Aetoxylon sympetalum (Steenis & Domke) Airy Shaw (Thymelaeaceae) is a monotypic tree species endemic to West Borneo. It can reach a height of c. 30 m and grows mainly in inundated soils such as heath forests. The tree produces aromatic resin that smells similar to that of agarwood and that is extracted and mixed with resin from agarwood-producing trees of the genus Aquilaria. The market demand for A. sympetalum has increased as the demand for agarwood has risen. The species was formerly harvested in Indonesia but is now protected under the Minister of Environment and Forestry Decree 106/2018 because of its rarity, continuing decline and endemicity. Nationally, A. sympetalum has been categorized as Critically Endangered.
A research team from the Indonesian Plant Red List Authority, in collaboration with the National Agency for Research and Innovation, Natural Resources Conservation Agency West Kalimantan Province, and Tumbuhan Asli Nusantara Foundation, surveyed for A. sympetalum during July–August 2023 in Mentebah District of the Kapuas Hulu Regency of West Kalimantan Province. We collected data on the number of mature and immature individuals, area of occupancy, extent of occurrence and threats, and seedlings and twigs were collected for propagation in a nursery in West Java. The information obtained will be used to reassess the species’ conservation status and to estimate its standing stock. We found only nine mature and seven immature trees. Efforts to find other trees and propagation experiments are ongoing. We anticipate that the propagated cuttings will serve as planting stock for ex situ conservation.
During our surveys we informed local communities and village officials about the protected status of A. sympetalum. We also explained how the existence of A. sympetalum within a forest can be used as the legal basis for applying for land status as a customary forest.
We thank Re:wild, the IUCN Species Survival Commission for an Internal Grant, the Indonesian Scientific Authority–National Agency for Research and Innovation, and village leaders of Mentabah District.