Overview

• After heavy rain returned surface moisture to normal on Vancouver Island, experts say underlying drought damage still threatens tree stability.
• A mother and her five-month-old son were killed by a falling tree on July 31 at Cumberland Lake Park, and a woman was badly injured by a falling limb on Aug. 10 at Pipers Lagoon in Nanaimo.
• Researchers report large branches dropping on calm days, citing observations on the University of Victoria campus and a Douglas fir shedding limbs on Burnaby Mountain.
• Scientists link the failures to prolonged dryness that depletes sugars and defenses, followed by insect and fungal rot that causes internal decay.
• Western red cedar and maples are especially vulnerable, urban trees face added stress from sun and compacted soils, and even arborists cannot always predict failures despite visible warning signs.