Stem Volume and Quality of Hybrid and Common Aspen in the Clonal Archive

Abstract

Hybrid aspen as a fast growing tree species with short rotation is of interest for the creation of plantation forest crops in intensive forest management. Hybrid aspen wood is used to produce paper, lumber, and plywood, as well as biofuel. The research purpose is to compare the volume and quality of the stem of hybrid and common aspen, and to assess interclonal variability by these features in cold climate areas. The research results of 42 hybrid and 10 common aspen clones in the clonal archive of the Institute of Biology of Komi Scientific Centre of the Ural Branch of the Russian Academy of Sciences are presented. The archive was laid out in 2009 by 1-year-old rooted seedlings with a closed root system with the placement of plants 3×3 m. Donor plants were obtained at the Haapastensyrjä Tree Breeding Station of the Natural Resources Institute Finland. Scales have been developed for assessing plant health and stem straightness. Herewith, the height of trees, the presence of sores, scars and frost clefts on their stems were recorded. The share of tree-like and shrub-like plants was 70 and 5 %, respectively, with an average survival of 75 % at the 10-year biological age. Hybrid aspen was statistically significant in terms of superiority to standard aspen in diameter by 65 %, height by 49 %, and stem volume by more than 3 times. The share of slightly crooked stems was about 7 %, and the share of stems with bark cracks was about 3 %. Good survival, stem quality, and rapid growth of hybrid aspen made it possible to conclude that it is a promising species for plantation reforestation in the taiga zone.