The effect of experimental warming on the root-associated fungal community of Salix arctica.

The effect of experimental warming on the root-associated fungal community of arctic willow (Salix arctica) was studied in three distinct habitats at a tundra site in the Canadian High Arctic. Plots were passively warmed for 5-7 years using open-top chambers and compared to control plots at ambient temperature. Fungal communities were assessed using terminal restriction fragment length polymorphisms. We found the following: (1) the root-associated fungal community in these high arctic tundra habitats is highly diverse; (2) site and soil characteristics are the most important drivers of community structure and (3) warming increased the density of different genotypes on individual root sections but has not (yet) affected the composition, richness or evenness of the community. The change in genotype density in the warmed plots was associated with an increase in PCR amplification efficiency, suggesting that increased C allocation belowground is increasing the overall biomass of the fungal community.