|Scientific Name:||Glyptostrobus pensilis|
|Species Authority:||(Staunton ex D.Don) K.Koch|
Thuja pensilis Staunton ex D.Don
|Red List Category & Criteria:||Critically Endangered C2a(i) ver 3.1|
|Assessor(s):||Thomas, P., Yang, Y., Farjon, A., Nguyen, D. & Liao, W.|
|Reviewer(s):||Nguyen, T.H. & Phan, K.L.|
Glyptostrobus pensilis was formerly very widespread in China, Viet Nam and possibly Lao PDR. In China and Viet Nam most of the natural plants have been killed due to expanding agriculture. It appears that there are no plants remaining in the wild in China and that the only remaining natural subpopulations are in Viet Nam and Lao PDR. Although the total number of trees is more than 250, very few, if any are producing viable seed and the majority of trees in Viet Nam are in decline. The species is therefore listed as Critically Endangered under criterion C. It could possibly also meet this under criterion A, but it is not known over what time period the greatest population reduction took place (it could well have been a long slow process exceeding three generations). Given current trends this species could well become Critically Endangered (Possibly Extinct in the Wild) in the near future.
|Previously published Red List assessments:||
|Range Description:||This species is found in SE China: Fujian, S Hunan, Guangdong, Guangxi, Jiangxi (it is suggested that most if not all of these supposed occurrences are cultivated plants (Li and Xia 2004, 2005) – there are more than 200,000 mature individuals known in cultivation); introduced on Hainan Island and in Sichuan, possibly natural in SE Yunnan (but this too is disputed). This species is known from nine small localities in Dac Lac province in in Viet Nam (Averyanov 2009). These represent two locations sensu IUCN. Recently several small stands were discovered in Khammouan Province, Lao PDR (Thomas and LePage 2011) - these are considered to represent one location sensu IUCN.|
Native:China (Fujian - Present - Origin Uncertain, Guangdong - Present - Origin Uncertain, Guangxi - Present - Origin Uncertain, Hainan - Present - Origin Uncertain, Jiangxi - Present - Origin Uncertain, Sichuan - Present - Origin Uncertain, Yunnan - Present - Origin Uncertain); Lao People's Democratic Republic; Viet Nam
|Estimated area of occupancy (AOO) - km2:||12|
|Continuing decline in area of occupancy (AOO):||Yes|
|Extreme fluctuations in area of occupancy (AOO):||No|
|Estimated extent of occurrence (EOO) - km2:|
|Continuing decline in extent of occurrence (EOO):||Yes|
|Number of Locations:||3|
|Lower elevation limit (metres):||500|
|Upper elevation limit (metres):||700|
|Range Map:||Click here to open the map viewer and explore range.|
No wild plants are known to remain in China, although hope remains that a few individuals may still survive.
In Viet Nam fewer than 300 trees occur in five localities. Three of these localities have less than 10 trees each. The main stands are located within Earal and Trap Kso nature reserves. No viable seed has been collected from these trees over the last 20 years (Averyanov et al. 2009)
In Lao PDR six stands were recently located during surveys of the Nakai plateau. The largest of these was inundated at the completion of the Nam Theun II hydroscheme. The total number of trees remaining is estimated to be less than 100 (Thomas and LePage 2011).
Although the total number of trees is more than 250, very few have been known to produce viable seed or to reproduce vegetatively. Within the context of the IUCN definitions, the number of mature individuals is less than 250.
|Current Population Trend:||Decreasing|
|Habitat and Ecology:||A heliophilous species, intolerant of competition and usually growing in pure stands or solitary along streams. In China it is mainly found on river floodplains and in deltas, always near or in water, where it develops a buttressed base and occasionally pneumatophores; also extensively planted along rivers and canals. In Viet Nam and Lao PDR it occurs along streams and in seasonally inundated areas at altitudes between 500 and 700 m asl.|
|Continuing decline in area, extent and/or quality of habitat:||Yes|
|Generation Length (years):||50|
|Use and Trade:||The rather soft, yellowish wood is like most cupressaceous wood decay resistant and finds uses in China ranging from furniture to building of bridges. The wood of the roots is very light and due to its buoyancy it is used in China to make life-saving rings. This species is widely cultivated in southern China and planted along rivers and canals as well as in parks; except for the latter localities mostly to harvest the timber followed by replanting. In Viet Nam wood is highly valued for crafts and is reputed to have anti-cancer properties although there is no scientific evidence to support this.|
In China and Viet Nam habitat loss due to intensive agriculture has been the main cause of decline. The subpopulations in Viet Nam are within coffee plantations, the water table has been altered and the trees are no longer producing fertile seed. Illegal logging of live and dead trees within the nature reserves has recently been reported.
|Conservation Actions:||Surveys are required of all potential areas of suitable habitat in China to see if any wild plants still remain. The subpopulations in southern Viet Nam and Lao PDR should receive urgent site protection and restoration efforts are required to increase the size and viability of these subpopulations. If that is not done this species could well become Critically Endangered (Possibly Extinct in the Wild).|
|Citation:||Thomas, P., Yang, Y., Farjon, A., Nguyen, D. & Liao, W. 2011. Glyptostrobus pensilis. The IUCN Red List of Threatened Species 2011: e.T32312A9695181. http://dx.doi.org/10.2305/IUCN.UK.2011-2.RLTS.T32312A9695181.en . Downloaded on 05 October 2015.|
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