Abstract: Aimed at the severe degradation of spring- and autumn pastures in Yili River valley, an investigation was made on these pastures under different managements (fencing, irrigating, and fencing and irrigating), and their degradation causes and restoration strategies were discussed from the aspects of plant biomass, species composition, biodiversity, and proportion of high quality grass. The results showed that the plant biomass on the pastures under proper irrigation was 1 540.5 g·m^-2, while that without irrigation was 188.13 g·m^-2, indicating that drought was an important factor limiting the vegetation growth. However, it was not enough to only improve the water condition of the pastures under over-grazing. With an overloading rate of 123%, the proportion of high quality grass on the pastures under irrigation decreased from 62.38% with fencing to 2.08% without fencing. Therefore, moderate grazing supplemented with irrigation could be the prerequisite for the effective restoration of natural pasture in Yili River valley.

Key words: Phragmites communis, Rhizome, Age class, Bud bank, Bud flow model, Dry land habitat, Alkalinized meadow