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

Abstract

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.