At least 16,425 of the 47,282 species are at risk of extinction, according to the assessment.

"Today, we are releasing the global assessment of the world's trees on the IUCN Red List, which shows that more than one in three tree species are threatened with extinction. Trees are essential to support life on Earth through their vital role in ecosystems, and millions of people depend upon them for their lives and livelihoods," Dr. Grethel Aguilar, director general of the IUCN, said in a statement.