Winter damage to foliage as a factor in red spruce decline

Observations made over the past 5 years suggest that the most recent needles of red spruce (Picearubens Sarg.) in the Green Mountains of Vermont, U.S.A., are prone to browning and loss owing to cold stress and (or) winter desiccation. Particularly severe events occurred in the winters of 1981 and 1984 and the latter event was observed in detail. On many trees in all size classes, a large proportion of the 1983 needles turned reddish-brown between late February and early April, 1984. This pattern of discoloration and subsequent defoliation, which appears to be repeated periodically, can account for the visual symptoms of declining red spruce in the montane forests of the northeastern United States. A predisposition to winter damage appears to be a component of the decline and could result from natural or possibly anthropogenic factors.