ИСТИНА

The problem of air pollution and its effects on the natural environment or particular ecosystems is one of the greatest global challenges faced by mankind. The earlier studies [1] proved that Pinus sylvestris L. and Picea abies L. are good indicators of background environment state. It was shown that particularly for northern and central parts of European Russia there is significant correlation between wet deposition and tree stands conditions. Our research was performed in areas of Russian ICP IM sites RU04, RU16, RU13, located at Russian national reserves (RU04– Oka-Terrace Biosphere Reserve, RU13– Central-Forest Biosphere Reserve, RU16– White Sea Biological Station). The main objectives were to evaluate defoliation and discoloration of Pinus sylvestris L. and Picea abies L. stands. The main goal of presented study was to recognize whether some tendencies could be determined in measured parameters or not. The MAKESENS tool with realized Mann-Kendell test and Sens-slope application for trend estimation was used for time series analysis. There are no co-directional trends for those parameters found for whole data sets. Two trends of high significance were identified only (one increasing and one decreasing) allowing to suppose that air quality at RU04 is getting better while in contrary, state of environment at RU13 is getting worse. For both cases Pinus’s stands seem to be more sensitive to air quality conditions, and it corresponds to earlier studies for the same territories. The short data series and rare (or absence of) measurements during 1990s for other parameters did not possibly allow to disclose any significant trends.