The specifics of growth and productivity of young pine stands, formed of the trees of the different cenotic position

Abstract

The results of the formation of overstocked 15­year pine stands (with initial density of trees 35.6 thousand per ha) in the Krasnoyarsk forest­steppe the thinning aimed at reducing their density with keeping only the trees of a certain cenotic position (dominant, co­dominant and suppressed) in order to obtain information about the possible equalization of their forest inventory indicators in the process of their growth are presented. It was found that after thinning the dominant trees stand had density of 4.3 thousand per ha, had the best growth characteristics (mean height and mean diameter) and upheld that tendency through the whole observation period. After 7 years mean diameter of dominant trees increased from 4.8 ± 0.1 to 9.4 ± 0.2 cm, mean height increased from 4.8 ± 0.1 до 8.1 ± 0.1 m. Stem timber volume increased 5.0 times to the value of 141.63 m3 per ha, relative density – from 0.51 to 1.27. Stand density for co­dominant trees decreased to 6.6 thousand per ha after the thinning. The mean diameter of co­dominant trees increased 2.6 times and amounted 6.1 ± 0.1 cm, the mean height increased from 3.4 ± 0.1 to 5.7 ± 0.1 m. Stem timber volume increased from 7.92 to 60.06 m3/ha, relative density increased 3.7 times (1.00). After the thinning the suppressed trees underwent a long (1–2 years) adaptation period, had disproportional growth in height and decreased growth in diameter (relative height 244). Stand density for suppressed trees pine Pinus sylvestris L. decreased to 6.3 thousand per ha after the thinning. The mean diameter of the suppressed trees after 7 years after the thinning changed from 0.9 ± 0.1 to 4.2 ± 0.1 cm, the mean height – from 2.3 ± 0.1 to 3.8 ± 0.1 m. Timber volume increased from 1.09 to 17.23 m3 per ha, relative density increased from 0.07 to 0.69.

Keywords

• scots pine
• young stands
• thinning
• density
• dominant trees
• wood increment