Study on the characteristics of degradation succession of Elymus nutans community and its correlation to soil properties

The characteristics of degradation succession of Elymus nutans community and its correlation to soil properties were studied. The results showed that with the degradation succession of E. nutans community, the dominance of E. nutans decreased significantly, species richness and species diversities index increased significantly; grass functional group gradually declined, sedges and forbs functional group gradually increased. In late succession stage, the community tended to stable. The main features of the soil properties showed that all indicators gradually showed an increasing trend in addition to soil moisture and total phosphate, and particularly in the late succession stage, the contents of soil organic matter, total N, NH4+N，NO3-N, moisture bulky density significantly increased. The dominance persistence of E. nutans depended on the minimization of interspecific competition and sustained soil fertility level, and N played a leading role. The best time to supply N was in peak period or prepeak period of E. nutans dominance.