Radial growth response of Scots pine to climate under dust pollution in Northeast Estonia

Dendrochronological techniques were used to investigate the influence of climatic factors on the radial growth of Scots pine ( Pinus sylvestris L.) under the impact of dust pollution in the industrial region of Northeast Estonia. Study sites Narva-1 and Narva-2 suffer dust pollution stress from oil shale fired power plants located in this region. The impact of climate on radial growth of pines at three study sites was modelled using response function analysis. Tree-ring indices chronologies for each study site were compared using regionally averaged temperature and precipitation data sets for the period 1946-1991. Among temperature variables significant predictors of radial growth along with the temperature of winter months, generally limiting the growth of pines in this region, are midsummer temperatures of the current year and temperatures of the previous growth season. For each site a different set of precipitation variables limiting growth was detected. Only an optimum amount of precipitation during the previous summer has a positive effect on radial growth on all sites. An increased importance of precipitation to the radial growth in dust-polluted sites was detected.