Изменения климата и состояния лесов Республики Марий Эл в ХХ столетии

There had been done the analysis of long-term data on dynamics of atmospheric factors, radial annual growth of trees and forest stand productivity. It is proved that during the last half of the century the middle-aged and maturing forest stand productivity of dominant species in Mari El has increased considerably, though it happened not only due to climate change. Estimation of climate change influence on state and forest productivity is closely linked to many methodical difficulties.