Multiplicity of Fungal Form and Function in Arctic-Alpine Ecosystems
Cripps, Cathy L , Horak, Egon .
Global view of ectomycorrhizal fungi on Salix in Arctic-alpine habitats: Implications for a shift in microbe function with predicted shrub expansion.
The Arctic-alpine biome makes up 8% of the earth’s land yet in most areas ten species of higher plants comprise over 90% of the biomass. In the northern hemisphere this includes primarily sedges and woody plants such as Salix, Betula and Dryas which host ectomycorrhizal (ECM) fungi. The diversity of ECM fungi that associate with woody plants in Arctic-alpine habitats is limited and includes primarily Agaricales with a circumpolar distribution. Therefore, a significant portion of the earth’s primary productivity depends on a limited set of mutualistic fungi that survive in harsh AA habitats and benefit a few host plants. Diverse ECM genera for Arctic-alpine Salix spp. are: Amanita, Cortinarius, Entoloma, Hebeloma, Inocybe, Laccaria, Lactarius and Russula. Below-ground studies add less diverse but possibly more abundant Cenococcum, Sebacina, Tomentella species and ascomycetes. A priori knowledge of ECM fungi is necessary to identify key species and delineate individual roles in tundra habitats. A survey of ECM with Salix in the Rocky Mountain alpine identified 70 species in comparison to Svalbard high Arctic 72, Arctic Greenland 150 and the alpine Alps 199; many are common to all areas. Diversity in ECM functioning is less well known; some alpine Hebelomas degrade complex polymers and other ECM fungi access inorganic P via phosphatases. Tundra habitats are a mosaic of vegetation types with compositionally and functionally distinct microbial communities supported by different mycorrhizal types e.g. arbuscular with grasses and forbs, ericoid with ericaceous plants, arbutoid with woody ericaceous shrubs and ECM with Salix, Betula and Dryas mats. Current studies suggest shrubs are expanding in the arctic tundra; inherent in this change are shifts in relative abundances of mycorrhizal types. The potential for an increase in ECM fungi has implications for a fundamental shift in microbe functioning on a large scale in AA habitats.
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1 - Montana State University, Plant Sciences and Plant Pathology Dept, 119 Plant Biosciences Building, Bozeman, MT, 59717-3150, USA
2 - Nikodemweg 5, Innsbruck, AT-6020, Austria
Presentation Type: Symposium or Colloquium Presentation
Location: Ballroom 3/Cliff Lodge - Level B
Date: Tuesday, July 28th, 2009
Time: 8:15 AM