Estimating harvest costs and projecting quantities of logging residues for small-scale forestry in Nasushiobara, Tochigi Prefecture, Japan

摘要

We used GIS on a regional scale to estimate and compare supply potentials and costs of small-scale logging systems, a mini-forwarder and a 4-ton truck operated by private logging contractors, and manual logging and a light truck operated by individual forest owners, with the mechanized operational system of the Forest Owners' Association. Total potential yields of timber and logging residues were estimated as 418,895 m3 and 254,962 m3, respectively. The economic balances were estimated and available amounts were projected as supply potentials from profitable sub-compartments. As a result, available amounts of timber and logging residues were estimated at 376,466 m3(89.9%) and 203,850 m3(80.0%), respectively. Because their transport expenses were lower than for other systems the most profitable sub-compartments were operated by private logging contractors who sold logging residues at a plant. The profitable sub-compartments operated by individual forest owners were few because the extracting distances were usually greater than 20 m. Raising logging residue prices from 3,000 yen?m-3 to 4,080 yen?m-3 or 6,800 yen?m-3, and establishing forest roads, which reduced some extracting distances to less than 20 m, increased the number and area of profitable sub-compartments, and increased available amounts of logging residues.