Data from: Substantial compositional turnover of fungal communities in an alpine ridge-to-snowbed gradient

The main gradient in vascular plant, bryophyte and lichen species
composition in alpine areas, structured by the topographic gradient from
wind-exposed ridges to snowbeds, has been extensively studied. Tolerance
to environmental stress, resulting from wind abrasion and desiccation
towards windswept ridges or reduced growing season due to prolonged snow
cover towards snowbeds, is an important ecological mechanism in this
gradient. The extent to which belowground fungal communities are
structured by the same topographic gradient, and the eventual mechanisms
involved, are less well known. In this study, we analyzed variation in
fungal diversity and community composition associated with roots of the
ectomycorrhizal plant Bistorta vivipara along the ridge-to-snowbed
gradient. We collected root samples from fifty B. vivipara plants in ten
plots in an alpine area in central Norway. The fungal communities were
analyzed using 454 pyrosequencing analyses of tag encoded ITS1 amplicons.
A distinct gradient in the fungal community composition was found that
coincided with variation from ridge to snowbeds. This gradient was
paralleled by change in soil content of carbon, nitrogen and phosphorus. A
large proportion (66%) of the detected 801 non-singleton operational
taxonomic units (OTUs) were ascomycetes, while basidiomycetes dominated
quantitatively (i.e., with respect to number of reads). Numerous fungal
OTUs, many with taxonomic affinity to Sebacinales, Cortinarius and
Meliniomyces, showed distinct affinities either to ridge or to snowbed
plots, indicating habitat specialization. The compositional turnover of
fungal communities along the gradient was not paralleled by a gradient in
species richness.