Domestic large-diameter log use in the Japanese lumber manufacturing industry: focusing on regional differences

ABSTRACT

Japan’s postwar policies with respect to forestry management have led to the aging of planted forests and a shift toward large-diameter logs that has created a challenge for how to use such logs in the lumber manufacturing industry. In recent years, medium-diameter logs have been the predominant type, and there has been less demand for large-diameter logs. This study examines the Japanese lumber manufacturing industry’s consumption of domestic timber using survey data from 21 member companies of the Domestic Timber Sawmill Association. The results suggest that regional characteristics and the tree species consumed are the two main factors that drive the decision to use large-diameter logs. While current demand for large-diameter logs is considered low, the results show that demand is present, and there are signs of growing consumption of these logs within the lumber manufacturing industry. As the current machinery that handles medium-diameter logs depreciates, it is expected that companies will respond by either introducing machinery that can accommodate large-diameter logs or changing their products.

KEYWORDS:

• Large-diameter logs
• domestic timber
• lumber manufacturing
• kokusan-zai seizai kyōkai [domestic timber sawmill association]
• log consumption

Acknowledgments

This research was supported by grants from the Project of the Bio-oriented Technology Research Advancement Institution, NARO (the special scheme project on advanced research and development for next-generation technology). We would like to thank Dr. Satoshi Tachibana (University of Tsukuba) for his useful comments. We received cooperation from many companies in response to the survey used in this study. We would like to extend our thanks for this opportunity. We also owe much to the useful advices and comments of the anonymous reviewers and editors.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Notes

1. High quality decorative logs (yakumono) are utilized mainly for Japanese-style room (washitsu). The consumption amount of high quality decorative logs also has decreased. This is not so with medium-quality large-diameter logs (lack of basic demand as a material) but is due to the change of housing style, for example, from wall with exposed timber pillars (shinkabe) to wall bearing no exposed pillars (ookabe).

2. Eight regional categories are included: Hokkaido in Hokkaido; Aomori, Iwate, Miyagi, Akita, Yamagata, and Fukushima in Tohoku; Ibaraki, Tochigi, Gunma, Saitama, Chiba, Tokyo, and Kanagawa in Kanto; Niigata, Toyama, Ishikawa, Fukui, Yamanashi, Nagano, Gifu, Shizuoka, and Aichi in Chubu; Mie, Shiga, Kyoto, Osaka, Hyogo, Nara, and Wakayama in Kansai; Tottori, Shimane, Okayama, Hiroshima, and Yamaguchi in Chugoku; Tokushima, Kagawa, Ehime, and Kochi in Shikoku; and Fukuoka, Saga, Nagasaki, Kumamoto, Oita, Miyazaki, Kagoshima, and Okinawa in Kyusyu. These categories were used in Table 3, Table 4, Table 5, Table 6, Table 9, and Table 10.

3. The benefit from timber production is low, therefore it is difficult to recoup enough money to reinvest (reforestation), and consequently the reforestation rate is low.

Additional information

Funding

This work was supported by the NARO Bio-oriented Technology Research Advancement Institution [the special scheme project on advanced research and development for next-generation technology].