Amazon forest recovery driven by few tree species

A small group of tree species drives much of the Amazon rainforest's recovery after land is cleared and then abandoned, according to a Brazilian study.

Fernando Elias, a researcher at the Emilio Goeldi Museum of Para and lead researcher on the study, said 15 to 25 species do most of the work in regenerating forest and storing carbon in recovering areas, despite the Amazon having thousands of tree species.

The study, published in July in the peer-reviewed journal Global Change Biology, examined secondary forests that emerge in razed areas of the Brazilian Amazon. The researchers used data from recovering forests in four regions of eastern Amazonia, covering more than 25,000 trees and palms. Some areas had been regenerating for one year, while others had been recovering for up to 60 years.

Elias said the pioneer species can grow quickly, tolerate poor soil and direct sun, and create shade that allows species found in mature primary forests to arrive. He said temperatures under the canopy of these core species can be reduced by up to six degrees Celsius.

The dominant species included Cecropia palmata, Inga alba, the Inaja palm and the babassu palm. Elias said their falling leaves increase organic matter in the soil and help begin forest recovery.

The study said the Amazon has an area of secondary forests the size of Uruguay. Elias said understanding which species dominate carbon stocks and ecosystem function could help make restoration faster.

Brazil has pledged under its Paris Agreement commitments to restore 12 million hectares of land. Data from Brazil's National Institute for Space Research says an area roughly the size of Spain has been deforested in Brazil over the past four decades.