The effect of timber harvest and wildfire on soil physical and nutritional dynamics in two boreal forest ecosite types in eastern Manitoba.

摘要

Forest ecosystems undergo both natural and human induced disturbances. Depending on disturbance type, soil physical and chemical parameters show different response patterns during the recovery phase. An added level of complication is the ecological site types occurring throughout a forested area. The identification of indicators of soil fertility and the successful emulation of a natural disturbance regime were the scope of this research.; The research presented herein took place in the Manitoba Model Forest (MBMF), located in eastern Manitoba, where the natural disturbance regime is wildfire. Timber harvest strategies used in the area are designed to emulate a wildfire (5% retention of standing timber and extensive slash inputs) and clearcut harvesting. The objective of this study was to document changes in forest floor and soil properties prior to and following harvesting, and to compare these properties to those found in a small wildfire that burned in the MBMF in late summer 1998, which serves as a benchmark to the harvest. In the two study areas, both thin mineral soil (5--20 cm) and moderately deep mineral soil (20--100 cm) ecosite types were monitored at four dates over a two year period for soil physical and nutritional response patterns. (Abstract shortened by UMI.)