Ectomycorrhizal (EM) assemblages associated with Alnus spp. are often distinct in composition and richness from other host plants. To examine the EM assemblage associated with A. rubra, a common tree in western coastal North America, we sampled four A. rubra forests varying in age, management history, and geographic location in Oregon, USA. From the 364 EM root tip rDNA ITS sequences, we found a total of 14 EM taxa. The five most abundant taxa, Tomentella sp. 3, Alnicola escharoides, Tomentella sp. 1, Lactarius cf. obscuratus, and Alpova diplophloeus, represented 80. % of the samples and were present at all four sites. Assemblage structure differed significantly among young managed sites and older unmanaged sites but not by geographic location. The younger managed sites had higher tree density, Frankia frequency, and soil nitrogen than older unmanaged sites. Phylogenetic analyses revealed that Alnus-associated EM congeners were not closely related, indicating the distinct nature of Alnus EM assemblages is not due to a unique co-evolutionary history.
|Original language||English (US)|
|Number of pages||10|
|State||Published - Aug 2010|
Bibliographical noteFunding Information:
The authors thank Andrew Bluhm and David Hibbs for assistance with use of the HSC study sites, J. Yahya for assistance with the Frankia frequency analysis, Joe Ammirati, Greta Binford, Ursula Eberhardt, Brandon Matheny, Martin Ryberg, Andy Taylor, and Else Vellinga for assistance with the phylogenetic analyses. Many members of the Lewis and Clark College Biology department, Martha Palomino, Kabir Peay, Marjorie Weber, and two reviewers provided constructive comments on a previous version of this manuscript. Funding was provided by the Murdock Charitable Trust, the Lewis & Clark College Student Academic Affairs Board, and the National Science Foundation (DEB 0742868 to P. Kennedy and T. Bruns).
- Alnus rubra
- Assemblage structure
- Host specificity
- Pacific Northwest