Cleared land can return to tropical forest in just 20 years
In the face of rapid deforestation, especially in tropical areas, a recent study published in Science Magazine in 2021 brings promising news: tropical forests can bounce back remarkably quickly. Researchers found that cleared land can recover up to 80% of its original forest cover within 20 years if left alone.
Deforestation has serious consequences worldwide, leading to the loss of wildlife and worsening climate change. However, this new study shows that nature can heal itself if given the chance. Unlike replanting trees, natural regrowth lets ecosystems recover on their own. This method not only saves time and money but also supports a richer variety of plants and animals returning to their homes.
The researchers focused on the rate of regrowth in secondary forests, which are forests that naturally regenerate after human activities like agriculture or cattle ranching clear the land.
A team of over 90 researchers from around the world examined how various aspects of forests recover across 77 landscapes and 2,275 forest plots in tropical regions of the Americas and West Africa. They employed models to predict the recovery process using a technique called chronosequencing. Chronosequencing is a scientific method used to study ecological succession, particularly in the context of forest regeneration. It involves analyzing the changes in an ecosystem over time at different stages of development, known as chronosequences. Researchers collect data from sites of varying ages since disturbance, such as clear-cutting or fire, to understand how ecosystems recover and develop over time.
Their findings reveal that different aspects of the forest regenerate at varying speeds. Soil can bounce back to 90% of its pre-clearance condition in less than a decade, while plant function takes around 25 years to recover fully. Structural components and biodiversity typically return within 25 to 60 years, and biomass and species composition may take a little over a century. However, on the whole, the previously cleared land can revert to about 78% of its original state within just 20 years.
The impact of this discovery goes beyond restoring ecosystems. Tropical forests are crucial for trapping carbon dioxide, a key greenhouse gas. Speeding up their recovery could greatly help fight climate change by capturing more carbon naturally.
Faster forest regrowth can accelerate carbon capture and mitigate climate change through several mechanisms. Firstly, as forests regenerate, they actively draw down atmospheric CO2 as trees and other vegetation grow, absorbing carbon from the air and incorporating it into their biomass. This process of carbon sequestration can be particularly rapid in young, vigorously growing forests, where trees are actively photosynthesizing and accumulating biomass at a high rate.
Moreover, as forests mature, they continue to sequester carbon over time, albeit at a slower pace, by storing carbon in their woody tissues and organic matter in the soil. Older, more established forests may store vast amounts of carbon accumulated over decades or even centuries, making them crucial reservoirs of carbon storage and important buffers against rising atmospheric CO2 levels.
Additionally, tropical forests contribute to climate change mitigation by providing other ecosystem services that indirectly influence the carbon cycle. For example, intact forests help regulate regional and global climate patterns by influencing factors such as rainfall patterns, temperature regulation, and atmospheric moisture levels. These climatic conditions can, in turn, affect the carbon uptake and storage rate in forests, which will further influence their role in mitigating climate change.
By promoting the restoration and conservation of tropical forests, we can use their immense potential as natural climate solutions and contribute to global efforts to address climate change and biodiversity loss.
