ANALYSIS OF CHANGES THE COST OF AVERAGE INCREASE OF TIMBER AND THE AVERAGE INCREASE OF LARGE AND MEDIUM TIMBER IN SPRUCE BY AGE
Research of the dynamics the economic and technical maturity in spruce stands is made on the basis of taxation data 336 sample plots. There are include the spruce forest element 40 years and older. All sample plots were divided into groups by scale index - I<sup>a</sup>-IV. I<sup>a</sup>-III scale index were further divide into two groups based on stocking level of sample plots - up to 0.85 and more than 0.85. Analyzing the dynamics the cost of average increase of timber we can conclude that with decreasing productivity of the spruce forest element the age of maximum increases from 72 to 183 years. It is also worth noting that economic maturity age of the stands with less stocking level comes earlier than the stands with a large stocking level. Analyzing the dynamics the average increase of large and medium timber we can conclude that economic maturity characterized by higher maturity age than technical maturity. Technical maturity age gradually increasing from 69 to 123 years with decreasing the scale index from I<sup>a</sup> to IV. Between groups of stocking level the trend of higher technical maturity age of the stand with less stocking level is not identified in comparison with economic maturity. Economic maturity is better for forestry because it include the assessment of timber cost and achieves maximum monetary profit from the stand.