News published 02 April 2025

The IUCN Red List of Threatened Species was updated last week (27th March) to include an additional 892 tree species, bringing the total number of tree assessments published to 47,817. Highlights from the update include many assessments for Cuba, Ecuador and New Zealand.

This latest update also includes assessments for species of Boswellia (frankincense trees) on Socotra Island, Yemen. One of the most valuable commodities of the ancient world, indigenous people continue to use the resin and bark of Boswellia species in traditional medicine and religious practices. Of the tree species published five have moved from Vulnerable to Endangered (Boswellia elongata, B. ameero, B. dioscoridis, B. bullata and B. popoviana), one from Vulnerable to Critically Endangered (Boswellia nana) and one has been assessed as Critically Endangered for the first time (Boswellia scopulorum). The species are threatened by increased foraging pressure from grazing goats, and more frequent and intense droughts, cyclones, flash floods and landslides. These assessments once again emphasise that tropical islands host the highest proportion of threatened tree species worldwide.

“Frankincense trees symbolise the uniqueness of Socotran biodiversity and the status of the island as a World Heritage site. But, like many other tree species around the world, these iconic trees face several threats, in particular from livestock. Since 2020, Fondation Franklinia has been supporting work on the ground by local dedicated people using several approaches to protect the seedlings. To save these species, it is urgent to reduce grazing impacts and focus on traditional sustainable grazing practices” said Jean-Christophe Vié, Director General of Fondation Franklinia, which has supported the Boswellia Red List assessments and conservation action for these species.

As assessment work continues, the IUCN SSC Global Tree Specialist Group (GTSG) has also been planning their strategy for 2026-2029 (the next IUCN quadrennium). From March 9-10th, The Morton Arboretum’s Centre for Species Survival for Trees (CSS: Trees) co-hosted a workshop with the Global Tree Specialist Group. Twenty GTSG members from 8 countries participated to develop the specialist group’s work and plan targets that will be implemented over the next four years for global tree conservation.