The Dipterocarpaceae—a family of tree giants that provide valuable timber for regional and international markets—are dominant members of the tropical forests of Southeast Asia. For the first time, through the Global Tree Assessment, more than 50 researchers across 15 organizations have collaborated to prepare IUCN Red List assessments for the 535 dipterocarp species. The findings were published on 3 March 2023 in The Red List of Dipterocarpaceae, which builds on national and regional assessments.

Occurring in 46 countries across four continents, 67% (357 species) of dipterocarps have been categorized as threatened, with 70 species categorized as Critically Endangered. One species, Hopea shingkeng, has been categorized as Extinct, and 22 species as Data Deficient because of their rarity or lack of recent records.

Southeast Asia is the centre of dipterocarp diversity, with Indonesia (278 species) and Malaysia (340 species) having the greatest number of species and also the highest number of threatened species, with 168 and 211 species at risk, respectively. Sri Lanka and India have far fewer species but > 90% of their native dipterocarp species are threatened. In total, 84% of the 201 dipterocarps endemic to a single country are at risk of extinction.

The primary reported threat is land conversion, affecting > 400 species, with the major conversion being for agroindustry. The second most significant threat is timber harvesting. These findings follow the global threats identified in the 2021 State of the World's Trees by Botanic Gardens Conservation International. In addition, threats posed by fire and climate change continue to increase. Threats are often synergistic, with instances of infrastructure development promoting logging and land-use change.

Conserving dipterocarp species is a global effort, with research and conservation actions being undertaken in various countries by research institutes, universities, government agencies, NGOs, botanic gardens and other organizations. Each country has its own story to tell and actions taken include sustainable forest management, site protection, species rescue and recovery planning, changes in law and policies, ex situ collections and many more.

The Red List of Dipterocarpaceae is a call for greater support of conservation activities from the wider plant and conservation community. There is a need for the mobilization of sustainable funding and collaborations to bring these forest giants and their habitats back from the brink.