부산대학교 도서관

A two-step method was developed to estimate the economically available biomass from forest operations in the Pacific Northwest. Step one measures the amount of biomass in piles from a variety of logging operations. Step two applies logistics models to determine the amount of biomass at is recoverable at variable various extraction costs. Cable units included the biomass piles located at the landings; while ground-based units computed the collection and transport of each pile to the most cost-effective landing using GIS and simulation tools. This approach was applied to operations on private timberlands Oregon and Washington. For the cable logging units, the average pile size was 46.7 green tonnes of residue and this material was either on or next to the landing. It produced few large piles with an average of 24.75 green tonnes per ha. For ground-based operations, approximately 54% of the residue in the harvest units was 90 m or less from the landing. Collection cost increases as the material is farther from the landing; collection cost range between about $17.6 per green tonne at distances of 15.2 m to $37 per green tonne at distances of 213 m from the landing. Depending on the distance from the landing to the bioenergy facility it is possible to estimate how far from the landing into the forest to reach to collect the biomass.