Impact of shelterwood regeneration method on mechanical properties of scots pine wood

Abstract

Regeneration method effects within-stem variability of mechanical wood properties but has no impact on overall quality of Scots pine logs. In Central Europe, group shelterwood regeneration method relying on natural regeneration is generally considered as an approach that meets the criteria of close-to-nature silviculture. We tested its effect on wood properties in contrast to the clearcutting method with subsequent artificial regeneration by planting in the case of Scots pine (Pinus sylvestris L.). Four localities were chosen in the Czech Republic, where both regeneration methods were applied. Sample trees were felled and subsequently evaluated for the impact of the applied regeneration method on wood properties. Modulus of elasticity, bending strength and wood density were used as indicators of wood quality. The impact of the regeneration method on the examined characteristics of the wood was not statistically significant, 78 MPa (megapascal) for shelterwood and 75 MPa for clearcutting method in the case of bending strength, and they are of negligible importance in terms of influencing end-product potential. Much more significant was the impact of the applied regeneration method on the distribution of the properties along trunk radius, where the shelterwood method provides even distribution. Non-destructive methods turned out to be useful tools for elastic properties estimation of wood as the close correlation to modulus of elasticity was confirmed (r = 0.66 and r = 0.82 for shelterwood and clearcutting method, respectively).