Phenomenon of Trunk Twist during the Growth of Woody Plants (Using the Example of <Emphasis Type="Italic">Pinus sylvestris</Emphasis> L. and <Emphasis Type="Italic">Picea obovata</Emphasis> Ldb.)

The phenomenon of trunk twisting in Pinus sylvestris L. and Picea obovata Ldb. during a vegetation period has been revealed and described by direct measurements. The frequency of this phenomenon, magnitude, and direction of twists and their 2-year dynamics have been studied on five sample plots located in different forest-growing conditions. The average rotation angle is 0.2°–0.5°, while its maximum values reach 1.3°–1.7°. These characteristics depend on forest type and weather conditions. Next year more, than half of the trees change their twisting direction to the opposite one, whereas 8–19% of pine trees keep it unchanged. Based on an analysis of our results and the data of other authors, a qualitative model of morphogenetic processes has been proposed to explain the mechanism of this phenomenon.     

Rotational Activity of Trunk Parts in Scots Pine Trees: Seasonal Dynamics and Patterns

Doklady Biological Sciences - The seasonal dynamics and relationships between the characteristics of the angles of rotation of outer sapwood layers in trunks of Scots pine (Pinus sylvestris L.)...