AGE DYNAMICS OF SPRUCE STANDS IN THE NORTHWESTERN RUSSIAN PLAIN BASED
The age dynamics of spruce, stands being at the final succession stages, are characterized. Based on the long-term (27-35 years) investigations on permanent sample plots, there were distinguished the following succession phases: stock stabilization, stock digression, and stock accumulation. The last two phases are divided into two subphases. The data on the different phases of age dynamics characterizing the structure of naturally developing forests enable to assess their stability in time and possibilities for the conservation of the necessary level of biological diversity.