藏北一年生人工草地弃耕不同年限的土壤微生物群落特征研究

Study on Soil Microbial Community Characteristics of Annual Artificial Grassland Abandoned for Different Years in Northern Tibet

探讨人工草地弃耕对高寒草甸土壤微生物群落的影响,可为藏北高寒草地生态保护提供理论参考。分别采集弃耕2年、弃耕10年的人工草地和天然草地表层(0~10 cm)土壤样品,采用高通量测序技术分析土壤微生物群落组成和多样性变化。结果表明:土壤细菌群落独有OTUs表现为天然草地(5416)>弃耕2年(5057)>弃耕10年(3933),真菌群落独有OTUs表现为弃耕10年(1638)>弃耕2年(1564)>天然草地(1266)。不同弃耕年限土壤微生物群落多样性无显著差异。细菌群落(门和属水平)组成的主要影响因子为土壤pH值、有机质含量和速效氮含量,真菌群落门水平主要影响因子为土壤速效氮含量、pH值、速效磷含量和有机质含量,属水平主要影响因子除上述因子外还包括速效钾含量。总之,微生物群落组成与土壤因子密切相关。

The influence of artificial grassland abandonment on soil microbial communities in alpine meadows was investigated to provide theoretical references for ecological conservation in the northern Tibetan Plateau.Surface soil samples(0-10 cm)were collected from artificially abandoned grasslands after 2(R02)and 10(R10)years,as well as from natural grasslands.High-throughput sequencing technology was employed to analyze the composition and diversity of soil microbial communities.The results showed that the number of unique operational taxonomic units(OTUs)in bacterial communities followed the order of natural grassland(NG,5416)>R02(5057)>R10(3933),and the unique OTUs of fungal community were R10(1638)>R02(1564)>NG(1266).No significant differences were observed in soil microbial community diversity among the different abandonment periods.Soil pH,organic matter content,and available nitrogen content were the main factors influencing bacterial community composition at the phylum and genus levels,while available nitrogen content,pH,available phosphorus content,and organic matter content were the main factors influencing fungal community composition at phylum level.Additionally,the factors influencing fungal community composition at the genus level also included available potassium content,in addition to the aforementioned factors.In conclusion,soil microbial community composition is closely associated with soil factors.