Responses of soil fungal communities and functional guilds to ~160 years of natural revegetation in the Loess Plateau of China

Abstract

Natural revegetation has been widely confirmed to be an effective strategy for the restoration of degraded lands, particularly in terms of rehabilitating ecosystem productivity and soil nutrients. Yet the mechanisms of how natural revegetation influences the variabilities and drivers of soil residing fungal communities, and its downstream effects on ecosystem nutrient cycling are not well understood. For this study, we investigated changes in soil fungal communities along with ~160 years of natural revegetation in the Loess Plateau of China, employing Illumina MiSeq DNA sequencing analyses. Our results revealed that the soil fungal abundance was greatly enhanced during the later stages of revegetation. As revegetation progresses, soil fungal richness appeared first to rise and then decline at the climax Quercus liaotungensis forest stage. The fungal Shannon and Simpson diversity indexes were the lowest and highest at the climax forest stage among revegetation stages, respectively. Principal component analysis, Bray–Curtis similarity indices, and FUNGuild function prediction suggested that the composition, trophic modes, and functional groups for soil fungal communities gradually shifted along with natural revegetation. Specifically, the relative abundances of Basidiomycota, Agaricomycetes, Eurotiomycetes, and ectomycorrhizal fungi progressively increased, while that of Ascomycota, Sordariomycetes, Dothideomycetes, Tremellomycetes, saprotrophic, pathotrophic, arbuscular mycorrhizal fungi, and endophyte fungi gradually decreased along with natural revegetation, respectively. The most enriched members of Basidiomycota (e.g., Agaricomycetes, Agaricales, Cortinariaceae, Cortinarius, Sebacinales, Sebacinaceae, Tricholomataceae, Tricholoma, Russulales, and Russulaceae) were found at the climax forest stage. As important carbon (C) sources, the most enriched symbiotic fungi (particularly ectomycorrhizal fungi containing more recalcitrant compounds) can promote organic C and nitrogen (N) accumulation in soils of climax forest. However, the most abundant of saprotrophic fungi in the early stages of revegetation decreased soil organic C and N accumulation by expediting the decomposition of soil organic matter. Our results suggest that natural revegetation can effectively restore soil fungal abundance, and modify soil fungal diversity, community composition, trophic modes, and functional groups by altering plant properties (e.g., plant species richness, diversity, evenness, litter quantity and quality), quantity and quality of soil nutrient substrates, soil moisture and pH. These changes in soil fungal communities, particularly their trophic modes and functional groups along with natural revegetation, impact the accumulation and decomposition of soil C and N and potentially affect ecosystem C and N cycling in the Loess Plateau of China.

Temperature sensitivity of organic carbon decomposition in lake sediments is mediated by chemodiversity

“…Firstly, Q 10 is expected to vary with changes in temperature (Davidson & Janssens, 2006), so the exploration of Q 10 along a temperature gradient could further reveal the response characteristics of decomposition to warming under fluctuating background temperatures. Secondly, only bacterial communities were considered in this study, whereas fungi may have a stronger effect than bacteria in utilizing refractory organic carbon (e.g., lignocelluloses and humus) by producing a wide range of extracellular enzymes (Alster et al., 2018; Peay et al., 2008; Yang et al., 2022). Therefore, we encourage the incorporation of multiple microbial taxonomic groups into studies of carbon decomposition and its temperature sensitivity.…”

Exploring the diversity and potential functional characteristics of microbiota associated with different compartments of Schisandra chinensis

“…In the present study, we examined the microbial communities in S. chinensis from different geographical locations, of different varieties, and in compartments with different ecological niches. The diversity and homogeneity of soil microbial community structure affect ecosystem stability; improve the ability of crops to respond to changes in the soil microbiological environment, particularly to pathogenic microorganisms; and enhance disease resistance of crops ( Yang S. et al, 2022 ; Yang J. et al, 2022 ). The alpha-diversity analysis showed that the diversity and homogeneity of the microbial community were higher than those of the microbial community in the rhizospheric soil samples of S. chinensis and showed a highly significant relationship between different compartments.…”

“…The Actinobacteriota includes many members of plant growth-promoting bacteria ( Dawkins and Esiobu, 2018 ); these members can degrade plant residues in soil and convert them into an inorganic form that is more readily absorbed by plants ( Wang X. et al, 2022 ; Wang Q. et al, 2022 ). Basidiomycota , a significantly enriched group of related fungi in leaves, can degrade low-quality substrates and recalcitrant lignin and lignocellulosic matrices ( Yang S. et al, 2022 ; Yang J. et al, 2022 ). Based on the random forest analysis, we identified marker species at the genus level in different S. chinensis samples.…”