黄土丘陵区退耕还林对土壤真菌群落的影响

Effect of the Process of Returning Farmland to Forest in the Loess Hilly Area on Soil Fungal Communities

退耕还林显著影响了黄土高原土壤细菌群落结构与组成特征.然而,作为土壤微生物群落的重要组成部分,黄土高原土壤真菌落结构与组成特征如何响应退耕还林并不十分清楚.以山西省右玉县贾家窑黄土高原缓坡丘陵为研究区域,以耕地(玉米地和糜子地)和人工林地(沙棘林和柠条林)土壤为研究对象,通过18S rRNA高通量测序技术,研究了退耕还林对土壤真菌群落结构与组成特征的影响.结果发现,黄土高原丘陵区耕地和林地土壤中子囊菌门(Ascomycota)占绝对优势(61.03%~78.06%),毛霉门(Mucoromycota)次之(12.11%~17.13%),担子菌门(Basidiomycota)再次之(6.15%~18.42%),壶菌门(Chytridiomycota)等其余真菌门的相对丰度较低.退耕还林显著降低了子囊菌门的相对丰度而增加了担子菌门的相对丰度.属分类水平下,退耕还林显著影响了毛壳菌属(Chaetomium)、被孢霉属(Mortierella)、镰刀菌属(Fusarium)和地舌菌属(Geoglossum)等的丰度.镰刀菌属(Fusarium)等植物病原性真菌在耕地土壤中被富集.非度量多维尺度分析(NMDS)和相似性分析(ANOSIM)结果表明,退耕还林显著影响了黄土高原丘陵区土壤真菌群落结构与组成.群落结构的差异与土壤理化性质的变化密切相关,特别是有效磷是影响土壤真菌群落结构和组成变化的主要驱动因子.研究结果能够为黄土丘陵退耕还林区植被恢复的生态效益评价提供丰富的数据和科学参考.

The conversion of farmland to forest significantly affects soil bacterial communities in the Loess Plateau.However,how soil fungal communities respond to the conversion of farmland to forest is not very clear in this region.To illustrate the problem,the loess hilly area located in Jiajiayao,Youyu County,Shanxi Province was taken as the study area,and soil from farmland(growing corn and millet)and artificial forest(growing sea buckthorn and Caragana)were sampled.Based on 18S rRNA high-throughput sequencing,the effect of the conversion of farmland to forest on soil fungal communities was investigated.Ascomycota dominated(61.03%-78.06%)in both farmland and forest soil,followed by Mucoromycota(12.11%-17.13%)and Basidiomycota(6.15%-18.42%).The relative abundance of other fungal phyla,such as Chytridiomycota,was low.At the genus level,the conversion of farmland to forest significantly affected the abundance of Chaetomium,Mortierella,Fusarium,and Geoglossum.Plant pathogenic fungi belonging to Fusarium were enriched in farmland.The results of non-metric multidimensional scaling(NMDS)and analysis of similarity(ANOSIM)showed that the conversion of farmland to forest significantly affected soil fungal communities in the hilly area of the Loess Plateau.Differences in the community structure were closely related to changes in soil physicochemical properties.Available phosphorus was particularly the main driving factor affecting soil fungal communities.These results can provide scientific references for the ecological benefit evaluation of vegetation restoration in the loess hilly area.