Nitrogen Mineralization Patterns of Boreal Forest Soils
Offord, J. L.. 1999. M.Sc. Thesis. Dept. Renewable Resources, University of Alberta, Edmonton, AB
Abstract
Soil temperatures and moistures were monitored in two Alberta field sites from May,
1997 to September 1998. Nitrogen 0.I) mineralization rates were measured using ion
exchange membranes in the field from June 1997 to May 1998. In association with this
monitoring intact organic horizon cores (LFH) and homogenized Ae cores from Alberta
and Quebec were incubated under various conditions between 23 1 and 3 13 days. Every
14 - 28 days, each core was leached with 0.01 M CaCl for mineral N determination. To
accommodate variability in soil N content and site history, results were normalized to a
soil N basis. Results indicate net N mineralization is horizon specific not site specific;
net N mineralization over long times was weakly related to lower soil temperatures; and
differences in moisture tension did not create differences in specific net N mineralization.
A protocol is proposed to estimate N mineralization from soils across Canada for use by
present and future forest managers.
