华北退化荒地建植豆类和禾本植物人工草地对土壤真菌群落结构和功能的影响

Effects of artificial grassland establishment via legume and grass plants on the structure and function of soil fungal community in a degraded wasteland of Northern China

阐明植被恢复过程中土壤真菌群落的变化及其生态功能,对于制定科学有效的退化生态系统管理措施有重要参考价值。利用扩增子高通量测序技术和生物信息学分析解析了华北退化荒地自然恢复(对照组,CK)和建植豆科植物和禾本植物人工草地(分别为LG和GG处理)过程中土壤真菌群落结构和功能群特征差异。结果表明:(1)退化荒地土壤表层样品中共获取6315个真菌OTU,隶属于17门60纲145目347科896属,优势菌门为Ascomycetes、Mortierellomycota和Basidiomycetes,LG处理相较于CK的Basidiomycetes相对丰度明显升高,GG处理相较于CK的Mortierellomycota相对丰度明显提高。(2)土壤真菌功能群类型以腐生真菌为主,共生真菌次之,病原真菌占比最少。建植人工草地对腐生真菌和共生真菌相较于病原真菌的功能群组成影响更明显,并导致腐生真菌相对丰度升高,共生真菌相对丰度降低。(3)土壤真菌群落结构受植物物种丰富度、根系生物量等植被参数变化的显著(P<0.05)影响,且与土壤有机碳、总氮、速效氮、总磷等土壤养分水平显著(P<0.05)相关。本研究的结果有助于深入理解建植人工草地对土壤真菌群落结构和功能的影响,并为华北退化荒地植被恢复策略提供理论依据。

Elucidating the changes in soil fungal communities and their ecological functions during vegetation restoration is an important reference value for developing scientific and effective management measures of the degraded ecosystems.This study aims to reveal the effects of artificial grassland establishment via legume and grass plants on the structure and functional groups of soil fungal community in a degraded wasteland of Northern China.Using high⁃throughput amplicon sequencing and bioinformatics analysis,the differences of soil fungal community structure and functional group characteristics in natural restoration(control group,CK)and artificial grassland establishment via legume and grass plants(LG and GG treatments,respectively)of degraded wasteland in Yanqing county,Beijing were analyzed.The results showed that:(1)6315 operational taxonomic units(OTUs)were collected from soil surface samples of the degraded wasteland,belonging to 17 phyla,60 classes,145 orders,347 families,and 896 genera.The dominant phyla were Ascomycetes,Mortierellomycota and Basidiomycetes,and they accounted for 73.3%—99.6%of the total amount of soil fungi from each samples.The relative abundance of Ascomycetes and Basidiomycota presented opposite patterns of change in each treatment sample.Compared with CK,the relative abundance of Basidiomycetes in LG treatment was remarkably higher than that in CK.The relative abundance of soil nutrient indicator taxa Mortierellomycota in GG treatment was remarkably higher than that in CK,and this coincided with the fact that soil nutrients in GG treatment was highest among all treatments.The number of soil fungal biomarkers in the samples treated by LG was the highest.(2)Prediction of microbial functional groups based on FUNGuild software was conducted,and saprophytic fungi was the main functional group of soil fungi,followed by symbiotic fungi,and pathogenic fungi accounted for the least proportion.Compared with pathogenic fungi,the establishment of artificial grassland had more obvious influence on the functional group composition of saprophytic fungi and symbiotic fungi,and led to the increase in the relative abundance of saprophytic fungi and decrease in the relative abundance of symbiotic fungi.(3)Soil fungal community structure was significantly(P<0.05)affected by vegetation parameters such as plant species richness and root biomass,and significantly(P<0.05)correlated with soil nutrients such as soil organic carbon,total nitrogen,available nitrogen,and total phosphorus.The results were helpful to understand the influence of artificial grassland on the structure and function of soil fungal community,and provided theoretical basis for vegetation restoration strategy of the degraded wasteland in Northern China.