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Description |
Geographic Range [top]
Range Description: Recorded from China (Guizhou (Xingyi) and Yunnan provinces); northern Viet Nam (Bac Can, Ha Giang, Ha Tuyen, Lao Cai, Nghe An and Thanh Hoa provinces) and recently in Houaphan Province, Laos PDR (Thomas et al. 2007, Gao et al 2016).
Countries occurrence:
Native:
China (Yunnan); Lao Peoples Democratic Republic; Viet Nam
Additional data:
? Lower elevation limit (metres): 800
? Upper elevation limit (metres): 1600
Range Map: Click here to open the map viewer and explore range.
Population [top]
Population: Remaining populations are small and threatened.
Current Population Trend: Decreasing
Additional data:
? Continuing decline of mature individuals: Yes
? Population severely fragmented: Yes
Habitat and Ecology [top]
Habitat and Ecology: Amentotaxus yunnanensis is usually a small understorey tree occurring scattered in mixed evergreen and deciduous broad-leaved forests, but occasionally it can become much larger and reach into the canopy of primary closed evergreen tropical rainforest. The altitudinal range is between 800 m and 1,600 m a.s.l. Annual precipitation is above 1,500 mm and fog is frequent. It is most commonly found on limestone karst formations, where it mixes with other conifers, e.g. Fokienia hodginsii, Xanthocyparis vietnamensis (locally), Pseudotsuga sinensis, Tsuga chinensis, Podocarpus neriifolius, Dacrydium elatum and Taxus chinensis, as well as with angiosperms. On substrates derived from silicious rocks (granite, gneiss) it is sometimes a large tree amongst angiosperms, with only a few associated conifers e.g. Cephalotaxus mannii, Dacrycarpus imbricatus and Nageia wallichiana. It is a relatively shade tolerant species, with seedlings and saplings successfully growing up under a forest canopy.
Systems: Terrestrial
Continuing decline in area, extent and/or quality of habitat: Yes
Generation Length (years): 25
Use and Trade [top]
Use and Trade: The timber of larger trees is valued for furniture making, while smaller sizes are used for handicrafts and tool making. Much of this is done in China and it is likely that timber of Vietnamese origin is used. The seeds are rich in oils and these are extracted for medicinal purposes. Screening for anti-cancer drugs, as in other species like Amentotaxus agrotaenia, may be conducted with this species as well, now that it is known to occur more widely. This species is in limited cultivation, e.g. as a bonzai plant.
Threats [top]
Major Threat(s): Due to recent discoveries made of this species during intensive botanical surveys in Viet Nam, this species is now known to have a wider distribution than previously assumed. The majority of its (sub)populations appear to be in Viet Nam, not in China, and it is also in Viet Nam where the species attains large tree size. A re-assessment for Viet Nam gave it the status of Vulnerable (VU) for that country. In China it has been given the status of Endangered (EN); this has lead to a similar global status as for the previous narrower concept of the species, based on the earlier assumption that most subpopulations were within that country. It is threatened mainly by deforestation, leading to fragmented areas of forest with declining population size in most. Targeted logging removes seed-producing trees, which may lead to diminished recruitment of seedlings and saplings in the population.
Conservation Actions [top]
Conservation Actions: Only a small proportion of the total distribution of this species occurs within protected areas and it has been observed that this is often insufficient to protect the species from deforestation or logging. Has been recorded from Xiaqiaogou in Xichou Xian, NW Yunnan (China) and from the Hoang Lien Son Nature Reserve (Viet Nam).
Citation: Thomas, P., Gao, L. & Phan, K.L. 2017. Amentotaxus yunnanensis. The IUCN Red List of Threatened Species 2017: e.T118076066A96812158. http://dx.doi.org/10.2305/IUCN.UK.2017-2.RLTS.T118076066A96812158.en. Downloaded on 18 October 2018.
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