Impact of Sulphur and Nitrogen Dioxide Concentration on Radial Increment Dynamics of Scots Pine (Pinus Sylvestris L.) Growing in Cities

Trees growing in city forest parks and parks are exposed to permanent higher air pollution level than trees growing in relatively clean environment. Investigation of tree response towards changes in acidifying pollutant’s (SO 2 and NO 2 ) concentration dynamics is relevant, as forest parks and parks fulfil many beneficial functions in cities. Scots pine ( Pinus sylvestris L.) sample trees, growing in parks and forest parks in Vilnius and Kaunas cities, were chosen as the objects of this research. Wood samples were collected from 330 sample pines in 15 sample plots in Kaunas city and from 480 sample pines in 20 sample plots in Vilnius city . Dendroscales of radial increment of pines growing in cities were transformed into sequences of radial increment ratio, in order to eliminate the impact of tree age without removing the negative impact of anthropogenic pollution. Reduction of NO 2 and SO 2 concentration in the atmosphere could determine the increase of pine radial increment in 1990–2006: significant relation was estimated between radial increment and NO 2 concentration in Vilnius and Kaunas cities (mean correlation coefficient r was equal respectively – -0.61 and -0.62, p 2 – in Vilnius city ( r =-0.65, p Climatic factors determined greater part of complex impact (74–88 %) on pine radial growth in comparison with concentration of acidifying pollutants (12–26 %) in 1990–2006 year period.