HARVESTING IMPACTS ON QUAKING ASPEN REGENERATION IN NORTHERN MINNESOTA

The increasing commercial demand for quaking aspen (Populus tremuloides Michx.) has sparked renewed interest in aspen silvics and management. While aspen generally regenerates vigorously by root suckering following clear-cutting, recent reports of unsuccessful regeneration suggest a linkage to harvesting activities. Accordingly we evaluated the effects of harvest season and equipment trafficking on aspen regeneration in a glaciolacustrine landform in northern Minnesota. Regeneration vigor, as measured by stem density, stem height, and crown closure was greater in winter-harvested areas. Increased equipment trafficking significantly reduced regeneration in stands harvested during the summer. We detected no significant increases in soil density associated with equipment trafficking; however, reduced regeneration was correlated with increased amounts of rutting and soil scarification. For a given level of trafficking, aspen regeneration increased along the annual chronosequence of harvesting later and later in the summer.