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ABSTRACT Ectomycorrhizal and saprotrophic fungi respond differently to changing edaphic conditions caused by atmospheric deposition. Within each guild, responses can vary significantly, reflecting the diversity of species and their specific adaptations to environmental changes. Metal contaminants are often deposited onto earth's surface through atmospheric deposition, yet few studies have assessed the relationship between soil metal contamination and fungal communities. The goal of this study was to understand how soil metal contamination and other edaphic factors vary across the spruce‐fir ecosystem in the Southern Appalachians and influence fungal diversity and function. Here, we characterize soil fungal communities using high‐throughput sequencing of the ITS2 gene region and found that higher soil lead (Pb) concentrations were associated with lower fungal diversity. Ectomycorrhizal fungi were less diverse (specifically hydrophilic ectomycorrhizal functional types) at plots with elevated soil Pb concentrations, while saprotrophic fungi were less diverse at plots with elevated soil carbon:nitrogen ratios. Fungal community composition was significantly influenced by pH, Pb, and spatial factors. This study identifies important relationships between fungal diversity and soil Pb concentrations and indicates variable responses of genera within well‐defined ecological guilds. Our work highlights the need to characterize poorly understood taxonomic groups of fungi and their function prior to further environmental degradation. 

Abstract Following disturbances such as wildfires, oak seedlings must form a symbiotic association with mycorrhizal fungi to survive. Wildfires, however, reduce available mycorrhizal fungal propagules in the soil. Ectomycorrhizal (ECM) fungi on oak seedlings sampled in severely burned (7 sites), moderately burned (7 sites), and unburned areas (8 sites) in the Great Smoky Mountains National Park were evaluated 21 months after the 2016 Chimney Tops 2 Wildfire by Sanger sequencing of the nuclear ribosomal DNA internal transcribed spacer region (nrITS; fungal barcode). Sequences were aligned and grouped into Operational Taxonomic Units (OTUs) based on well-supported phylogenetic clades and 98–100% nrITS sequence homology with sequences in GenBank. One hundred seventy-nine root-associated fungi comprising 124 OTUs were recovered after removing duplicates (the same fungus on two or more roots of the same plant). The ECM genusRussulawas the most diverse genus (25 OTUs), followed by theThelephora/Tomentellaclade (18 OTUs),Lactifluus(8 OTUs),Lactarius(4 OTUs), and Laccariaaff.laccata(2 OTUs).RussulaOTUs were identified more frequently on oak roots from burned areas and in burned soils, suggesting that someRussulataxa may have a selective advantage in burned areas. High alpha diversity occurred within each of the burn categories, but little overlap of taxa occurred between burn categories (high beta diversity). Approximately half of the recovered OTUs (100/179 total root-associated fungi = 55.9%) were found on a single plant. Oak seedlings growing in moderately and severely burned areas 21 months after a fire were capable of forming root associations with available fungi. In contrast to the expectation that root-associated fungal diversity would be reduced after a wildfire, diversity 1 year after the Chimney Tops 2 Fire was high with ectomycorrhizalLaccaria,Russulaceae, andThelephoraceaedominating. This study suggests that the availability of ECM fungi post-fire is not a barrier to oak re-establishment. 

Abstract Crepidotusis a genus of common saprotrophic fungi well known especially in the Northern Hemisphere, but distribution patterns of individual species are not sufficiently understood. We redefined a taxonomic circumscription ofCrepidotus cinnamomeusbased on morphological and molecular congruencies between the type material and recent collections. The species is well delimited from other similar and currently accepted species of the genus.Crepidotus cinnamomeuswas found to have a broad holarctic distribution with occurrences in North America, Europe and Asia where it grows on twigs and branches of deciduous trees and shrubs in preferably cold humid habitats. Here we present the first multilocus phylogeny of the genus, including portions of theRPB2gene. Our study highlights the importance of sufficient sampling from broader areas supported by sequence data, which is essential for estimation of species delimitation, distribution and correct name assignment forCrepidotusspecies.