About Us | Help Videos | Contact Us | Subscriptions



This article in JEQ

  1. Vol. 31 No. 5, p. 1623-1629
    Received: Dec 13, 2001

    * Corresponding author(s): bockheim@facstaff.wisc.edu
Request Permissions


Ion Cycling in Hemlock–Northern Hardwood Forests of the Southern Lake Superior Region

  1. J. G. Bockheim * and
  2. S. E. Crowley
  1. Department of Soil Science, Univ. of Wisconsin, 1525 Observatory Dr., Madison, WI 53706-1299


Upland forests of the southern Lake Superior region are diverse and contain a shifting mosaic of eastern hemlock [Tsuga canadensis (L.) Carr.] and northern hardwood forests dominated by sugar maple (Acer saccharum Marsh.). In this study, we survey the relative effects of management practice (old growth vs. managed), forest cover type (hemlock vs. northern hardwood), and soil great group (Entic Haplorthod vs. Alfic Oxyaquic Fragiorthod) on ion cycling as a precursor to a longer-term, more detailed study. Bulk precipitation, throughfall, and soil leachates at three depths were collected for two growing seasons in eight stands on the Ottawa National Forest in the Upper Peninsula of Michigan. A total of 1210 solutions were analyzed for pH, Na, K, Mg, Ca, Cl, NO3, and SO4 Losses of base cations (Ca, Mg, K) and SO4 from the bottom of the rooting zone generally were greater in old-growth than in managed northern hardwoods on both fragic and nonfragic soils. Leaching losses of base cations and NO3 usually were greater beneath old-growth northern hardwoods than beneath old-growth hemlock on both soil types and for both forest cover types and management practices on fragic than nonfragic soils. Management practice, forest cover type, and soil type all appear to affect ion cycling within these forests. All of the stands featured striking losses of base cations that probably are influenced strongly by NO3 and SO4 in atmospheric deposition.

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

Copyright © 2002. American Society of Agronomy, Crop Science Society of America, Soil Science SocietyPublished in J. Environ. Qual.31:1623–1629.