Nearly 30% of tree species in the wild are threatened with extinction, new report says

Almost 30% of tree species in the wild are now at risk of extinction, with a wide range of factors responsible for their decline, according to analysis released Wednesday.

Published by Botanic Gardens Conservation International, the State of the World’s Trees report found that out of the planet’s 58,497 recorded tree species, 17,510 — or 29.9% — were threatened.

In addition, 4,099 are regarded as being “possibly threatened” while at least 142 species are now extinct in the wild, according to the report.

The figure of 29.9% does not assume that “data deficient” species, or those that scientists don’t have enough information on, are threatened. If all species in this category were deemed to be threatened, the percentage under threat of extinction would jump to 51.3%.

“Assuming that Data Deficient species are equally likely to be threatened as all other tree species, we can estimate that 38.1% of tree species are classified as threatened,” the report said. Conversely, 41.5% of species are not seen as being under threat. 

“The main threats to tree species are forest clearance and other forms of habitat loss, direct exploitation for timber and other products and the spread of invasive pests and diseases,” the report said. “Climate change is also having a clearly measurable impact.”

Expanding on the latter, a statement from BGCI said both climate change and extreme weather were “emerging threats to tree species globally.”

“As the temperature and weather of the world changes, many trees risk losing areas of suitable habitat,” it added. “This affects species in both temperate and tropical habitats, with Cloud Forest tree species of Central America being at particular risk.”

The report’s figures were based on data from various sources such as the International Union for Conservation of Nature’s Red List, scientific research papers and conservation assessments.

The trees under threat will be familiar to many and include oaks, magnolias and maples. 

Paul Smith, BGCI’s secretary general, said the report was “a wake up call to everyone around the world that trees need help.”

“Every tree species matters — to the millions of other species that depend on trees, and to people all over the world,” he said.

Trees are a crucial cog in the planet’s ecosystem, with a report from the Food and Agriculture Organization of the U.N. stating forests “supply water, mitigate climate change and provide habitats for many pollinators, which are essential for sustainable food production.” Elsewhere, the IUCN says forests absorb roughly 2.6 billion metric tons of carbon dioxide every year.

While the BGCI report makes for sobering reading, the organization also listed a number of actions that could be taken to “protect and bring back threatened species.”

These include: conserving threatened species in seed bank and botanic garden collections; increasing the availability of corporate and government funding for tree species under threat; the expansion of schemes focused on tree planting; and extending “protected area coverage for threatened tree species that are currently not well represented in protected areas.”

Among those commenting on Wednesday’s findings were Sara Oldfield, who is co-chair of the Global Tree Specialist Group.

“Trees are vital for our future and for a healthy world we need tree species diversity,” Oldfield, who also contributed to the BGCI report, said.

“Each tree species has a unique ecological role to play. With 30 percent of the world’s tree species threatened with extinction we need to urgently scale up conservation action.”