The Red List of Acer: revised and extended, was published in September 2020 by Botanic Gardens Conservation International (BGCI). It gave the conservation status of 158 Acer species. The report shows that one in five maple species (36 species) are at high risk of extinction and in need of conservation action, with 75% of threatened species geographically restricted in the wild. The report highlights that over a third of maple species are subject to loss of habitat as a result of urban development and increased agriculture. Timber harvesting is also a major threat, impacting a quarter of threatened maple species.