Tree-ring analysis for the assessment of anthropogenic changes and trends.

Investigation of Pine (Pinus sylvestris L.) annual radial increment (width of annual tree rings) was carried out in the surroundings of one of the largest pollution sources in Lithuania - Jonava Nitrogen Fertilizers Plant. The main objective of investigation was to analyse different sides of anthropogenic transformations of tree-ring series in the polluted environment: changes in tree growth intensity: variance changes in tree-ring series: changes in the relations with natural external factors. Three different periods of tree reaction to the environmental pollution were singled out - fertilization period, depression period and recovery period since annual emissions were essentially reduced. The variance of tree-ring series has increased several times in the polluted environment. Reaction of trees to the impact of climatic factors (temperature, precipitation) has changed significantly in the polluted environment and their sensitivity has also increased.