Comparative characteristic of three types of forest plantations of siberian stone pine in the Tomsk region

In the subzone of the southern taiga in the territory of the Tomsk region trial plots in forest cultures under the canopy of the forest have been laid, the reconstruction of low-value plantings and subsequent crops has been done. Biometric indicators have been studied and a comparative analysis of three types of plantations has been made. It is revealed that the growth of artificial plantations of Siberian stone pine is largely influenced by competition from adult trees in the main canopy in sub-cultures and in artificial plantations created during the reconstruction process. The preservation of sub-negative cultures has varied from 55.6 to 64.4% at 43 years old age and has been 59.8% at 32 years old age. Sub-negative plantations on the test plot with greater density have considerably lagged behind in growth from the sites with lower density with other identical growing conditions and age. Preservation of forest plantations created by reconstruction in areas without a main canopy has amounted to 72.6%, on a plot with an adult stand - 46.8%. The diameter of the trees on the reconstruction without the main canopy has been 2.1 times different, the height - 1.8 times in favor of the plantations in the area where the low-value plantation have been cut down. In subsequent plantations, in those test plots where pure pine tree plantations have been preserved, the height and diameter of the trees has been also greater than those in the samples with the existing admixture of hardwoods. In general, subsequent plantations significantly exceed the growth of subordinate and reconstructed crops. The growth of sub-cultures is significantly affected by the competition of the root systems of adult plants of the main canopy, shading and lack of nutrients.