Juniperus tibetica, the Tibetan juniper, is a species of juniper, native to western China in southern Gansu, southeastern Qinghai, Sichuan, and Tibet Autonomous Region, where it grows at high to very high altitudes of 2,600–4,900 metres (8,500–16,100 feet).[3][4] This species has the highest known elevation treeline in the northern hemisphere.[5]
| Juniperus tibetica | |
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| Bundesarchiv Bild 135-S-05-06-08, Tibetexpedition, Landschaftsaufnahme | |
Scientific classification 
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| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Gymnospermae |
| Division: | Pinophyta |
| Class: | Pinopsida |
| Order: | Cupressales |
| Family: | Cupressaceae |
| Genus: | Juniperus |
| Species: | J. tibetica
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| Binomial name | |
| Juniperus tibetica | |
| Synonyms[2] | |
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The highest known stand of J. tibetica was found at 29°42' N 96°45' E at 4900 m in southeastern Tibet (Xizang Autonomous Region, Baxoi County). [5]
It is an evergreen coniferous shrub or small to medium-sized tree growing to heights of 5–15 m (16–49 ft), rarely 30 metres (98 ft), with a trunk up to 2 metres (6+1⁄2 ft) in diameter. The leaves are of two forms, juvenile needle-like leaves 5 millimetres (1⁄4 inch) long on seedlings and occasionally (regrowth after browsing damage) on adult plants, and adult scale-leaves 1.5–3 mm (1⁄16–1⁄8 in) long on older plants; they are arranged in decussate opposite pairs or whorls of three. The cones are ovoid, berry-like, 9–16 mm (3⁄8–5⁄8 in) long and 7–13 mm (1⁄4–1⁄2 in) diameter, blue-black, and contain a single seed; they are mature in about 18 months. The male cones are 1.5–2 mm (1⁄16–3⁄32 in) long, and shed their pollen in spring. It is usually monoecious (male and female cones on the same plant), but occasionally dioecious (male and female cones on separate plants).[3][4]
Conservation and uses
editIt is the only woody plant occurring over large areas of high altitude Tibet, and grows very slowly in the harsh climatic conditions there. The wood is therefore of major importance to local communities for building construction and fuel, and is also burnt for incense. The foliage is also heavily browsed by domestic goats and other livestock.[3][4] Both uses have resulted in a significant decline in the species' abundance; formerly listed (1998) as not threatened,[6] it has more recently (2005) been re-categorised as Near Threatened.[4]
References
edit- ^ Farjon, A. (2013). "Juniperus tibetica". IUCN Red List of Threatened Species. 2013: e.T42256A2967451. doi:10.2305/IUCN.UK.2013-1.RLTS.T42256A2967451.en.
- ^ The Plant List: A Working List of All Plant Species, retrieved 11 February 2017
- ^ a b c Adams, R. P. (2004). Junipers of the World. Trafford. ISBN 1-4120-4250-X.
- ^ a b c d Farjon, A. (2005). Monograph of Cupressaceae and Sciadopitys. Royal Botanic Gardens, Kew. ISBN 1-84246-068-4.
- ^ a b Miehe, Georg; Miehe, Sabine; Vogel, Jonas; Co, Sonam; La, Duo (2007). "Highest Treeline in the Northern Hemisphere Found in Southern Tibet". Mountain Research and Development. 27 (2): 169–173. doi:10.1659/mrd.0792. hdl:1956/2482. S2CID 6061587. Retrieved 30 August 2017.
- ^ Conifer Specialist Group (1998): Juniperus tibetica