Response of fungal communities to fire in a subtropical peatland

Abstract

Purpose: Wild re, an increasing disturbance in peatlands, could dramatically change carbon stocks and reshape plant/microbial communities, with longlasting effects on peatland functions. Soil fungi are important in controlling the belowground carbon and nutrient cycling in peatlands; however, the impact of altered re regimes on these fungi is still unclear.Methods: Here we assessed fungal abundance, composition, and diversity across four soil depths (0-5 cm, 6-10 cm, 11-15 cm, 16-20 cm) under lowintensity and high-intensity re in a subtropical peatland in the southeastern USA.Results: Low-intensity re signi cantly increased fungal Shannon diversity and the saprotrophic fungal composition in the 0-5 cm soil layer immediately and then retracted within 2 years. Such hump-shaped pattern, however, were not observed in deeper soils. The dominant fungal class Archaeorhizomycetes declined initially and then returned to pre-low-intensity res levels at 0-5 cm depths. Time since low-intensity re was a primary driver of fungal composition in the 0-10 cm soil depth, while geographical distance among sites affected the deeper soils (11-20 cm). The fungal Shannon diversity failed to recover to the unburned state even after 30 years after high-intensity re, especially in 6-20 cm soil depths. Strati cation patterns of the fungal community was diminished by high-intensity re. Soil properties (either phenolics or carbon) were the primary drivers in shaping fungal community reassembly after highintensity re across all soil depths. Conclusion: Collectively, the fungal communities seem to be highly resilient to low-intensity re, but not to high-intensity re in our shrub bog peatlands.

All boreal forest successional stages needed to maintain the full suite of soil biodiversity, community composition, and function following wildfire

“…An unexpected taxon detected in our study, Archaeorhizomycete fungi, does not form above-ground sporocarps so are not typically known as a pyrophilous taxon, however, recent studies that have used DNA metabarcoding have found these fungi to be abundant following wildfire 38 , 71 . Archaeorhizomycete fungi were initially described from marker gene studies of soil, found to have a global distribution, and later two species were isolated as slow-growing cultures 72 – 74 .…”

“…Archaeorhizomycete fungi were initially described from marker gene studies of soil, found to have a global distribution, and later two species were isolated as slow-growing cultures 72 – 74 . In a study of soil fungi from a subtropical peatland, Archaeorhizomycete fungi had high relative abundance responding to low- and high-intensity fire at various soil depths 71 . Another study has specifically linked Archaeorhizomycete fungi with decreased soil water repellency and increased soil moisture content, following wildfire in a European pine stand 38 .…”

All boreal forest successional stages needed to maintain the full suite of soil biodiversity, community composition, and function following wildfire

“…An unexpected taxon identified in our study, Archaeorhizomycete fungi, does not form above-ground sporocarps so are not typically known as a pyrophilous taxon, however, recent studies that have used DNA metabarcoding have found these fungi to be abundant following wildfire. 39,72 Archaeorhizomycete fungi were initially described from marker gene studies of soil, found to have a global distribution, and later two species were isolated as slow-growing cultures. [73][74][75] In a study of soil fungi from a subtropical peatland, Archaeorhizomycete fungi had high relative abundance responding to low-and high-intensity fire at various soil depths.…”

“…[73][74][75] In a study of soil fungi from a subtropical peatland, Archaeorhizomycete fungi had high relative abundance responding to low-and high-intensity fire at various soil depths. 72 Another study has specifically linked Archaeorhizomycete fungi with decreased soil water repellency and increased soil moisture content, following wildfire in a European pine stand. 39 In this study, we detected Archaeorhizomyces SVs as bioindicators of establishment and mature stand development stages, representing the 11 th most abundant class of fungi based on relative read abundance.…”

The temporal and spatial response of soil fungal community composition and potential function to wildfire in a permafrost region in Canada

“…Both the soil properties and above‐ground vegetation can influence the soil fungal communities. With the forest recovery after fire, the above‐ground vegetation becomes progressively more diverse, and both the mixing of plant litter and the interaction of root exudates may be important factors causing significant changes in soil physicochemical properties, such as pH, which may lead to an altered fungal community and function (Glassman et al, 2017; Tian et al, 2021). The soil vertical gradient itself is an important determinant of fungal community composition and dispersal (Lindahl et al, 2007; Upton et al, 2020).…”