The effect of acid rain on the annual growth of Pinus strobus and Acer rubrum.

Abstract

Acid deposition, a side effect of human advances in industrial and agricultural technology, is now known to affect multiple components of ecosystem health on both a local and multiregional scale. Our study investigated the effect of wet acid deposition on the growth of two tree species: Pinus strobus (eastern white pine) and Acer rubrum (red maple). We predicted that eastern white pine would grow an equal or greater amount when acid deposition was high because of its high tolerance of acidic soil conditions. In addition, we predicted that red maple would grow less when acid deposition was low because it prefers environments with a higher pH. We found no significant correlation between wet acid deposition and mean annual ring growth, regardless of species or season of deposition. Positive and negative correlations between growth and acid deposition were noted among a few individuals in the populations. The lack of signfiicant correlation may be due to varying results may be attributed to difficulties in defining acid deposition, differences in the buffering capacity and nutrient levels of an environment, the amount of acid deposition dropped on a specific environment, and genetic variation of individuals in a population.