Costs of harvesting forest biomass on steep slopes with a small cable yarder: results from field trials and simulations
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In: Smith, Wayne, H., ed. Biomass energy development; Plenum Publishing Corporation, 1986: 133-142.
Cable yarding can reduce the environmental impact of timber harvesting on steep slopes by increasing road spacing and reducing soil disturbance. To determine the cost of harvesting forest biomass with a small cable yarder, a 13.4 kW (18 hp) skyline yarder was tested on two southern Appalachian sites. At both sites, fuelwood was harvested from the boles of hardwood trees 10 to 36 cm (4 to 14 inches) in dbh. The volume of pieces yarded ranged from 0.01 to 0.63 m³ (0.2 to 22.4 ft³). With a crew of four on a small clearcut block and piece volumes averaging 0.14 m³ (5.1 ft³), yarding costs were $12.03 per m³ ($33.70 per cunit). With a crew of two on a site previously harvested for sawlogs, it cost $6.78 per m³ ($19.00 per cunit) to yard pieces averaging 0.21 m³ (7.5 ft³). Because productivity was generally constrained by the yarder's 429 kg (1,150 lb) mainline pull capacity, the two-person crew proved the most efficient. Production and cost analyses integrating field studies with computer simulation showed that the total cost of yarding biomass with a two-person crew could range from $5.50 to $11.00 per m³ ($15.00 to $31.00 per cunit), depending upon average piece volume. This analysis also revealed a tradeoff between biomass utilization and total yarding cost: costs can be reduced by limiting the minimum piece volume yarded.
KeywordsTimber harvesting, cable yarding, biomass, logging cost, simulation
Baumgras, John E.; LeDoux, Chris B. 1986. Costs of harvesting forest biomass on steep slopes with a small cable yarder: results from field trials and simulations. In: Smith, Wayne, H., ed. Biomass energy development; Plenum Publishing Corporation, 1986: 133-142.