The Global Conservation Consortium for Acer is currently divided into the following operational regions:
Mexico and Central America
There are eight Acer taxa which occur in Mexico and Central America, including two Critically Endangered species: A. binzayedii and A. skutchii. The genus reaches its southernmost point in the Americas in Honduras, where it is represented by A. negundo subsp. mexicanum. Several taxa in the region have fragmented distributions and in need of conservation action.
Over 90 Acer species occur in China, with a quarter of these threatened in the wild. The centre of diversity for the genus is southwest China, where several species are threatened by habitat loss.
Japan and the Korean Peninsula
Japan is home to 26 Acer species, of which three are threatened with extinction. These include Acer amamiense (CR), which is currently understood to have less than 10 trees remaining in the wild.
11 Acer species occur on the Korean Peninsula, with two threatened species, A. okamotoanum and A. takesimense (both VU), which are both endemic to the island of Ullung-do.
Around 20 Acer species occur in southeast Asia, though several are insufficiently recorded. Acer calcaratum (VU) has a disjunct population, occurring in parts of Laos, Thailand and Vietnam, as well as in China and further west in Myanmar, though its distribution is not well understood. Two threatened species, A. chiangdaoense and A. pseudowilsonii (both EN), are endemic to Thailand.
Western Asia and Caucasus
There are around 18 Acer species native to western Asia and the Caucasus. Two Turkish endemics are threatened with extinction: A. divergens (VU) and A. undulatum (CR), as are two recently described species from northern Iran: A. iranicum (CR) and A. mazandaricum (EN).
United States, Canada and Europe
There are around 13 Acer species native to the United States and Canada, and around 12 native to Europe. None are currently considered threatened with extinction.