Quantifying wind damage associated with variable retention harvesting in coastal British Columbia

•Wind damage to retention in forest cutblocks varies regionally in coastal BC.•Small retention patches are more vulnerable to windthrow than large patches.•Topographic position and orientation of stand edges to storm wind affect windthrow.•Stand height, species and fetch distance across openings affect wind damage levels.•Wind damage to trees in small (0.22 ha) retention patches ranged from 23–53%.