Skip to Main Content
U.S. Forest Service
Caring for the land and serving people

United States Department of Agriculture

Home > Search > Publication Information

  1. Share via EmailShare on FacebookShare on LinkedInShare on Twitter
    Dislike this pubLike this pub
    Author(s): John F. Walker; Orson K. Miller; Tom Lei; Shawn Semones; Erik Nilsen; B.D. Clinton
    Date: 1999
    Source: Mycorrhiza (1999) 9:49-56
    Publication Series: Miscellaneous Publication
    PDF: View PDF  (458 KB)

    Description

    Thickets of Rhododendron maximum (Ericaceae) (Rm) is the southern Appalachians severely limit regeneration of hardwood and coniferous seedlings. Experimental blocks were established in and out of Rm thickets in a mature, mixed hardwood/conifer forest in Macon County, N.C. Litter and organic layer substrates were removed, cornposited and redistributed among plots within the blocks (except for control plots). Seedliugs of northern red oak (Quercus rubra) and eastern hemlock (Tsuga canadensis) were planted in the plots and harvested at the end of the first and second growing seasous. Litter manipulation had no effect on total mycorrhizal colonization, but the distribution of Cenococcum geophilum mycorrhizae was altered. After the first year, percent mycorrh.izal colonization of hemlocks not in Rm thickets (62%) was at least three times higher than in Rm thickets (19%), and the ramification index (no. of mycorrhizae cm-1) had increased by more than a factor of four (2.83 versus 0.61). In addition, colonization of l-year-old hemlocks by C. geophilum was significautly higher within blocks with (10.4%) than without (4.6%) Rm. Differences in mycorrhizal colonization, ramification indices and colonization by C. geophilum were absent or less pronounced on 2-year-old hemlocks and 1 and 2-year-old oak seedlings. The biomasses of first year oak roots and shoots and second year shoots were 50% less in Rm thickets. Biomasses of first year hemlock roots and second year shoots were, also reduced Mycorrhizal parameters were correlated with some growth parameters only for hemlock seedlings, but did not explain most of the variation observed.

    Publication Notes

    • You may send email to pubrequest@fs.fed.us to request a hard copy of this publication.
    • (Please specify exactly which publication you are requesting and your mailing address.)
    • We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
    • This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.

    Citation

    Walker, John F.; Miller, Orson K., Jr.; Lei, Tom; Semones, Shawn; Nilsen, Erik; Clinton, B.D. 1999. Suppression of ectomycorrhizae on canopy tree seedlings in Rhododendron maximum (Eriqceae) thickets in the southern Appalachians. Mycorrhiza (1999) 9:49-56

    Keywords

    Eastern Hemlock, Ectomycorrhiza, Mycorrhizal-colonization, Northern red oak, Cenococcum geophilum

    Related Search


    XML: View XML
Show More
Show Fewer
Jump to Top of Page
https://www.fs.usda.gov/treesearch/pubs/4728