The aim of this study was to examine Scots pine (Pinus sylvestris L.) xylem changes caused by heavy metal pollution. Annual rings width, number of tracheids in radial rows and the length of tracheids in the wood from trees growing on post-flotation tailings have been measured. Dimensions of tracheids have been examined separately for early- and latewood of each radial increment. The most demonstrable changes are observed in the tracheids length, which appears to be shorter in the xylem from the industrial area than in the control samples. In the wood from the polluted site, the variability of length of tracheids is increased. Microscopic observations revealed numerous deformations in the xylem tissue and deviations from the standard cell arrangement. Circumferential deformations occurring in the wood structure may indicate the increasing spring frost vulnerability of these trees.
