Time is Running Out for Maple Trees

The Botanic Gardens Conservation International (BGCI) revised its ‘Red List of Acer’ — the category of trees and shrubs that are commonly known as maples — and highlighted an elevated threat for 36 species of the tree. Seven are critically endangered, 14 are endangered, and 15 are vulnerable to extinction.

Knocked Down by Disease

The trees are experiencing a vast decline in habitat, due to urban development, timber harvesting, and agricultural expansion. "Time is running out for the world’s biodiversity,” said Douglas Justice, associate director at the University of British Columbia Botanical Garden.

“Every recent survey of plants and animals in the wild points to this. And as robust as Acer species are, they are certainly not immune.” He continued, “This is happening nearly everywhere that rarer maples exist. And because of climate change, the narrow habitats that support species at the margins of arid places and at the tops of mountains are quickly disappearing.”

Where?

The trees can be found in subtropical and tropical regions, as far south as Indonesia. The only species found in the UK, the field maple is not under threat. Not only are the trees a popular ornamental feature in parks and public spaces, they are a key component of the natural ecosystem in woodlands, as well as being an important timber crop in several countries.

Although the North American sugar maple, which produces maple syrup, is not endangered, two of the closest relatives to the species are.

China is home to the largest proportion of maples with 92 species. It has seen a number of trees become endangered due to urban sprawl. Some 14 of the 23 Acers at risk of extinction in the country are only found in China and have small populations and limited geographical ranges."We still have an opportunity to save species from extinction, but it will take expertise and resources, and the co-ordinated, collaborative efforts by the world’s botanical gardens to make it work," Justice added.

The Game Plan

The report notes that conserving at-risk species in their natural habitat is the best conservation tactic. But collections in botanical gardens and seed banks — called “ex situ collections” can act as insurance policies against extinction. There are currently 14 species of maple, including four that are critically endangered, that are absent from these types of collections.

One species in Mexico, the Acer binzayedii, is in “desperate need of conservation” despite only being discovered in 2017. “It is at risk from climate change in its remnant cloud forest habitat and threatened by grazing, logging, and forest fires while it is also absent from ex situ collections,” the report adds. The report recommends developing conservation plans, monitoring species currently not at risk to ensure populations are maintained, and adding those missing maple species to seed banks and the like.

BGCI is now establishing a Global Conservation Consortium (GCC) for the Acer trees to address the conservation needs of maple species. Through the consortium, maple specialists will work together to develop comprehensive strategies to manage and deliver conservation action points for the species.