亚热带4种林分土壤真菌群落结构及功能

Structural and functional characteristics of soil fungal communities under 4 subtropical forest stands

【目的】探究亚热带地区不同林分类型土壤变化特征及真菌群落结构和功能差异,为该地区人工林和次生林的营林管理及土壤养分研究提供理论参考。【方法】利用高通量测序技术,对亚热带典型人工林杉木和马尾松,以及次生林甜槠和针阔混交林的土壤真菌群落结构、功能差异及其与土壤理化性质的相互关系进行分析。【结果】4种林分的土壤优势真菌门类群为担子菌门和子囊菌门,优势真菌科为红菇科与蜡伞科。土壤真菌群落的α多样性表现为杉木人工林>马尾松人工林>混交林>甜槠林;群落的β多样性在4种林分中存在显著差异。对于真菌功能群,杉木林与其他3种林分的土壤真菌的优势营养模式具有显著差异。杉木林以腐生营养型为主,其次为共生营养型,病理营养型比例最低;而马尾松林、甜槠林和混交林主要以共生营养型为主,其次是腐生营养型,病理营养型比例最低。在以共生营养型为主的林分中,马尾松林的真菌共生营养型相比阔叶林和混交林减少,而病理营养型增加。土壤pH、速效钾(AK)及铵态氮(NH+4)是影响土壤真菌群落结构和功能的主要因素。【结论】不同林分类型土壤真菌群落结构和功能特征差异明显,并与土壤因子密切相关。

【Objective】Exploring the characteristics of soil changes and differences in fungal community structure and function among different forest types in subtropical regions,providing theoretical references for afforestation management and soil nutrient research in artificial and secondary forests in the region.【Method】The structure and function of soil fungal communities under 4 typical subtropical forest stands[(plantations of Cunninghamia lanceolata(Lamb.)Hook.(CL)and Pinus massoniana Lamb.(PM),secondary forest of Castanopsis eyrei(Champ.)Tutch.(CT),and coniferous and broad-leaved mixed forest(MF)]were studied by Illumina MiSeq high-throughput sequencing technology.And their interrelationships with soil physicochemical properties were also analyzed.【Result】The dominant soil fungal phyla under the 4 stands were Ascomycota and Basidiomycota,and the dominant families were Russulaceae and Hygrophoraceae.Theαdiversity of soil fungal community followed the order of CL>PM>MF>CT,and theβdiversity differed significantly among the 4 stand types.For fungal functional groups,the dominant trophic mode of soil fungi under CL differed significantly from the other 3 stands.Under CL stand,saprophytic trophic mode was dominant,followed by symbiotic mode and pathotrophic mode.By contrast,PM,CT and MF stands were dominated by symbiotic trophic mode,followed by saprophytic mode and pathotrophic mode.Compared with CT and MF forests,the proportions of symbiotic and saprophytic fungi under PM stand decreased,while that of pathotrophic fungi increased.Soil pH,available potassium and ammonium nitrogen were the main factors influencing the structure and function of soil fungal communities.【Conclusion】This study showed that the structure and functional characteristics of soil fungal communities differ significantly between different stand types and are closely related to soil factors.