The research on how different irrigation amount affects the vegetation of degraded grassland

Based on the analysis about the results of a 3-year pasture plots irrigation experiment and 1-year monitoring after irrigation, which were done in Xilamuren grassland area, Inner Mongolia, we have concluded that:(1)irrigation can improve the production function of the grassland, but there is no much difference between the two different-amount irrigation plots (adequate and moderate irrigation). When stop irrigation, the vegetation of the two irrigated-plots degraded a little more and faster than the non-irrigation plot.(2)The species composition of two irrigation plots both have no obvious differences from non-irrigation plot. The two irrigated-plots´ Bray-curtis similarity coefficients were about 0.8 in the 3-year experiment. When stop irrigation, the adequate irrigation plot´s Bray-curtis similarity coefficients were 0.61 and the moderate irrigation plot´s were 0.55, which indicated that different irrigation amount have nearly the same affection on plant survival strategy.