|Scientific Name:||Xanthocyparis vietnamensis|
|Species Authority:||Farjon & Hiep|
|Taxonomic Notes:||See Farjon et al. 2002. New genus and species in Cupressoid clade of family Cupressaceae, apparently closely related to one species in North America now placed with it in the new genus (X. nootkatensis, syn. Chaemaecyparis nootkatensis).|
|Red List Category & Criteria:||Endangered B2ab(iii,v) ver 3.1|
|Reviewer(s):||Farjon, A. & Xu, W.|
Xanthocyparis vietnamensis has previously been assessed as Critically Endangered on the basis of its very restricted extent of occurrence (EOO), area of occupancy (AOO) and continuing decline. The new localities that have been discovered since 1999 (Cao Bang, Tuyen Quang in Viet Nam and Guangxi in China) have extended its known EOO to about 16,000 km2 which is beyond the threshold for Endangered but within that for Vulnerable. However, while the new localities have increased its AOO beyond the 10 km2 threshold for Critically Endangered, it is still much less than the threshold for Endangered (<500 km2) . Although X. vietnamensis is now known from 5-6 locations, it is still considered to be severely fragmented. There is an ongoing decline in the quality of habitat and probably the number of mature individuals especially within the smaller subpopulations in Viet Nam. On this basis an overall assessment of Endangered under the criteria for B2 is warranted. A new assessment may be required if further subpopulations are discovered in China or Viet Nam.
|Range Description:||Xanthocyparis vietnamensis was originally discovered in the Bat Dai Son Mountains of northern Hagiang Province in Viet Nam. Since that discovery, very small subpopulations have also been found in two other provinces in northern Viet Nam (Cao Bang and Tuyen Quang). More recently a single tree has been reported from the Mulun Nature Reserve in Guangxi, China (Wei Bin Xu, Guangxi Institute of Botany, pers. comm. April 2012). The true extent of its distribution in China is currently unknown. Based on current information the extent of occurrence is estimated to about 16,500 km2. The area of occupancy is uncertain but it is assumed to be more than 10 km2 but much less than 500 km2. There are 5-6 locations and the subpopulations are severely fragmented.|
Native:China (Guangxi); Viet Nam
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||Surveys within Viet Nam indicate that the total number of mature individuals is probably between 500 and 1,000 with the majority in the Bat Dai Son area. To date, only a single tree has been recorded from Guangxi although it is highly probable that there are more. The overall population trend is thought to be declining.|
|Habitat and Ecology:||This small to medium sized tree (10-15 m) grows on the ridges and summits of karst limestone formations (very steep mountains) in elfin forest (cloud forest). In Guangxi it has been recorded from an altitude of 720 m a.s.l whereas in Viet Nam it generally occurs between 1,000 and 1,600 m a.s.l. It occurs together with other conifers (the dominant species is Pseudotsuga sinensis) and small-leaved angiosperms, numerous epilithic and epiphytic orchids, ferns, mosses, etc.|
|Use and Trade:||Locally used for house construction.|
|Major Threat(s):||Wood cutting is the main threat. The wood of Cupressaceous conifers, as well as its foliage, is sought after in eastern Asian culture. The lower slopes are being heavily deforested for the expansion of agriculture, but this is unlikely to reach the ridges. But firewood cutting and cutting for other purposes (this species produces a fine, yellow-brown very hard, fragrant timber) evidently does occur in some areas. Due to the lack of transport facilities and other factors, most of the timber has been traded locally. Estimates of population decline cannot be made at this stage given our current knowledge.|
|Conservation Actions:||In Viet Nam the majority of the national population occurs with the Bat Dai Son and Na Hang nature reserves. This species has also been added to Group IA of the National List of Rare and Precious Flora and Fauna which prohibits any exploitation. An ex situ conservation programme has been initiated and some restoration work undertaken in the Bat Dai Son area. In China, this species is only known from one nature reserve.|
Averyanov, L.V., Hiep, N.T., Harder, D.K. and Loc, P.K. 2002. The history of discovery and natural habitats of Xanthocyparis vietnamensis (Cupressaceae). Turczaninowia 5(4): 31-39.
Farjon, A. 2010. A Handbook of the World's Conifers. Koninklijke Brill, Leiden.
Farjon, A, Hiep, N.T., Harder, D.K., Loc, P.K. and Averyanov, L. 2002. A new genus and species in Cupressaceae (Coniferales) from northern Vietnam, Xanthocyparis vietnamensis. Novon 12(2): 179-189.
IUCN. 2013. IUCN Red List of Threatened Species (ver. 2013.1). Available at: http://www.iucnredlist.org. (Accessed: 12 June 2013).
Regalado Jr., J., Loc, P.K., Hiep, N.T., To, V.T. and Averyanov, L. 2006. The Vietnamese Golden Cypress (Xanthocyparis vietnamensis) Conservation Status Assessment (CSA) and Conservation Action Plan (CAP). Flora and Fauna International, Hoang Lien Son Project, Hanoi, Vietnam.
|Citation:||Thomas, P. 2013. Xanthocyparis vietnamensis. The IUCN Red List of Threatened Species. Version 2015.2. <www.iucnredlist.org>. Downloaded on 29 August 2015.|
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