地形对杉木林土壤酚酸物质含量及微生物群落结构影响

Effects of Terrain on Soil Phenolic Acids Content and Microbial Community in Cunninghamia Lanceolata Forest

地形是影响土壤酸酸类物质含量及微生物结构组成的主要因子之一,研究酚酸物质在不同地形中的变化规律及其与微生物群落结构的关系,有助于更好地揭示不同地形下土壤微生物群落结构变化潜在调控机制。以往研究主要集中于地形对微生物群落结构影响,而关于地形对土壤酚酸物质累积及其微生物群落结构间相互影响的研究鲜有报道。以福建省南平市100 a年生杉木林为研究对象,测定西南坡地、西北坡地、山凹地和山洼地上酚酸物质含量和土壤理化性质,并结合16S和ITS技术分析不同地形中土壤细菌和真菌群落结构的变化规律。结果表明:(1)不同地形土壤酚酸物质含量大小规律总体表现为西北坡地>西南坡地>山凹地>山洼地;随着土层深度加深,酚酸物质含量总体呈下降趋势。(2)西南坡地细菌放线菌纲相对丰度较高,山凹地真菌粪壳菌纲相对丰度较高;随土层深度加深,微生物相对丰度总体上呈降低趋势。(3)高浓度酚酸物质对细菌类浮霉菌纲和α-变形杆菌纲相对丰度起促进作用,而对放线菌纲和β-变形菌纲相对丰度起抑制作用;低浓度酚酸物质条件下真菌类粪壳菌纲和座囊菌纲相对丰度较高,而伞菌纲和定耳银纲相对丰度较低。(4)不同地形条件下,细菌群落结构表现较为分散,而真菌群落结构表现较为集中;土壤总孔隙度、土壤容重、水杨酸戊酯、有机质和阿魏酸对细菌群落影响显著,而全磷对真菌群落影响显著。不同地形导致土壤酚酸物质含量和微生物群落结构发生改变,酚酸物质对微生物具有双重作用,高浓度酚酸物质促进细菌菌类生长,而低浓度则会抑制真菌类生长。研究结果揭示土壤酚酸物质对微生物群落结构的影响,可为实现杉木林的长期生产力维持提供参考。

Terrain influences soil phenolic acids and microbial community.Investigation on the changes in phenolic acids compositions and their relationship with soil microbial community structures under different terrains can contribute to a fine understanding of mechanisms of resulting microbial community changes.Previous studies mainly concerned about the effects of terrains on microbial community structures,but no related work had been performed on the interaction between soil phenolic acids accumulation and microbial community structures in varied terrains.In this study,a hundred years of Cunninghamia lanceolata forest in Nanping,Fujian province,China,was targeted as case study.The phenolic acids and chemical properties were analyzed;16 s and ITS were used to determine the community structures of bacteria and fungus in four types of terrain soils,including southwest slope,northwest slope,corrie and valley.Results show that:(1)Phenolic acids content showed a trend of northwest slope>southwest slope>corrie>valley,and acids content decreased with the increase of soil depth;(2)The relative abundance of bacteria Actinomycetes was highest in southwest slope,and that of fungi Sordariomycetes was highest in corrie;The relative abundance of microorganisms decreased with the increase of soil depth.(3)In bacteria,the relative abundance of Planctomycetacia andα-Proteobacteria were the highest at high phenolic acids content,whereas the relative abundance of Actinobacteria andβ-Proteobacteria were the lowest;In fungus,the relative abundance of Sordariomycete and Dothideomycetes were higher at lower phenolic acids content,whereas the relative abundance of Agaricomycetes and Tremellomycetes were lowest.(4)The bacterial community structure was scattered in different terrains,whereas the fungal community structure was more concentrated.Total soil porosity,soil bulk density,amyl salicylate,soil organic matter and ferulic acid had significant effect on bacterial community,and total phosphorus had significant effect on fungal community.Different terrains lead to the change of phenolic acids content and microbial community structures.Phenolic acids had a dual function on microorganisms,including the promotion of bacteria growth caused by high content,and the inhibit of fungi growth caused by low content.The results revealed that the effects of soil phenolic acids on the microbial community structures,which could provide reference for the long-term productivity of Cunninghamia lanceolata forest.