Abstract:

Selected trees from healthy and different acid rain and air pollution damaged class (Pinus massoniana) forest were analysed for their water, basic density, chemic composition and element content as well as for their content of soluble sugars and starch to evaluate the possible impact on their wood properties. They were performed year ring-wise. The sapwood and heartwood portion of damaged trees showed a lower water content than that of healthy trees, in addition the sapwood and heartwood portion of serious damaged trees were about 30% and 20% less, but the basic density between different damaged class trees did not significantly differ. The chemical composition of different damaged class trees showed significant difference; the lignin and extractive content in damaged trees was higher than that in healthy trees; however, the α-cellulose content was about 1% to 3% less. The content of glucose in trees growing serious damaged forest were lower about 2% than that in healthy foreast ones. The content of sodium, calcium, magnesium, aluminium, iron, titanium and zinc differed between healthy and damaged trees of the same site; especially, the content of aluminium and iron was about one time and zinc was about three times higher than that in healthy trees. The content of soluble sugars and starch in damaged trees was lower than that in healthy trees. Those results indicate that there are lot of difference between the wood chemical properties of the trees from acid rain and air pollution damaged forest and healthy forest.

Key words: Acid Rain, Air pollution, Wood properties, Pinus massoniana