About Us | Help Videos | Contact Us | Subscriptions
 

Abstract

 

This article in SSSAJ

  1. Vol. 55 No. 6, p. 1782-1791
     
    Received: Nov 12, 1990
    Published: Nov, 1991


    * Corresponding author(s):
 View
 Download
 Alerts
 Permissions
 Share

doi:10.2136/sssaj1991.03615995005500060046x

High-Elevation Forest Soils of the Southern Appalachians: II. Geomorphology, Pedogenesis, and Clay Mineralogy

  1. S. B. Feldman ,
  2. L. W. Zelazny and
  3. J. C. Baker
  1. Dep. of Crop and Soil Environmental Sciences, Virginia Polytechnic Inst. and State Univ., Blacksburg, VA 24061

Abstract

Abstract

We investigated soil mineral weathering sequences in three geologically distinct high-elevation areas of southern Appalachian spruce-fir (Picea rubens Sarg.-Abies fraseri [Pursh.] Poir) forests in order to elucidate the pedogenic factors that distinguish these unique soils from their low-elevation counterparts. Four pedons representing a developmental sequence ranging from soils having distinct spodic field morphology (E plus Bhs horizons) to those having either minimal (weak E horizons) or no spodic character (umbric epipedons/cambic horizons) were selected for further study from a total of 35 excavated pits. Whereas the mineralogy of sand and silt fractions reflected inheritance from parent materials, clay mineral suites of all soils were very similar, indicating biotic and climatic controls on weathering. Surface-horizon clay fractions were dominated by regularly interstratified mica/vermiculite and high-charge smectite, which decreased with depth in all profiles. Subsoil clay fractions were principally composed of gibbsite and hydroxy-interlayered vermiculite. Genesis of secondary 2:1 layer silicates in these soils occurs initially by the pseudomorphic transformation of biotite to both hydrobiotite and vermiculite. However, direct conversion of biotite to kaolinite is of little importance in these soils. The demonstrated mobility of Al-organic complexes out of surface horizons and the inability of hydroxy-Al interlayers to form in vermiculite in the presence of organic acids suggest that these soils are undergoing early stages of podzolization and that they are more similar to northern Appalachian Spodosols than they are to adjacent low-elevation soils of the southern mountains.

  Please view the pdf by using the Full Text (PDF) link under 'View' to the left.

Copyright © . Soil Science Society of America