Strip road impact on selected wood defects of norway spruce (Picea Abies (L.) H. Karst)

Creating strip roads in second age class stands is an indispensible operation for carrying out thinning.It is especially important in places where there is an intention to do a first thinning using mechanised thinning operations.Felling trees to create strip roads results in altered conditions for the tree growth of neighbouring trees.In particular, this is due to an increase in exposure to sunlight.This can lead to changes in the growth of trees and consequently changes in the morphology of the trunk and the development of defects.The objective of this paper was to analyse the frequency of the presence of particular defects in the structure and shape of spruce in a five-year period after the creation of a strip road.The research was carried out in an artificially regenerated spruce stand within the spruce's natural, northern habitat in Poland.A 34-year-old stand underwent a systematic thinning scheme which involved the removal of every eighth tree row.The analysis was carried out on trees growing both adjacent to the strip roads (which had a greater growing area around them and greater access to sunlight) as well as trees from further within the stand.Diameter growth was taken in three places: at breast height, in the middle of the trunk between breast height and the base of the crown, as well as at the base of the crown.The average incremental growth, pith eccentricity taper and ovality were calculated.No statistically significant difference in defects between the trees growing by the strip road and those growing further in the stand was observed.Greater taper on mid-tree logs in comparison to butt logs was observed.Insignificant changes in the morphology of the trunks, supports the validity of cutting strip roads in second age class stands.