PROCEEDINGS: Index of Abstracts

EFFECTS OF CALCIUM FERTILIZATION AND ACID MIST ON CALCIUM CONCENTRATION AND COLD TOLERANCE OF RED SPRUCE NEEDLES

G. R. Strimbeck-1, David R. Vann-2, and Arthur H. Johnson-2

1-University of Vermont, School of Natural Resources, Burlington, VT 05405. 2-University of Pennsylvania, Department of Geology, Philadelphia, PA 19104.

Several studies have shown that exposure to acid mist impairs cold tolerance of red spruce foliage, predisposing it to winter injury, which appears to be a major factor in the decline of montane populations of the species. Other studies have shown increases in calcium (Ca) concentration in canopy throughfall in montane spruce-fir forests, and decreases in foliar Ca concentration associated with exposure to acid mist. Studies of other plant species suggest that Ca may play a role in the development of cold tolerance or in stress response to cold. These considerations have led to the specific hypothesis that the reduction in cold tolerance associated with exposure to acid mist is caused by reduction in foliar Ca. To test this hypothesis, we applied Ca fertilizer to trees in a 33 year old red spruce provenance plantation in Colebrook, NH, and used branch chambers to expose individual branches to mist of known composition.