately, had not undergone major changes or disturbance. They found that the more similar the secondary forests were to nearby primary forests, the more they had recovered .
Thus, after 20 years , the average secondary forest that had grown from agricultural lands that were used with medium to low intensity, had recovered 78 percent of the attributes of primary forests, “much faster than we thought. ”, As the scientists indicated.
Of course, the researchers found a significant variation between the recovery time for the different attributes of the forest. For example, soils were the fastest to recover ; and most of the recovery was in the first decade.
However, it took 25 to 60 years for the diversity of plant species to recover .
All this would become a reason for hope that these forests could end up recovering naturally, something important if we take into account that secondary forests currently constitute more than 28 percent of the tropical blocks located in Central and South America, and they are important for sequestering carbon , crucial for tackling climate change.
