Relative Tree Height in Isolated Populations of Pine Stands

The study of relative tree height in lingonberry, bilberry and sphagnum pine forests on Bolshoy Solovetsky Island was carried out. The island is the largest by area in the Solovetsky Archipelago and in the White Sea. The archipelago is a UNESCO World Heritage Site. Relative height is an important indicator characterizing the growth of woody plants and reflecting how many centimeters of height growth for each centimeter of diameter. We laid 34 sample plots in the most widespread forest types - lingonberry, bilberry, and sphagnum pine forests, occupying 82.0 % of the total pine forest area. At each sampling area we selected survey trees (64 trees each), measured heights, diameters, and took cores with an age drill the root neck to determine the age. A total of 2176 trees were used in the relative height analysis. The average relative height in lingonberry, bilberry and sphagnum pine forests on Bolshoy Solovetsky Island is 62.5; 61.5 and 54.7 cm/cm, respectively. This relative height is noticeably lower than in pine forests on the mainland in the Arkhangelsk Oblast. There, the values are 84.9; 84.9 and 79.2 cm/cm for the respective forest types. It is not possible to use the existing growth progress tables developed on the basis of mainland trees for island pine forests. Equations for determining the relative height of pine forests on Bolshoy Solovetsky Island were obtained. It is proposed to use tree diameter rather than age as an input parameter, since the determination of age is much more difficult than that of diameter at breast height.