Abstract: The degraded artificial grassland in the Qinghai Lake area was used as a research object to investigate the effects of organic fertiliser application on the interactions between different species in the soil microbial community and the functional characteristics of the species. The results showed that the application of organic fertiliser significantly altered the forage cover and soil physicochemical properties of degraded artificial grassland (P<0.05). It also altered the species composition and structure of the soil microbial community of the grassland. For the bacterial community,the application of organic fertilizer reduced the relative abundance of Chloroflexi,Balneolaeota,Spirochaetes and Candidatus Saccharibacteria (P<0.05),and increased the relative abundance of Gp7 and Acinetobacter (P<0.05);while the change in the relative abundance of fungal communities was not significant. The unilateral network structure showed a more complex and tighter relationship after organic fertiliser application and altered the core species in the microbial grid structure of artificial grasslands.The results of this study suggest that the application of organic fertiliser has a greater impact on soil microbial community structure and species interactions in degraded artificial grasslands,and the results of this study provide important insights into establishing changes in microbial dynamics in the restored grasslands.

Key words: Degraded artificial grassland, Organic fertilizer, Microbial diversity, Community structure, Unilateral networks

摘要： 以环青海湖地区的退化人工草地为研究对象,探究施有机肥对土壤微生物群落中不同物种之间的相互作用以及物种功能特征的影响。结果表明:施有机肥显著改变了退化人工草地植被盖度及土壤理化性质(P<0.05)。同时,也改变了草地土壤微生物群落物种组成和结构,对细菌群落而言,施有机肥降低了绿弯菌门(Chloroflexi)、巴纽尔斯菌门(Balneolaeota)、螺旋体门(Spirochaetes)和Candidatus Saccharibacteria的相对丰度(P<0.05),增加了Gp7和不动杆菌属(Acinetobacter)的相对丰度(P<0.05),而对真菌群落相对丰度的改变不显著。单边网络结构在施用有机肥后表现出更为复杂和紧密的关系,且改变了人工草地微生物网络结构中的核心物种。本研究结果表明施用有机肥会对退化人工草地土壤微生物群落结构以及物种相互作用产生更大的影响、提供了建立恢复草地微生物动态变化的重要见解。

关键词: 退化人工草地, 有机肥, 微生物多样性, 群落结构, 单边网络