Changes in composition and diversity of fungal communities along Quercus mongolica forests developments in Northeast China

Abstract

A better understanding of fungal community composition and diversity and their dynamic patterns driving forces under different successional forest will contribute to the maintenance and preservation of natural ecosystems. The aim of this study was to compare soil fungal communities and soil microbial activities among three successional temperature Quercus mongolica forest stands (20, 30 and 40 years old) in Northeast China to investigate the maintenance mechanism of fungal diversity and provide the basic theory basis for the functions of fungus in nutrient cycle. Based on the sequences of rRNA with Illumina Miseq, 508 different fungal phylotypes were identified and grouped into Ascomycota, Basidiomycota, Chytridiomycota, Glomeromycota and Zygomycota. Russula was the dominant genus in these three successional stages of Q. mongolica forests. Fungal communities differed across these three stands and the fungal diversity and richness was significantly lower in the 30 years stand than in the 20 years and 40 years stands. Meanwhile, a total of 93 ectomycorrhizal fungus (EMF) phylotypes were observed and the EMF diversity was similar across the three successional stands. The activity of soil urease increased with forest development ages and cellulase activity first decreased and then increased from 20 years stand to 40 years stand. Both nitrogen mineralization and nitrification were the lowest in September in the 30 years stand and reached the maximum value in August. Both soil net N mineralization and N nitrification were the lowest in 40 years forest stage in October. The Redundance analysis showed that fungal community was strongly affected by stand ages and environmental factors and the nine plots in the three successional forest stands were significantly clustered across successional forest stands. The dominant Lachnum in Ascomycota positively, while the dominant Russula in Basidiomycota negatively, correlated with total P, available P, Soil organic carbon (SOC), NO3−-N, soil moisture or pH. Our results could provide insights into relationships between taxonomic fungal diversity and soil chemical properties along different stages of forest. The findings also imply the functions of soil fungi in sustaining soil biogeochemical cycling were driven by the secondary succession in temperate ecosystems.