A Comparison of Felling Techniques on Stump Height and Log Damage with Economic Interpretations

This study investigated two of the many potential sources of value loss that occur during logging operations: stump heights and butt log damage. The potential value loss was determined for manual felling and five different felling heads for logging sites located in the central north island of New Zealand. Manual felling produced the highest stumps and three different felling heads (Hultdin, Timbco, and Warratah) produced second highest stumps. The group with the lowest stumps was felled with AFM Magnum and Koehring felling heads. The Warratah felling head had the lowest incidence of butt log damage, while manual felling had the highest proportion of damaged butt logs. The majority of the damage to the butt logs was slabbing damage; all felling techniques produced little stump pull damage. A comparison of the potential value loss showed that the Koehring produced the lowest potential value loss at US$128/ac, while manual felling had the highest potential value loss at over US$420/ac. West. J. Appl. For. 15(2):59-61.