Taxonomic, functional, and phylogenetic diversity of fungi along primary successional and elevational gradients near Mount Robson, British Columbia

Abstract

The taxonomic, functional, and phylogenetic diversity of fungi associated with dead leaves of alpine and subalpine plants were quantified along primary successional and elevational gradients in Mount Robson Provincial Park, British Columbia, Canada, to test the sensitivity of fungal diversity, functioning, and community assembly to environmental changes in a cold region. A total of 330 fungal operational taxonomic units were detected by metabarcoding of the internal transcribed spacer (ITS) region of nuclear ribosomal DNA, and among them saprotrophs were the dominant functional guild. Terrain age at the glacier foreland and plant taxa of dead leaves significantly affected taxonomic and phylogenetic diversity indices. The increase in values of standardized effective size of the mean nearest taxon distance as a phylogenetic diversity index of fungal communities suggested a shift from phylogenetic clustering to phylogenetic overdispersion in fungal communities after the glacier retreat. The elevation, which ranged from 874 m to 1668 m above sea level, did not affect the taxonomic, functional, or phylogenetic fungal diversity. Studying phylogenetic and functional diversity as aspects of fungal diversity provided useful insights into novel assembly and functional patterns of fungi in a cold region that could not be detected only by observing taxonomic diversity.