Foliar elemental composition of spruce-fir in the southern blue ridge province

Data are presented for what we believe to be the first assessment of the elemental foliar status of red spruce (Picea rubens Sarg.) and Fraser fir [Abies fraseri (Pursh.) Poir.] trees in the high elevation forests of the southern Appalachian mountans. Needle samples were collected from September–November 1984. Needles were separated according to flush year for the 1984, 1983 and 1982 growing seasons. Each sample was analyzed without washing for 28 macro- and micronutrients and trace elements. Significant differences in foliar concentrations were observed between flush year for N, P, Ca, Mg, K, Cl, Cu, Ce, Th, Cs, Pb, Fe, La and Rb for Fraser fir (n=41), and P, Ca, K, Cl, Cu, Pb and Rb for red spruce (n=30). Nitrogen concentrations ranged from 11.2–20.2 mg g^?1 for Fraser fir, and 8.7–15.9 mg g^?1 for red pruce. The mean concentration of Ca observed in red spruce needles (1.4 mg g^?1 1984 growing season) fell at the low extreme of reported values for non-necrotic red spruce foliage in the northeastern United States (1.2–11.6 mg g^?1). The mean concentration of Ca in Fraser fir foliage (3.4 mg g^?1, 1984 growing season) was also lower than reported values for eastern fir, but not to the extent demonstrated for red spruce. Fraser fir needles had higher concentrations of Al than red spruce (310vs 91 mg kg^?1, respectively, 1984 growing season), but both values are higher than those reported for spruce or fir from the northeastern United States. Calcium:aluminum ratios in current foliage are the lowest yet reported for the eastern spruce/fir forest type, suggesting that Al toxicity and/or Ca deficiency may be important stresses in these stands. Comparison of Pb concentrations with those of other rare-earth elements known to be associated with dust on needle surfaces (Ce, La, Sc, Sm, and Th) suggested that a substantial portion of the Pb found was due to particulates on the needle surfaces. The significance of these results to the observed forest decline syndrome in high elevation forests of the eastern United States is also discussed.