Responses of fungal communities along a chronosequence succession in rhizosphere-associated soils of a tailing dam

Abstract:

Heteropogon contortus phytoremediation was changed by the fungal communities in the surface and rhizosphere soils of a tailing dam, which significantly impacted ecological carbon (C) and nitrogen (N) cycling. So far, the relationship between soil fungal communities and environmental factors is still poorly understood along a chronosequence (i.e., 0-year-old, 5-year-old, 10-year-old,15-year-old, 20-year-old, 25-year-old, 30-year-old, 40-year-old, 50-year-old) of Heteropogon contortus phytoremediation in a span of 50 years, while microbial community diversity increases along with time series of Heteropogon contortus phytoremediation. The dominant Dothideomycetes (20.86 %), Agaricomycetes (18.09 %), and Arthoniomycetes (1.69%) in rhizosphere soils were relatively higher than those in topsoil (13.9%, 2.65%, and 0.20%) at class level. Fungal spearman correction analysis by phylum was conducted to detect whether microflora was related to soil physical-chemical properties affecting the composition of fungal communities along with the Heteropogon contortus phytoremediation. The TN, AN, NO₃^--N, NO₂^--N and NH₄⁺-N indicators of the nitrogen cycle in the rhizosphere soil were significantly higher than those in the surface soil and the highest level has occurred in the 50-year-old Heteropogon contortus phytoremediation. The relative abundance of plant pathogen, wood saprotroph, dung saprotroph, and Arbuscular Mycorrhizal showed an upward tendency in rhizosphere soil along with the Heteropogon contortus phytoremediation.