2002 ARCSS All-Hands Workshop

Ectomycorrhizal diversity of White Spruce (Picea glauca) at three treeline sites along a latitudinal gradient in Alaska

Kendra Calhoun¹, Jennifer Lansing², Roger Ruess^3
1Department of Biology and Wildlife, University of Alaska Fairbanks, 211 Irving I, North Koyukuk Drive, Fairbanks, AK, 99775, USA, Phone (907) 474-1983, Fax (907) 474-7906, ftklc1@uaf.edu
²Center for Conservation Biology, University of California, Riverside, CA, USA
³Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK, USA

Factors limiting white spruce (Picea glauca) growth at treeline are poorly understood but are central in predicting future forest/tundra boundaries in response to global warming. Nutrient limitation and tissue loss are thought to reduce growth and reproductive success at treeline. Soil microbial communities may also have an effect on the establishment and success of trees growing at treeline. Mycorrhizae, the mutualistic symbioses between plants and fungi, are an essential component of ecosystem structure and function. However, research regarding the diversity and species composition of ectomycorrhizae at high latitudes or at treeline is very limited. Our goal is to determine ECM diversity and species composition at treeline and contiguous intact forest. Ectomycorrhizae were sampled at three sites within each of three geographically distinct mountain ranges within Alaska from both forest and treeline sites. Soil cores were sampled from ten randomly selected trees at each location and site throughout the summer of 2001. White spruce roots were sorted from cores and ECMs were morphotyped and quantified for percent infection. Forty-seven morphotypes where found in the Chugach, forty in the White Mountains and fifteen in the Brooks Range. Overall, there was no difference in the number of morphotypes found between forest and treeline sites.

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