Jurkonis, N., Juknys, R. and Venclovienė, J. 2006. Relationship between Scots Pine Individual Tree Mortality and Tree Vigor Indicators in the Polluted Environment. Baltic Forestry, 12 (2): 184-191

Dependence of individual tree mortality probability on tree growth intensity (diameter increment) and crown defoliation is analysed in the article. Even-aged Scots pine (Pinus sylvestris L.) forests, located in the surroundings of one of the biggest air pollution sources in Lithuania, mineral fertilizer plant ‘Achema’ (55°05.N; 24°20.E) were the main focus of these investigations. Multiple growth dependent logistic individual tree mortality models were elaborated and it was established that the tree mortality probability increases exponentially along with an increase in crown defoliation, however the rate of increase is rather different at different stand age and at the different diameter increment. In general, at the same defoliation level the probability of individual tree mortality was detected to be much higher for trees of lower growth rate, i.e. for trees of lower vitality. However, the relative increase in tree mortality probability with an increase in crown defoliation was faster for trees of higher growth rate. The impact of crown defoliation on the tree mortality rate increases with the aging of stands. Tree mortality probability exponentially decreases along with increase of tree growth rate (diameter increment); however for damaged (defoliated) trees dependence of tree mortality probability on the intensity of tree growth is much less pronounced.

Key words: polluted environment, tree growth, individual tree mortality, crown defoliation