Response of seed germination of Acer saccharum, Acer rubrum, Betula lutea, Tsuga canadensis and Pinus strobus to several substrate acidity levels was measured. Germination inhibition was observed at pH 4.0 and 3.0 for A. rubrum and at pH 3.0 for B. lutea compared to controls at pH 5.6 but no inhibition of A. saccharum or T. canadensis was observed at these levels. Germination stimulation of P. strobus occurred with decreasing substrate pH; maximum germination was recorded at pH 3.0-2.4. These findings indicate that a wide range of sensitivities of seed germination to acidic substrate conditions exists among five tree species characteristic of Adirondack mixed hardwood conifer forests. Interpretation of the results in relation to natural forest conditions requires an understanding of biotic and abiotic factors which influence seed germination and seedling establishment. Germinating seeds which inhabit the forest floor stratum may be protected from sudden or severe changes in substrate pH. Studies of sensitivity of seedling development and growth are required to determine the susceptibility of tree species to possible acid precipitation influence. © 1982.
Raynal, D. J., Roman, J. R., & Eichenlaub, W. M. (1982). Response of tree seedlings to acid precipitation- I. Effect of substrate acidity on seed germination. Environmental and Experimental Botany, 22(3), 377–383. https://doi.org/10.1016/0098-8472(82)90030-2