Trees of the family Dipterocarpaceae are valued for their timber and resin. In Sumatra the family is represented by eight genera and c. 109 species and six subspecies, of which at least 11 species are endemic. One of these endemics, Dipterocarpus cinereus Sloot., was categorized as Extinct on the IUCN Red List in 1998. According to Ashton (Dipterocarpaceae. Flora Malesiana, Series I, 92, 237–552) this species is only known from the c. 8,000 ha Mursala (= Morsala, Moesala or Mansalaar) Island in the District of Tapanuli Tengah in North Sumatra Province. It was first collected in 1916 by A.V. Theunissen and described by Dirk Fok van Slooten under the name Dipterocarpus cinerea in 1927. In 1982 Peter Ashton asserted its name to be Dipterocarpus cinereus Sloot.
With the support of the Government of Indonesia through the Indonesian Institute of Sciences, Bogor Botanic Gardens carried out an expedition during March–April 2013 to survey for a possible remnant population of D. cinereus on Mursala Island. After more than 2 weeks the team found D. cinereus in at least two localities. However, we found only three mature trees, and several seedlings that we believe to be of this species. According to local people D. cinereus is a species targeted for its timber, along with other dipterocarp species such as Dryobalanops aromatica, Shorea spp. and Dipterocarpus caudatus ssp. penangianus.
Bogor Botanic Gardens is now carrying out further studies on the genetic variability of D. cinereus and other dipterocarp species found on the island. With the collaboration of the local people we are also planning to collect the fruits of D. cinereus, for propagation and future restoration of the species in the wild. Mursala Island is currently managed as a protected forest by the local government but we recommend that it receives improved protection, through the Ministry of Forestry.
