Dipterocarpus retusus 

Scope: Global
Language: English

Translate page into:

Taxonomy [top]

Kingdom Phylum Class Order Family
Plantae Tracheophyta Magnoliopsida Theales Dipterocarpaceae

Scientific Name: Dipterocarpus retusus Blume
Dipterocarpus tonkinensis A.Chev.
Dipterocarpus trinervis Blume

Assessment Information [top]

Red List Category & Criteria: Endangered A2cd ver 3.1
Year Published: 2017
Date Assessed: 2017-02-24
Assessor(s): Ly, V., Nanthavong, K., Pooma, R., Luu, H.T., Nguyen, H.N., Vu, V.D., Hoang, V.S., Khou, E. & Newman, M.
Reviewer(s): Chua, L.S.L.
Contributor(s): Barstow, M.
Facilitator/Compiler(s): Rivers, M.C.
Dipterocarpus retusus is a large tree species. It is found in the lowland montane evergreen forests of western China, India, Indochina, Malaysia and Indonesia. The species is globally assessed as Endangered. It is estimated there has been between a 50 and 70% population reduction in the last three generations (300 years) and decline will continue at a lower rate. The species is threatened by continued habitat loss and decline in habitat quality. The species is also at risk from over exploitation from the timber trade. The species is found in some protected areas but is not well represented in ex situ collections. It is recommended these be improved. The species also requires further habitat protection. It is further recommended that population decline, habitat decline and trade and harvest of the species be monitored.
Previously published Red List assessments:

Geographic Range [top]

Range Description:This species is native to Asia. It is found from India, across Indochina and into the Chinese states of Xizang and Yunnan. The species is also found on the islands of Indonesia. It is found from 300 m asl to 1,500 asl and it has an estimated extent of occurrence (EOO) exceeding 4 million km2.
Countries occurrence:
Cambodia; China (Tibet [or Xizang], Yunnan); India (Arunachal Pradesh, Assam, Nagaland); Indonesia (Jawa, Lesser Sunda Is.); Lao People's Democratic Republic; Malaysia (Peninsular Malaysia); Myanmar; Thailand; Viet Nam
Additional data:
Lower elevation limit (metres):300
Upper elevation limit (metres):1500
Range Map:Click here to open the map viewer and explore range.

Population [top]

Population:The species has a wide native range but within this the trees are scattered and rare. It is reported to grow gregariously within its Indian range (Singh et al. 2014) but is rare within Yunnan (Xiwen et al. 2007). It has a generation length of 100 years, There has been between a 50 and 70% population reduction  in the last three generations (300 years) due to the expansion of agricultural areas and exploitation for timber. The species is continuing to decline but at a lower rate.
Current Population Trend:Decreasing
Additional data:

Habitat and Ecology [top]

Habitat and Ecology:This large tree species can grow up to 50 m tall (Singh et al. 2014). It grows in wet evergreen lowland and montane forest. Within Malaysia it is found within oak (Quercus sp.) forests (Chua et al. 2010). It can be found in pure stands but more commonly is within mixed forests. The species habitat is currently in decline in both extent and quality.
Continuing decline in area, extent and/or quality of habitat:Yes
Generation Length (years):100

Use and Trade [top]

Use and Trade: This tree is used for timber (Mark et al. 2015). It belongs to the genus Dipterocarpus which produce commercially valuable medium hardwood and have the trade name Keruing. Within India the wood is commonly used in the production of plywood, tea chests, packing cases and railway sleepers (Singh et al. 2014) and within Yunnan the timber is used for building houses (Xiwen et al. 2007). The species can also be tapped for oleoresins which can be used for caulking boats and to make torches. The species is found within plantations in Indonesia (Weiland 1998) and also in public gardens throughout its distribution.

Threats [top]

Major Threat(s): This species is threatened by habitat loss and fragmentation. Its native habitat is continuing to decline in area, extent and quality due to clearance for the expansion of agriculture. The species is also at risk from selective logging for its timber.

Conservation Actions [top]

Conservation Actions: This species is reported from only two ex situ collections (BGCI 2017). Further ex situ collections of this species should be made which are representative of the species entire range. The species occurs in protected areas. The species is assessed as Least Concern within Malaysia (Chua et al. 2010). Within China Dipterocarpus retusus var. macrocarpus is assessed as VU and D. retusus car. retusus is assessed as Endangered (CMEP 2013). Dipterocarpus species are considered a priority species for conservation in many of the countries in this species native range (Luoma-aho et al. 2003). For example, within Indonesia Dipterocarpus spp. are only harvested once they are at least 50 cm in diameter (Masripitan et al. 2003). It is recommended the remaining individuals be subject to in situ conservation action. The species habitat requires protection and there should be an assessment of the species genetic diversity and structure. It is also recommended that population and habitat decline be monitored alongside the monitoring of species harvest and trade, which should also be restricted.

Citation: Ly, V., Nanthavong, K., Pooma, R., Luu, H.T., Nguyen, H.N., Vu, V.D., Hoang, V.S., Khou, E. & Newman, M. 2017. Dipterocarpus retusus. The IUCN Red List of Threatened Species 2017: e.T32400A2817693. . Downloaded on 27 April 2018.
Disclaimer: To make use of this information, please check the <Terms of Use>.
Feedback: If you see any errors or have any questions or suggestions on what is shown on this page, please provide us with feedback so that we can correct or extend the information provided