There are 14% more tree species than previously thought, according to what researchers are calling the first “scientifically credible” estimate.
Of the 73,300 estimated species, the researchers predict there are 9,200 that are yet to be discovered.

But most rare species are in tropical forests, fast disappearing because of climate change and deforestation.
The study is based on a database of tens of millions of trees in more than 100,000 forest plots around the world.

The researchers used statistical techniques to predict the likely number of tree species, correcting for gaps in existing data.
The findings suggest more must be done to protect the incredible life forms needed for food, timber and medicine and to fight climate change by sucking carbon dioxide from the air.


Lead researcher Dr Peter Reich, of the University of Minnesota in St Paul, said the findings highlighted the vulnerability of global forest biodiversity.
“This is in the tropics and subtropics of South America, Africa, Asia, and Oceania and those are places where we discovered hotspots of known and unknown rare species.
