Preliminary assessment of large mammals in the Namcha Barwa region of south-eastern Tibet.
The region has a monsoon climate, and old-growth forests which span several vertical zones: tropical monsoon forest from 560 to 1100 m altitude - Terminalia myriocarpa, Lagerstroemia minuticarpa, Garcinia morella, Sloanea sinensis, Fissistigma oldhamii as well as understorey trees; subtropical montane broadleaved forests from 1100 to 2500 m - Quercus tungmaiensis, Castanopsis xizangensis, C. lamellosa, with Alnus nepalensis and Betula utilis on lower slopes and valley bottoms; from 2500 to 3000 m, coniferous forests occur - Pinus yunnanensis, Tsuga dumosa and Picea likiangensis; from 3000 to 3700 m, Abies delavayi predominates; alpine shrubs cover slopes between 3700 and 4000 m, and the treeline may extend to 4200 m, depending on local topography and soil conditions. The wildlife survey assessments (made in April-May and September-October 1994) indicated that wildlife populations appeared to be low except in inaccessible areas. Frequent reports of tiger predation on cattle, horses and mules in glaciated valleys on the S. slope of the Himalayas may indicate a shortage of natural prey. Uncontrolled hunting, human population growth and expedient economic development threaten the survival of large mammals in the region.