Salvage cable yarding operations productivity of pinewood nematode infected Pinus trees in South Korea

Abstract

ABSTRACT Salvage logging of nematode-infested pinewoods could increase in South Korea, because of the risk of pest spread in response to climate change. No previous studies have precisely determined how to extrapolate information regarding cable extraction productivity and cost in salvage logging operations to steep terrains in South Korea. Therefore, in this study, the performance of a semi-mechanized system was observed at two different harvesting sites located in areas affected by the pinewood nematode (Bursaphelenchus xylophilus). The following were the specific aims of this study: (1) to evaluate HAM200 yarder productivity and cost in four different conditions (50 and 100 m yarding distances in uphill and downhill directions), and (2) to identify significant independent variables related to productivity. The HAM200 productivity values varied considerably and ranged from 1.95 to 2.52 m3/productive machine-hour (costs 43.29–55.81 US $/m3, respectively). Overall, productivity for trees damaged by uphill yarding was 20% higher compared to downhill yarding while productivity was not significantly different. Yarding direction, lateral distance, volume per cycle, and interaction of volume per cycle with lateral distance significantly affected the productivity. Further, our regression model, uphill yarding should be favorable from 35 to 100 m yarding distances. The findings of this study would enable better planning and decision-making regarding salvage logging, thereby allowing improved production of damaged trees.