Kuliešis, A., Saladis, J. and Kuliešis, A. A. 2010. Development and Productivity of young Scots Pine Stands by Regulating Density.  Baltic Forestry 16 (2): 235 – 246.

The key to the control of the productivity of Scots pine (Pinus sylvestris L.) is the regulation of stand density. The growth of two Scots pine stands of the forest type Vaccinio-myrtillosa has been observed in the course of 16 years. The initial age varied from 4 to 8 years, while the initial density was in the range of 5,400-8,100 trees/ha. Both stands are planted, one on former agricultural land and the second on former forest land. Ten plots with two replications of 5 treatments were established in each stand at the beginning of the experiment. Starting with 600 trees/ha, the initial density was increasing at each subsequent treatment with 500-1,000 trees/ha, ending with the control stand. The density was regulated to provide different conditions for competition during the time of the experiment. Each treatment was re-measured 4 to 8 times during the period of 13 to 16 years.
Growing of stands with 2,000-3,000 (4,000) trees per ha over the period of 7-19 years has a positive influence on the height growth of trees. The mean diameter increment of trees growing in the most intensively thinned stands (600 trees per ha) exceeds the mean diameter increment of trees in the control stand by 1.8-2.8 times. The ratio of the mean tree volume increment of intensively thinned stand to the control stand comprises 3.1-3.7 at the age of 17-24 years. Early and intensive thinning of pine stands resulted essentially decreased competition, increased growth and higher level of accumulated wood increment per stand. The study outlines the conditions enabling to achieve intensive growth of tree diameter and a higher level of yield.

Key words: forest stand density, diameter, height and volume increment, competition, yield level.