Germination and early growth of four pine species on soil treated with simulated acid rain

Abstract

The effect of simulated rain solutions of pH 5.6, 4.0, or 3.0 [Formula: see text] on seed germination and early seedling growth of pitch pine (Pinusrigida Mill.), shortleaf pine (P. echinata Mill.), loblolly pine (P. taeda L.), and eastern white pine (P. strobus L.) was observed in a growth chamber on unsterilized soil from the New Jersey Pine Barrens that had been treated for 1 year with the acid rain solutions. Damping-off caused the death of all seedlings in the pH 3.0 treatments. Autoclaving the soil controlled damping-off. However, chemical changes in the soil increased the solubilities of mineral elements, and at pH 3.0 Al toxicity inhibited root growth of pitch pine and shortleaf pine. In spite of suppressed root growth, seedling top growth was significantly greater at pH 3.0 than at less acid treatments possibly owing to greater inputs of N and increased availability of mineral nutrients.