Windthrow Monitoring of Alternative Silvicultural Systems in Montane Coastal Forests

This research documents a six-year monitoring study at the Montane Alternative Silvicultural Systems site, examining how different harvesting methods influence the likelihood of windthrow damage in coastal montane forests. The study quantified stem loss across four treatments, including clearcut, shelterwood, green tree retention, and patch cut, finding that windthrow losses were substantial across the site, which was not initially considered high risk. Although low-density green tree retention experienced the highest proportion of damaged trees, the overall greatest number of wind-damaged stems occurred in the shelterwood treatment. The data indicates that small, concentrated patch cuts resulted in the lowest amount of windthrow, suggesting that grouped retention is a more effective strategy than dispersed retention for minimizing wind damage. The authors conclude that adopting group retention strategies can better conserve structural forest elements while addressing challenges related to windthrow risk.