Scar closure and future timber value losses from thinning damage in western Oregon

This study investigated bark growth and decay development after thinning damage at 2 western Oregon sites, and estimated value loss with a tree growth model. All scars that remained open in western hemlock and Sitka spruce had advanced decay 13 years after initial wounding. Scars less than four inches wide closed in eight years. Douglas-fir was more resistant to decay; no rot was observed in scars less than 21 years old. Advanced decay and pitch rings, however, were observed in 29-year-old scars, both open and closed. Because of these defects, future value loss increased with time after wounding and with higher stand damage levels.