旅游踩踏对梵净山植物根系真菌群落的影响

The effects of tourism-related trampling on the root-associated fungal community of Fanjing Mountain

为探讨旅游踩踏对世界自然遗产地梵净山地区植物根系真菌群落的影响,在梵净山海拔1100,1500和2000m处设置极重度踩踏区、重度踩踏区、中度踩踏区、轻度踩踏区和未踩踏区,利用高通量测序技术分析植物根系真菌群落特征.结果表明:子囊菌门(Ascomycota)为优势真菌门,晶杯菌科(Hyaloscyphaceae)、皮盘菌科(Dermateaceae)、小蔓毛壳科(Herpotrichiellaceae)和球囊霉科(Glomeraceae)为优势科.中度踩踏区或轻度踩踏区植物根系真菌具有较高丰富度和多样性,旅游踩踏、海拔、旅游踩踏和海拔交互作用均显著影响植物根系真菌群落组成.海拔、旅游踩踏、根组织密度和叶生物量显著影响植物根系真菌丰富度,Shannon指数受海拔、旅游踩踏、比根长、根碳含量和叶生物量的显著影响.旅游踩踏、海拔、土壤全碳、土壤全磷、根碳含量、平均根直径、叶生物量和叶碳含量显著影响植物根系真菌群落结构,其中土壤和植物根叶碳磷含量对塑造真菌群落的贡献最大.

The aim of this study was to explore the responses of the root-associated fungal community to tourism-related trampling at different elevations on Fanjing Mountain.Extremely high trampling plots,high trampling plots,moderate trampling plots,light trampling plots and no trampling plots were established at 1100,1500 and 2000m,and root samples were collected in the plots by the point-centered-quarter method.The characteristics of root-associated fungal community were evaluated by high-throughput sequencing technology.Ascomycota was the dominant phylum,while Hyaloscyphaceae,Dermateaceae,Herpotrichiellaceae and Glomeraceae were the most abundant families.Higher fungal richness and diversity were found in the plots with moderate or light trampling,and two-way permutational multivariate analysis of variance showed that tourism-related trampling,elevation,and the tourism trampling×elevation interaction significantly affected the root-associated fungal community.The changes in root-associated fungal richness were mainly driven by elevation,tourism-related trampling,root tissue density and leaf biomass;elevation,tourismrelated trampling,specific root length,root carbon content and leaf biomass were the important factors influencing the Shannon index.The changes in tourism-related trampling,elevation,soil total carbon,soil total phosphorus,root carbon content,mean root diameter,leaf biomass and leaf carbon content significantly affected root-associated fungal community structure,and the nitrogen and phosphorus contents explained the vast majority of the differences in root-associated fungal community composition.