title: Long-term increase in snow depth leads to compositional changes in arctic ectomycorrhizal fungal communities.
abstract: Many arctic ecological processes are regulated by soil temperature that is tightly interconnected with snow cover distribution and persistence. Recently, various climate-induced changes have been observed in arctic tundra ecosystems, e.g. shrub expansion, resulting in reduction in albedo and greater C fixation in aboveground vegetation as well as increased rates of soil C mobilization by microbes. Importantly, the net effects of these shifts are unknown, in part because our understanding of belowground processes is limited. Here, we focus on the effects of increased snow depth, and as a consequence, increased winter soil temperature on ectomycorrhizal (ECM) fungal communities in dry and moist tundra. We analyzed deep DNA sequence data from soil samples taken at a long-term snow fence experiment in Northern Alaska. Our results indicate that, in contrast with previously observed responses of plants to increased snow depth at the same experimental site, the ECM fungal community of the dry tundra was more affected by deeper snow than the moist tundra community. In the dry tundra, both community richness and composition were significantly altered while in the moist tundra, only community composition changed significantly while richness did not. We observed a decrease in richness of Tomentella, Inocybe and other taxa adapted to scavenge the soil for labile N forms. On the other hand, richness of Cortinarius, and species with the ability to scavenge the soil for recalcitrant N forms, did not change. We further link ECM fungal traits with C soil pools. If future warmer atmospheric conditions lead to greater winter snow fall, changes in the ECM fungal community will likely influence C emissions and C fixation through altering N plant availability, fungal biomass and soil-plant C-N dynamics, ultimately determining important future interactions between the tundra biosphere and atmosphere.
authors.affiliation: Naturalis Biodiversity Center, P.O. Box 9517, 2300 RA, Leiden, The Netherlands.|Section for Genetics and Evolutionary Biology (Evogene), Department of Biosciences, University of Oslo, P.O. Box 1066 Blindern, NO-0316, Oslo, Norway.
authors.forename: Luis N
authors.initials: LN
authors.lastname: Morgado
authors.affiliation: Naturalis Biodiversity Center, P.O. Box 9517, 2300 RA, Leiden, The Netherlands.|Faculty of Science, Leiden University, P.O. Box 9502, 2300 RA, Leiden, The Netherlands.
authors.forename: Tatiana A
authors.initials: TA
authors.lastname: Semenova
authors.affiliation: Department of Biological Sciences, University of Alaska Anchorage, Anchorage, AK, USA.
authors.forename: Jeffrey M
authors.initials: JM
authors.lastname: Welker
authors.affiliation: HOMER Energy, 1790 30th St, Suite 100, Boulder, CO, 80301, USA.
authors.forename: Marilyn D
authors.initials: MD
authors.lastname: Walker
authors.affiliation: Naturalis Biodiversity Center, P.O. Box 9517, 2300 RA, Leiden, The Netherlands.|Faculty of Science, Leiden University, P.O. Box 9502, 2300 RA, Leiden, The Netherlands.|Plant Conservation and Population Biology, KU Leuven, Kasteelpark Arenberg 31, Box 2437, 3001, Leuven, Belgium.
authors.forename: Erik
authors.initials: E
authors.lastname: Smets
authors.affiliation: Naturalis Biodiversity Center, P.O. Box 9517, 2300 RA, Leiden, The Netherlands.|Faculty of Science, Leiden University, P.O. Box 9502, 2300 RA, Leiden, The Netherlands.
authors.forename: József
authors.initials: J
authors.lastname: Geml
mesh_terms: D000413:Alaska; D001110:Arctic Regions; D038821:Mycorrhizae; D012914:Snow; D012987:Soil; D065929:Tundra
chemical_list: D012987:Soil
keywords: ITEX; Toolik Lake; arctic ecology; climate changes; fungal ecology; snow fence; snow pack