More than 1,000 scientists took part in the assessment of the conservation status of trees, compiled by the plant conservation charity, Botanic Gardens Conservation International (BGCI) and the International Union for Conservation of Nature (IUCN).
Emily Beech of BGCI said 38% of the world’s trees are now threatened with extinction.
“Trees are highly threatened all across the world but now we have the tools that we need to make sure that we prioritise conservation action on the ground,” she said.
Trees are at risk in 192 countries, with clearing land for farming and logging the biggest threat and, in temperate regions, pests and diseases.
Well-known trees such as magnolias are among the most threatened, with oaks, maple and ebonies also at risk.