The measured content and storage of trace elements in each parts of larch trees was Zn>Cu>As>Pb>Cd,which has positive correlations with that in soil.During the leaf falling period,a about 6% of Zn in leaves was transferred to trunk,branch and root.A general increase in Zn storage was observed demonstrating an obvious internal cycling rate Zn of 25% of the gross cycling.The cycling of Cu,Pb,Cd and As were almost external,and waried from 20%～71% of gross storage in trees and their cycling rates were 30%,68%,...