关键词: 西藏, 沙漠化, 生物生产力, 物种多样性

Abstract: For determine the impacts of desertification on bio-productivity and species diversity in Tibet, we selected the typical desertification regions, the Shiquan River volley in Arli prefecture, the Jiangdang terrace in Xikaze city, and the eastern area of Cuona Lake in Anduo county, to investigate the species composition and the standing biomass. Analyzing results were obtained as follows: (1) The vegetation cover in the three typical desertified regions declined significantly in process of desertification, especial from potential desertified land to stabilized dunes or semi-stabilized dunes; (2) Standing biomass in the three typical desertified regions declined significantly in process of desertification, and all the perennial shrub species disappeared and replaced by annual herb at shifting dunes; (3) In the process of desertification, the Richness index values in the three typical desertified regions declined significantly, although the Shannon-Wiener index values showed different trend from potential desertified land to stabilized dunes and from semi-shifting dunes to shifting dunes, but all declined significantly from stabilized dunes to semi-shifting dunes.

Key words: Tibet, desertification, bio-productivity, species diversity