The Influence of Soil-Site Factors on Productivity of Even-Aged Red Maple Stands in Michigan and Wisconsin
Haag, Carl L.
University of Wisconsin-Stevens Point, College of Natural Resources
MetadataShow full item record
Sixty even-aged red maple (Acer rubrum L.) stands were sampled throughout northern Wisconsin and Michigan. The relationship of physical and chemical parameters to site productivity, as measured by site index and total above-ground biomass, was determined through forward stepwise multiple regression. In general, equations developed using soil physical factors only yielded the most precise estimates when applied to an independent data set, in addition to being the most easily applied in a field situation. Physical factors included in prediction equations were related to water table depth, presence of a zone of clay increase in the subsoil, and overall soil profile development, particularly the spodic horizon. Equations using chemical factors were included as well. Through the use of cluster analysis, three productivity groups were developed based on land type and soil drainage. In general, differences in productivity estimates between groups were significant. The most productive soils (productivity group I) were those with a sandy surface texture underlain by a horizon with an increase in clay content and a moderately well- to a somewhat poorly drained soil profile. The least productive soils (productivity group III) were well- to excessively drained, had a coarse sandy texture throughout, a poorly developed soil profile, and little or no Bh or Bhs horizon. The largest forest floor nutrient pool was associated with the group I soils. However, soil nutrient pools displayed greater variability, with group I soils having the greatest amount of N and K, group II soils having the greatest amounts of Ca and Mg, and group III soils having the most P.