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Variability of Cenococcum colonization and its ecophysiological significance for young conifers at alpine–treeline
Author(s) -
Hasselquist Niles,
Germino Matthew J,
McGonigle Terence,
Smith William K
Publication year - 2005
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/j.1469-8137.2005.01275.x
Subject(s) - colonization , pinus <genus> , biology , alpine plant , ecology , botany
Summary• Plants establishing in environments that are marginal for growth could be particularly sensitive to mycorrhizal associations. We investigated ectomycorrhizal colonization and its significance for young conifers growing at, or above, their normal limits for growth, in the alpine–treeline ecotone. • Colonization of seedlings (< 1 yr old) and juveniles (2‐ to 10‐yr‐old) of Picea engelmannii and Abies lasiocarpa by Cenococcum geophilum was determined in a field study, and effects of Cenococcum on Picea seedling ecophysiology were investigated in a glasshouse. • Colonization by Cenococcum was c . 20‐fold greater for juveniles than seedlings, and ~4‐fold greater adjacent compared with ~7 m away from trees. Juveniles of Picea were more colonized at timberline than Abies , and the opposite relationship was observed in forest. Colonization enhanced seedling water potential, but not phosphorus concentrations or photosynthesis. • These landscape and age‐dependent variations in colonization correspond well with known variations in conifer physiology and establishment near timberline. Facilitation of seedling establishment by older trees at alpine–treeline may include a below‐ground, mycorrhizal component that complements previously reported effects of trees on the microclimate and ecophysiology of seedlings.