A new study suggests that regrowing tropical forests may have shorter lifespans

Preventing the re-deforestation of secondary forests is a major challenge for restoration efforts in the tropics, according to a new study led by researchers at Columbia University, São Paulo University and Brazil's Federal University of ABC

Natural forest regeneration is considered a cost-effective strategy for countries to achieve their ecological restoration and carbon sequestration goals

The new study, published in Environmental Research Letters, quantifies forest regeneration in Brazil's Atlantic Forest and identifies factors that influence how long regenerated forests survive

The Brazilian Atlantic Forest is a rich natural area that originally covered 150 million hectares along the Atlantic coast

Using detailed land-use cover data from 1985 to 2019, the authors mapped and tracked the fate of more than 4.

"While the persistence of two-thirds of the regenerated forest area casts a positive outlook for the conservation of the ecoregion, the short lifespan of the regenerated forest presents new challenges for restoration work in the region," said Pedro Ribeiro Forum.

The ephemeral nature of these regenerated forests limits biodiversity and carbon storage benefits during regeneration, he said

"Given that forest cover increased in many tropical regions in the early 2000s, carbon sequestration through tropical reforestation and natural regeneration could make an important contribution to climate change mitigation," said senior author María Uriarte, director of Earth Research Columbia.

In a previous paper, Piffer and Uriarte found that without reversing reforestation, forests in Brazil's Atlantic Forest region could absorb 1.

"Our results underscore the dual challenge of forest conservation in the tropics, that we not only need to restore degraded areas, but we also need to ensure that these young persistently regenerate forests," said Jean Paul Metzger, professor of ecology at the University of São Paulo and the project Co-authors of the new study

Ensuring the sustainability of tropical forest regeneration is critical for countries to meet their recovery and carbon sequestration commitments under the Paris Agreement, the scientists noted

They also identified factors that may help protect regenerated forests

"Regenerating forests can take decades to restore pre-disturbance levels of species richness and biomass, so identifying conditions that allow these young forests to be more durable is critical for developing effective public policies to increase forest cover in Brazil's Atlantic Forest, is critical," Piffer said