Influence of Climatic Factors on Annual Rings of Conifers

Relationships of the width of annual rings of 75-85-year old Pinns sylvestris L. and Picea abies (L.) Karst, with average monthly temperature, amount of precipitation and a complex climatic indicator developed on their basis was studied against the background of pollution load in the zone influenced by a cement plant and in a control area. Multiple regression analysis (equations with two and three independent variables) showed a significant correlation between precipitation and temperatures with increment, especially for pine: however, the prediction capability of the models is modest, describing usually 35-40% of the variation in radial increment. The calculations suggest that precipitation amounts are more important and temperature parameters less important and can be replaced by one another in the models. A direct correlation with the pollution load can be observed: at probability (P) near zero the coefficients for precipitation were the highest (0.45-0.51) in the area strongly affected by the cement plant and the lowest (0.31 -0.35) in the weakly affected and control areas. In case of spruce shortage of air humidity during summer months was important for increment, especially so in the heavily polluted area.