Terrain and landform influence on Tsuga canadensis (L.) Carriere (Eastern Hemlock) distribution in the southern Appalachian Mountains

  • Authors: Narayanaraj, G.; Bolstad, P.V.; Elliott, K.J.; Vose, J.M.
  • Publication Year: 2010
  • Publication Series: Scientific Journal (JRNL)
  • Source: CASTANEA 75(1): 1–18

Abstract

We examined the relationships between hemlock distribution and abundance and terrain attributes for the Coweeta Basin in the southern Appalachian Mountains. Field measurements were combined with GIS mapping methods to develop predictive models of abundance and distribution of Tsuga canadensis (L.) Carriere (eastern hemlock) and evaluate the co-occurrence of Rhododendron maximum L. (rosebay) and Kalmia latifolia L. (mountain laurel). Terrain variables were derived from USGS DEM 30-meter digital maps. Elevation, slope, aspect, terrain shape index, landform, and distance from stream were calculated from field measurements and the digital data. Terrain attributes such as elevation (r² = 0.97, p < 0.0001), distance to stream (r² = 0.94, p < 0.0001), and terrain shape index (r² = 0.61, p = 0.0015) were good predictors of T. canadensis abundance. Terrain shape index explained 56% of the variation in R. maximum percent aerial cover (r² = 0.56, p = 0.005). In the Coweeta Basin, T. canadensis was distributed as few, large trees mostly concentrated in near-stream locations, and it was closely associated with R. maximum. Tsuga canadensis mortality due to Adelges tsugae Annand (hemlock wooly adelgid) will result in a minor decrease in basin-wide basal area, but will substantially reduce near-stream basal area, and will also remove the largest trees in near-stream environments. In similar landscapes across the southern Appalachians, where T. canadensis co-occurs with R. maximum, riparian shading will likely remain unchanged.

  • Citation: G. Narayanaraj; P.V. Bolstad; K.J. Elliott; J.M. Vose 2010. Terrain and landform influence on Tsuga canadensis (L.) Carriere (Eastern Hemlock) distribution in the southern Appalachian Mountains. CASTANEA 75(1): 1–18.
  • Posted Date: May 17, 2010
  • Modified Date: July 16, 2010
  • Requesting Print Publications

    Publication requests are subject to availability. Fiscal responsibility limits the hardcopies of publications we produce and distribute. Electronic versions of publications may be downloaded, distributed and printed.

    Please make any requests at pubrequest@fs.fed.us.

    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.