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

Abstract

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.

Predicting species distribution and abundance responses to climate change: why it is essential to include biotic interactions across trophic levels

“…However, these responses may depend on how warming affects plant species identities (Heinemeyer & Fitter 2004). Therefore, responses of the mycorrhizal community to climate warming (and drought) are probably influenced mostly through changes in plant community composition (Staddon et al 2003) and less through direct effects of warming on the soil organisms (Fujimura et al 2008). These effects of warming on nutrient-cycling and mycorrhizal associations may influence plant nutritional status, which can influence aboveground plantinsect -enemy interactions, depending on the feeding mode and diet breadth of the insects, as well as on the identity of the mycorrhizal fungal species involved (Koricheva et al 2009).…”

“…These responses will be mostly due to enhanced plant productivity. Soil warming may affect mycorrhizal effectiveness positively (Rillig et al 2002), whereas it does not necessarily change mycorrhizal community composition (Fujimura et al 2008). In general, it is assumed that plant-mycorrhizal fungi interactions benefit from climate warming, especially in Arctic regions (Kytoviita & Ruotsalainen 2007).…”

Rhizomes and Roots of Rare Arctic-Alpine Snowfield Plants on the Edges of Retreating Snowfields at Glacier National Park, Montana

“…On the risers, Salix arctica, the arctic willow, and Dryas octopetala, of the rose family (Rosaceae), are co-dominant low-growing ectomycorrhizal shrubs that form extensive mats [5,6]. Experimental warming of the rhizosphere fungi of S. arctica suggested that fungal community biomass increased with increased belowground allocation of carbon [7]. Alpine ectomycorrhizal symbioses and belowground carbon pools may therefore be influenced by the warmer temperatures associated with climate change.…”

Fungal community assessment in Canadian arctic soils from Alexandra Fiord, Ellesmere Island, Nunavut.

“…Ca reacts with P, to create calcium phosphate which only a few fungi can solubilize (Fujimura et al 2008;Golubic and Schneider 1979] and excess carbonate increases the pH. Therefore, fungi that can solubilize calcium phosphate at high pH would have a competitive advantage over fungi that cannot.…”

“…Another study by Fujimura et al (2008), who studied the effect of warming on the root associated fungal community in Alexandra Fiord documented that site and soil physicochemical gradients are the most important factors determining fungal community structure. This result was consistent with our study observations, where the number of different genotypes, richness, and evenness between the sites were different according to site and soil physicochemical gradients.…”