Prediction of branch variables related to timber quality in Pinus sylvestris

Abstract

Single‐tree functions to predict the diameter of the thickest living branch and the branchiness (the proportion of the cross‐section area of branches to the stem‐surface area) based on the relative tree height for the live crowns of standing trees are presented. The study also considers the diameter of the thickest dead branch, the cross‐section area of branches, and the stem‐surface area using data from temporary sampling plots in southern Sweden. The diameter of the thickest living branch correlated closely with the stem diameter near this branch. The diameter of the thickest living branch decreased from crown base and upwards. The diameter of the thickest dead branch increased to a relative tree height of about 50%, and then decreased beyond. For a biological diameter of the thickest living branch modeling approach, the residuals indicated no major trend and the root mean square error (RMSE) value was rather low. The branchiness was predicted by variables describing the size of branches, the number of branches per whorl, the distance between whorls and by the stem‐surface area. In the for timber marketable part of the stem, the branchiness increased with increasing relative tree height.

Key words:

• Branchiness
• crown
• relative tree height
• Scots pine
• Sweden
• thickest branch