Abstract:

With the endpoint of securing a steady supply of logging residue, this study projects the supply potential and availability of logging residue by using 2005–2011 forest management records and 2012–2016 forest management plans for the Takahara area of Tochigi prefecture, Japan. Forest management plans do not list thinning methods (such as those of a precommercial or commercial variety); therefore, the relationship between stand ages and commercial thinning operation rates is analyzed using forest management records, and commercial thinning rates are estimated with stand ages. Trends vis-à-vis supply potential and logging residue availability between 2005 and 2016 are examined: the supply potential of logging residue from precommercial thinning operations significantly increased between 2009 and 2010, on account of a new tax levied in April 2008; on the other hand, a steady supply of logging residue is projected by using forest management plans. In forest management plans, it is assumed that precommercial and commercial thinning operations are conducted within the same subcompartments. Therefore, the profitability of subcompartments can be improved with commercial thinning operations, and the available logging residue amounts from precommercial thinning operations are estimated in forest management plans. Meanwhile, no available logging residue amounts from precommercial thinning operations are estimated through the use of forest management records. The available logging residue amounts of aggregated stands are increased; by aggregating stands, the stand areas can be increased to more than 6 ha and be made profitable, even with longer forwarding distances.

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