Investigation and Evaluation of the Rare and Endangered Tibetan Medicinal Plants in the Linzhi Region
林芝地区珍稀濒危藏药植物资源调查与评价

Tibetan medicinal industry is one of six major pillar industries in Tibet autonomous region. The rare and endangered plants are increasingly and widely used in Tibetan medicinal industry; however, there has been lack of a clear understanding of these resources and their reasonable applications. In this study, the rare and endangered Tibetan medicinal plants distributed in the Linzhi region of Tibet were analyzed by the plot-quadrat method, walking and inquiry ways. In the investigation, 153 sample plots (30m×30m) and 1,377 quadrats (2m×2m) were set up in 51 typical sites, covering a total plot area of 137,700 m2. Results show that there were 35 species of rare and endangered plants, pertaining to 23 families and 33 genera in the Linzhi region. The ratio of species was high, and it was an epitome of plants distribution in Tibet. The moisture content of aerial part was higher than that of underground part in many plants except for Codonopsis convolvulacea, Mirabilis himalaica, Polygonatum cirrhifolium, Asparagus filicinus, Pterocephalus hookeri, Phlomis younghusbandii and Bupleurum marginatum var. stenophyllum. The mean biomass of Berberis Agricola was highest (1,800 g) and the lowest one was only 0.699 g for Polygonatum cirrhifolium. The biomass of aerial part was 14 times that of underground part for Herpetospermum pedunculosum, the ratio was the maximum, and the minimum ratio of them was 0.189 for Asparagus filicinus. Variations in biomass of aerial part, underground part, and the whole plant were similar for Polygonatum cirrhifolium, Halenia elliptica, Bupleurum marginatum var. stenophyllum and Veronica L. in the same latitude, but changes in the biomass showed different features, determined by plant height and density. The resources reserves of the rare and endangered plants were estimated to be 3,199.29 t in the Linzhi region. The biomass in unit area was closely related to altitude. Rare and endangered plants showed characteristics of abundant species and complex habitats, wide and uneven distribution, rich reserves and high economic value. Some suggestions are given as follows, e.g., dealing well with the relationship between resource protection and development, building ecological industry reserve on medical plant, strengthening scientific research on these plants and building the plantation, and determining the endangered level of medical plant. These results provide a theoretical basis for management and sustainable utilization of rare and endangered plants over the Linzhi region.