title: Seasonal trends in the biomass and structure of bryophyte-associated fungal communities explored by 454 pyrosequencing.
abstract: Bryophytes are a dominant vegetation component of the boreal forest, but little is known about their associated fungal communities, including seasonal variation within them. Seasonal variation in the fungal biomass and composition of fungal communities associated with three widespread boreal bryophytes was investigated using HPLC assays of ergosterol and amplicon pyrosequencing of the internal transcribed spacer 2 (ITS2) region of rDNA. The bryophyte phyllosphere community was dominated by Ascomycota. Fungal biomass did not decline appreciably in winter (P=0.272). Significant host-specific patterns in seasonal variation of biomass were detected (P=0.003). Although seasonal effects were not the primary factors structuring community composition, collection date significantly explained (P=0.001) variation not attributed to locality, host, and tissue. Community homogenization and a reduction in turnover occurred with the onset of frost events and subzero air and soil temperatures. Fluctuations in the relative abundance of particular fungal groups seem to reflect the nature of their association with mosses, although conclusions are drawn with caution because of potential methodological bias. The moss-associated fungal community is dynamic, exhibiting seasonal turnover in composition and relative abundance of different fungal groups, and significant fungal biomass is present year-round, suggesting a winter-active fungal community.
authors: Department of Ecology and Natural Resource Management, Norwegian University of Life Sciences, PO Box 5003, NO-1432 Ås, Norway.|Microbial Evolution Research Group (MERG), Department of Biology, University of Oslo, PO Box 1066 Blindern, NO-0316 Oslo, Norway.
authors: Marie L
authors: ML
authors: Davey
authors: Norwegian Forest and Landscape Institute, Fanaflaten 4, NO-5244 Fana, Norway.
authors: Einar
authors: E
authors: Heegaard
authors: Department of Botany, Natural History Museum, University of Oslo, PO Box 1172 Blindern, NO-0318 Oslo, Norway.
authors: Rune
authors: R
authors: Halvorsen
authors: Department of Ecology and Natural Resource Management, Norwegian University of Life Sciences, PO Box 5003, NO-1432 Ås, Norway.
authors: Mikael
authors: M
authors: Ohlson
authors: Microbial Evolution Research Group (MERG), Department of Biology, University of Oslo, PO Box 1066 Blindern, NO-0316 Oslo, Norway.
authors: Håvard
authors: H
authors: Kauserud
mesh_terms: D018533:Biomass; D044002:Bryophyta / Q000382:microbiology*; D004875:Ergosterol / Q000378:metabolism; D005658:Fungi / Q000145:classification / Q000235:genetics* / Q000254:growth & development*; D014644:Genetic Variation; D016014:Linear Models; D009664:Norway; D010788:Photosynthesis; D012621:Seasons; D017422:Sequence Analysis, DNA
chemical_list: D004875:Ergosterol