Tropical rainforests recover more than 90% of their biodiversity within 30 years of agricultural land abandonment, according to a study published in the scientific journal Nature, led by researcher Timo Metz and drawing on field observations from Ecuador’s Chocó region, a bioregion that extends directly into Colombia’s Pacific coast, placing the country’s 3.9 million hectares of secondary forest at the center of one of the most consequential ecological recovery findings in decades.
Recovery is possible, the study confirms, but the 90% figure carries a qualification that matters as much as the headline number itself.
What the research actually measured
The team analyzed more than 10,800 species across regenerating forest plots of varying ages, using three complementary techniques: bioacoustic monitoring (identifying animal species through the sounds they produce in the field), environmental DNA or eDNA analysis (detecting species presence through genetic traces they leave in soil and water), and AI-assisted data processing to cross-reference identifications across a dataset large enough to capture broad ecological patterns rather than isolated cases.
Species abundance and diversity, measured as how many individuals and how many distinct species a forest holds, recovered to over 90% of old-growth forest levels within three decades, while species composition, meaning the specific mix of original plant and animal species, reached only about 75% similarity to primary forest over the same period, with full compositional recovery taking several additional decades or, in some cases, centuries.
The breach between 90% abundance recovery and 75% compositional recovery reveals a story beyond the numbers: a regenerated forest can teem with life yet remain ecologically different from the one it replaced, because returning species numbers does not guarantee the precise biological relationships that define an old-growth ecosystem.
The engine of recovery and what it means for Colombia
Mobile species, including birds, bats, and bees, return early to regenerating forests and drive recovery by dispersing seeds and pollinating plants, effectively rebuilding the ecological scaffolding that allows slower-moving or habitat-specialist species to reestablish over longer timeframes, a mechanism the Nature study identifies as the central engine of the 90% rebound, and one that requires intact adjacent forest to supply those mobile species in the first place.
Colombia’s Instituto de Investigación de Recursos Biológicos Alexander von Humboldt documents 3.9 million hectares of secondary forest across the country, concentrated in the Caribbean lowlands, the Andean foothills, and the Pacific coast departments of Chocó, Valle del Cauca, and Nariño, which overlap directly with the Chocó bioregion where the study gathered its evidence, making recovery is possible not just a global finding but a statement about Colombian territory specifically.
Worth noting, a 2024 Nature study separately found that Colombia, alongside Brazil, China, Indonesia, and Mexico, holds 52% of the world’s potential for natural tropical forest regeneration, a figure that places additional scientific weight on the question of whether Colombia’s land-use policy allows that potential to be realized.
The condition the findings require
The Nature study specifies that recovery at the rates it documents depends on one prerequisite: that land use ceases and the forest regenerates without further clearing, a condition Colombia has not consistently met at the national scale, since the OECD’s Environmental Performance Review of Colombia, published in January 2026, found that primary forest loss in the Amazon continued to exceed recovery targets, with deforestation driven by cattle ranching, illicit crop cultivation, and road expansion persisting in the same departments where secondary forest recovery potential is highest.
Colombia committed under the 2022 Kunming-Montreal Global Biodiversity Framework to halt and reverse forest loss by 2030, and the Nature study’s 30-year recovery timeline fits precisely within a scenario where that commitment holds, but the OECD review’s documentation of ongoing deforestation suggests the gap between what Colombian forests can do and what Colombian land governance currently allows them to do remains the central variable in translating scientific optimism into ecological fact.