Some 64,000 species of trees are known worldwide, but that’s nowhere close to the real number, according to a research project involving 100 scientists. In a paper in the Proceedings of the National Academy of Sciences, the scientists estimate 9,400 species are yet to be discovered.
“Our results indicate that there are (approximately) 73,000 tree species globally, among which (around) 9,000 tree species are yet to be discovered. Roughly 40 percent of undiscovered tree species are in South America,” said the paper. “Moreover, almost one-third of all tree species to be discovered may be rare, with very low populations and limited spatial distribution (likely in remote tropical lowlands and mountains).”
Researchers arrived at the estimate after combining two global datasets, the Global Forest Biodiversity Initiative and TREECHANGE. With that information, they used new statistical methods to estimate the total number of species at the biome, continental and global scales, including species yet to be discovered. A biome is a type of major ecological community, such as a savanna or a tropical rainforest.
“These results highlight the vulnerability of global forest biodiversity to anthropogenic changes, particularly land use and climate, because the survival of rare taxa is disproportionately threatened by these pressures,” said Peter Reich, a University of Michigan forest ecologist.
Reich and Purdue forest ecology professor Jingjing Liang were the senior authors of the paper.
“Tree species diversity is the key to maintaining healthy, productive forests, and it is important to the economy and environment,” said Liang.
The study, “The number of tree species on earth,” is available here.