Healing rate of logging wounds on broadleaf trees in Hyrcanian forest with some technological implications.

Abstract

The wound healing rate (WHR) was investigated in 234 wounded trees in Iranian forests and was found to range from 6.4 to 24.0 mm·yr -1 . Tree species, slope aspect, elevation, wound age, and wound type had significant effects on the WHR. The mean of the WHR in the Fraxinus excelsior (24 mm·yr -1 ), Alnus subcordata (18.9 mm·yr -1 ) and in the Fagus orientalis (17.9 mm·yr -1 ) were significantly higher than in the Acer insigne (15.7 mm·yr -1 ), Acer cappadocicum (14.6 mm·yr -1 ), Carpinus betulus (13.7 mm·yr -1 ), and Tilia begonifolia (6.4 mm·yr -1 ). In addition, the mean of the WHR on northern slopes (17.5 mm·yr -1 ) was significantly higher than on southern slopes. Moreover, the parameters that positively influenced tree growth showed a similar effect on the wound healing rate. The WHRs of 5-, 10- and 15-year-old wounds were 19.3, 16.9 and 10 mm·yr -1 , respectively. The WHR increased the higher the wound from ground level. The WHR for horizontal wounds (18.4 mm·yr -1 ) was significantly higher than for vertical wounds. The highest WHR was estimated in a stand with a canopy closure of 60-80%. The WHR decreased according to increasing wound width. Wounds affect future income, lowering the number of trees that potentially provide a higher quality of saw and veneer logs.