Effects of simulated acid rain on sugar maple seedling root growth

Abstract

Based on studies of seedling microhabitats in the field, laboratory experiments were conducted to determine the effects of brief pulses of simulated acid rain on sugar maple ( Acer saccharum Marsh.) seedling root growth. Radicle elongation following seed germination was reduced at pH 3.0 1 day after germination but not after 3 days or more. After 7 days of growth, seedlings exposed to pH 3.0 showed a significant reduction in growth of root hairs compared to those exposed to pH 4.0 rain; however, no significant differences in radicle and root hair growth were found 10 days after seed germination. The growth of the primary and secondary roots was not affected by exposure to simulated acid rain of pH 3.0. Evaluation of the findings in relation to natural conditions indicates that generally no direct adverse effects on sugar maple seedling growth are expected.