Taxonomic, functional, and phylogenetic diversity of fungi in a forest-tundra ecotone in Québec

Abstract

We quantified the taxonomic, functional, and phylogenetic diversity of fungi associated with dead moss tissues and conifer needles in a forest-tundra ecotone in a sub-Arctic region, Quebec, Canada. We detected 615 operational taxonomic units, in total, of fungi in 84 families with 97% sequence similarity by metabarcoding the internal transcribed spacer 1 (ITS1) region of nuclear ribosomal DNA. Saprotrophs were the dominant functional guild. The results indicated the effects of host plant species and local environmental heterogeneity on fungal diversity in the cold region. Taxonomic and phylogenetic diversity indices of fungal communities were significantly greater in moss than in conifers. The greater phylogenetic diversity in moss was mainly attributable to the presence of families in Mucoromycota, compared to those in conifers, in which relatively closely related families of Dikarya were present. The taxonomic diversity was also related to local variations in vegetation and soil properties, suggesting that the local colonization and establishment of vegetation and the concomitant development of soil contributed to the taxonomic diversity of fungi. In contrast, functional diversity was not significantly affected by the host, vegetation, or soil properties, indicating that the fungal community members were relatively redundant in terms of the evaluated functional traits.