Abstract: The tree ring width, pH value, wood chemical composition and element contents of poplars selected from healthy and acid rain damaged forests were analysed to evaluate the possible impacts on wood properties. Acid rain affected tree growth slower, tree-ring width narrower, tree-ring width of diseased tree decreased 12.67%. The pH values did not significantly differ. Compared with healthy trees, the content of holocellulose in diseased tree decreased 3.45%, but pentosan and lignin contents in diseased trees were higher than in healthy trees. Extractive content between diseased trees and healthy trees showed significant difference. The contents of K, Na, Ca, Mg in diseased trees were lower, but the content of Cu and S in diseased trees were significantly higher. Soluble sugars content in diseased trees was higher than in healthy trees. The results showed that there were a lot of differences in wood chemical properties between diseased trees and healthy trees.

Key words: Acid rain, Poplar clone I-72, Tree ring width, Chemical properties