Study on Characteristics of Soil Seed Bank of Natural Grassland in Nierong County

[Objectives] To explore the species, density, distribution and other characteristics of the soil seed bank of different degrees of degraded grassland in Nierong County, and introduce the species composition of the above-ground vegetation community. [Methods] The grassland in Nerong County was divided into non-degraded, mildly degraded, moderately degraded, and severely degraded grassland. Then the relationship between above-ground vegetation and soil seed bank and the role of seed bank in the construction of above-ground vegetation community was analyzed. [Results] The soil seed bank density of moderately degraded plots is the highest, and that of severely degraded grassland is the lowest. For the non-degraded and mildly degraded plots, the species in the soil seed bank are mainly Cyperaceae such as Kobresia pygmaea and Kobresia humilis. For moderately degraded plots, the species in the soil seed bank is dominated by Potentilla anserina in Rosaceae family. Besides, the soil seed bank of each plot is mainly concentrated in the 0-3 cm soil layer. The similarity between the soil seed bank and the vegetation community of the sample plots from high to low is: no degradation > mild degradation > moderate degradation > severe degradation. [Conclusions] In accordance with the present situation of grassland degradation, for moderately degraded grasslands, it is recommended to take appropriate enclosure and rest grazing; for severely degraded grasslands, no-tillage reseeding will be favorable for the restoration and protection of grassland ecological functions. In summary, it is intended to provide references for the management of alpine meadows and the restoration and reconstruction of degraded ecosystems in alpine regions.