关键词: 青藏高原三江源, 人工建植草地, 管理模式, 土壤微生物群落, ASVs的相对丰度

Abstract:

Grassland reconstruction is a major approach to alleviate the ‘black beach’ in Sanjiangyuan of the Qinghai-Tibetan Plateau. It is vital to understand how to manage the planting grassland after reconstruction. And which artificial grassland management pattern is more likely to restore the degraded grassland of ‘black beach?’ To provide the scientific basis for the restoration of ‘black beach’, we investigated the changes in vegetation characteristics, soil physicochemical properties and soil microbial community structure of planting grassland under different management patterns, and explored the effect of the management patterns on community succession of planting grassland. In this study, vegetation characteristics and soil physicochemical properties were measured by field investigation and laboratory analyses, respectively. Soil microbial community composition was determined by high-throughput sequencing techniques. The results showed that there were significant differences in vegetation characteristics, soil physicochemical properties and soil microbial community structure of the planting grassland under different management patterns. Actinobacteria and Basidiomycota were mainly controlled by vegetation plant species diversity, aboveground biomass (AGB) and soil organic carbon (SOC). Shannon-Wiener index, AGB and SOC peaked and the relative abundance of amplicon sequence variants annotated by Actinobacteria and Basidiomycota were significantly enriched under the management pattern of the planting once treatment. Additionally, the soil had the highest bacterial diversity and the lowest fungal diversity under the planting once treatment, becoming a ‘bacterial’ soil. These vegetation characteristics and soil environment were more conducive to overall positive community succession, indicating that the planting once treatment is the most reasonable management pattern for restoring the ‘black beach’.

Key words: Sanjiangyuan of Qinghai-Tibetan Plateau, planting grassland, management pattern, soil microbial community, the relative abundance of ASVs