More than 9,000 tree species may be waiting to be discovered

Many of them are probably rare and hiding out in South America

an aerial view of a forest

Earth may be home to around 73,000 tree species, scientists now estimate.

Ricardo Lima/Moment/Getty Images Plus

Earth is home to a lot more types of trees than once thought.

Our planet hosts about 64,100 known tree species. Another 9,200 or more species might also exist, scientists now estimate. These just haven’t been found yet. If true, this would bring the total number of tree species on Earth to about 73,300.

To reach this new estimate, researchers analyzed global forest data. They used statistics to calculate how many species might exist. Then, they subtracted the number of species known to science. This gave them an estimate of how many novel species may still await discovery.

Roberto Cazzolla Gatti is a biologist at the University of Bologna in Italy. He and his team reported their findings February 8 in the Proceedings of the National Academy of Sciences.

More than a third of the unseen species may live in the Amazon region of South America. Any undiscovered trees there are likely rare, says Cazzolla Gatti.

His team’s new findings could help focus efforts to preserve the Amazon. Fires and logging are quickly erasing its habitat. Many plants and animals may be wiped off the map before they can be discovered.

Without biodiversity, Cazzolla Gatti argues, “we have not many chances to keep our planet alive.”