Effect of logging wounds on diameter growth of beech (Fagus orientalis Lipsky) trees following selection cutting in Caspian forests of Iran

Abstract

Background: Logging damage to residual trees during selection cutting may lead to serious economic losses in terms of both timber quality and diameter growth reduction. In this study, we investigated the effect of logging operations on residual tree damage and the consequence of injuries on diameter growth in an uneven-aged mixed forest dominated by beech (Fagus orientalis Lipsky). Methods: The diameter growth of 56 wounded and 56 unwounded beech trees were compared 12 years after selected logging of other trees had taken place in an Iranian Caspian forest. Results: Of total logging wounds, 25.0 % (14 wounds) were caused by felling operations and 75.0 % (42 wounds) were caused by winching operations. The reduction in diameter growth of wounded beech trees was only observed in the breast height DBH range below 55 cm. The diameter growth of wounded trees was 8.1 % lower than in unwounded trees. The vertical distance from the ground of wounding was a significant factor in diameter growth. Wounds that were larger than 200 cm2 in area significantly reduced diameter growth of beech trees. Whether wounds were closed or open wounds had no significant effect on diameter growth but decayed wounds reduced diameter growth by 15.3 %. Conclusions: This study suggested that intensive logging wounds reduce diameter growth, especially in young beech trees. In addition to the intensity, size and position of wounds and tree age, the reduction of diameter growth was related to the ratio of wound size to stem area.