Changes of community characteristics in the legume/grass pasture in different year after establishment

The experiment was conducted to measure the changes of species number, yield and community characteristics in the pasture where mixed with 6 species of gramineae or leguminosae and lied in the degraded meadow steppe of Zhaosu piedmont in Xinjiang, aiming to provide theoretical basis and practical experiences for the improvement of degraded rangelands and construction of artificial pastures. The results showed that the species composition and community structure changed fundamentally compared with the control. The planted species in the pasture occupied predominate position and its aboveground biomass was significantly higher than that of the control (P0.05). The maximum biomass (about 2 500 gm-2) appeared in the middle of July with over 15 days ahead of natural grassland, and it was 2.54 times than the control. The original grasses appeared successively resulting in species richness, diversity and evenness increased collectively along with the extension of years, and the important value of plant pasture declined. There was decline trend for the species of legume, but the species of grasses increased. The productivity in the pasture showed the trend of declination, however it maintained much higher.