Variability of Cenococcum colonization and its ecophysiological significance for young conifers at alpine-treeline

Abstract

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 similar to 4-fold greater adjacent compared with similar to 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.

Keywords

Abies lasiocarpa; alpine-treeline ecotone; Cenococcum geophilum; conifer seedlings; ecophysiology; ectomycorrhizas; Picea engelmannii

Published in

New Phytologist
2005, Volume: 165, number: 3, pages: 867-873

UKÄ Subject classification

Forest Science


Publication identifier

DOI: https://doi.org/10.1111/j.1469-8137.2005.01275.x

Permanent link to this page (URI)

https://res.slu.se/id/publ/99439