[An investigation on rare and endangered Tibetan medicinal plants in Lhasa region]

To investigate and study the endangered Tibetan medicinal plant species, their moisture content, biomass and resources reserves in Lhasa region.

The rare and endangered Tibetan medicinal plant resources were investigated by plot-quadrat method, walking and inquiry ways, sampling and drying method.

There were 37 species of rare and endangered plants, belonging to 22 families and 34 genera in Lhasa region. The moisture content of aerial part was higher than that of underground part in many plants. The moisture content of Przewalskia tangutica was the highest (91.97%), and the lowest one was Fritillaria delavayi (only 25.99%). The mean biomass of Rubus biflorus was the highest (1 830.480 g), that of Cordyceps sinensis was the lowest (0.291 g). The root-shoot ratio of Asparagus filicinus was the maximum (5.313), the minimum was Aconitum gymnandrum (0.286). The largest output was 18.000 kg x hm(-2) for Berberis agricola, the output of Saxifraga pasumensis was the lowest (0.007 kg x hm(-2)). The resources reserves of the rare and endangered plants were 15683.697 t in Lhasa region, the maximum was 7690.230 t for B. agricola, 49.03% of the total reserves, the minimum was 2.393 t for S. pasumensis, only 0.015%.

The characteristics of rare and endangered plants were as follows: abundant species and complex habitats, widely distribution but uneven, rich reserves and high economic value. We suggested to update the endangered level of medicinal plants, strengthen the scientific research on these plants, maintain sustainable utilization of the rare and endangered plants in Lhasa region.