Carbon limitation leads to suppression of first year oak seedlings beneath evergreen understory shrubs in Southern Appalachian hardwood forests

  • Authors: Beier, Colin M.; Horton, Jonathan L.; Walker, John F.; Clinton, Barton D.; Nilsen, Erik T.
  • Publication Year: 2005
  • Publication Series: Miscellaneous Publication
  • Source: Plant Ecology. 176: 131-142

Abstract

Inhibition of canopy tree recruitment beneath thickets of the evergreen shrubs Rhododendron maximum L. and Kalmia latifolia L. has long been observed in South Appalachian forests, yet the mechanisms of this process remain unresolved. We present a first-year account of suppression of oak seedlings in relation to Rhododendron and Kalmia basal area, light and resource availability, seedling performance and the rates of seedling damage (i.e., herbivory). We found no evidence of first-year seedling suppression or significant resource deficiencies beneath thickets of K. latifolia in mature mixed hardwood stands. Suppression beneath R. Maximum was apparent during the first growing season. We found that seedling biomass, light availability prior to canopy closure, and seedling tissue C.:N ratios were negatively correlated with R. maximum basal area. Basal area of R. maximum was positively correlated with seedling mortality rates, soil [A1], and early-growing season leaf herbifory rates. Seedling growth was positively correlated with light and tissue C:N, while negatively correlated with soil [A1]. Overall, our results support the inhibition model of shade-mediated carbon limitation beneath dense understory shrubs and indicate the potential importance of herbivory and aluminum toxicity as components of a suppression mechanism beneath R. maximum thickets. We present a casual model of first year inhibition beneath R. maximum in the context of our findings and the results of prior studies.

  • Citation: Beier, Colin M.; Horton, Jonathan L.; Walker, John F.; Clinton, Barton D.; Nilsen, Erik T. 2005. Carbon limitation leads to suppression of first year oak seedlings beneath evergreen understory shrubs in Southern Appalachian hardwood forests. Plant Ecology. 176: 131-142
  • Keywords: Deep shade, herbivory, inhibition, Quercus, Kalmia, Rhododendron
  • Posted Date: April 1, 1980
  • Modified Date: August 22, 2006
  • Print Publications Are No Longer Available

    In an ongoing effort to be fiscally responsible, the Southern Research Station (SRS) will no longer produce and distribute hard copies of our publications. Many SRS publications are available at cost via the Government Printing Office (GPO). Electronic versions of publications may be downloaded, printed, and distributed.

    Publication Notes

    • This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
    • Our online publications are scanned and captured using Adobe Acrobat. During the capture process some typographical errors may occur. Please contact the SRS webmaster if you notice any errors which make this publication unusable.
    • To view this article, download the latest version of Adobe Acrobat Reader.