| Juniperus tibetica | |
|---|---|
 | |
| Bundesarchiv Bild 135-S-05-06-08, Tibetexpedition, Landschaftsaufnahme | |
Scientific classification | |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Gymnospermae |
| Division: | Pinophyta |
| Class: | Pinopsida |
| Order: | Cupressales |
| Family: | Cupressaceae |
| Genus: | Juniperus |
| Species: | J. tibetica |
| Binomial name | |
| Juniperus tibetica | |
| Synonyms[2] | |
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Juniperus tibetica, theTibetan juniper, is a species ofjuniper, native to westernChina in southernGansu, southeasternQinghai,Sichuan, andTibet 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 elevationtreeline in the northern hemisphere.[5]
The highest known stand ofJ. tibetica was found at 29°42' N 96°45' E at 4900 m in southeastern Tibet (Xizang Autonomous Region, Baxoi County).[5]
It is anevergreenconiferousshrub or small to medium-sizedtree 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. Theleaves are of two forms, juvenile needle-like leaves5 millimetres (1⁄4 inch) long on seedlings and occasionally (regrowth after browsing damage) on adult plants, and adult scale-leaves1.5–3 mm (1⁄16–1⁄8 in) long on older plants; they are arranged in decussate opposite pairs orwhorls of three. Thecones are ovoid, berry-like,9–16 mm (3⁄8–5⁄8 in) long and7–13 mm (1⁄4–1⁄2 in) diameter, blue-black, and contain a singleseed; they are mature in about 18 months. The male cones are1.5–2 mm (1⁄16–3⁄32 in) long, and shed their pollen in spring. It is usuallymonoecious (male and female cones on the same plant), but occasionallydioecious (male and female cones on separate plants).[3][4]
It is the onlywoody plant occurring over large areas of high altitude Tibet, and grows very slowly in the harsh climatic conditions there. Thewood is therefore of major importance to local communities for building construction and fuel, and is also burnt forincense. The foliage is also heavily browsed by domesticgoats and otherlivestock.[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]
