Influence of Manganese on Growth of Jack Pine and Black Spruce Seedlings

Analyses of foliage from natural stands of jack pine and black spruce confirmed earlier observations that levels of Mn were much higher in foliage of black spruce than in that of jack pine. Levels of Fe in jack pine foliage were greater than in black spruce.In a growth chamber experiment with spruce and pine seedlings and Mn supplied at 0, 0.1, 1, 10 and 100 ppm, both species grew best at the 0.1 ppm level and there was no evidence of difference in tolerance to high Mn levels. In this experiment, no marked species difference in foliar Mn concentrations was observed like that existing in natural stands. Possible reasons for this lack of difference are discussed.