Cytopathological and external observations on red spruce (Picea rubens Sarg.) needles damaged in winter in Vermont

The red spruce ( sarg.) population in the Green Mountains in Vermont has showed foliar deterioration that has not been fully explained. The most characteristic needle injuries of the sensitive trees appear in late winter when the first-year needles turn brown. The cytopathological and external observations on the symptoms support the interpretation that winter stress triggers the damage. It is possible that some anthropogenic stress factors (components of acid deposition or ozone) and/or natural factors predispose the trees to the damage.Picea rubens