References
- Aruga K, Hiyamizu G, Nakahata C, Saito M. 2013a. Effects of aggregating forests, establishing forest road networks, and mechanization on operational efficiency and costs in a mountainous region in Japan. J For Res. 24:747–754.
- Aruga K, Mizuniwa Y, Uemura R, Nakahata C. 2015. Optimum bucking method for clear-cutting operations in Nasu Forest Owners’ Co-operative, Tochigi prefecture, Japan. Paper presented at: Proceedings of the 48th FORMEC Symposium 2015; Oct 4–8; Linz, Austria.
- Aruga K, Otsuka Y, Nakahata C, Yamaguchi R, Saito M, Nagasaki M. 2013b. Operational efficiencies and costs of an arm roll forwarder: a case study at Nasu in Tochigi Prefecture, Japan. J For Res. 24:577–583.
- Brunberg T. 2004. Underlag till produktionsnormer för skotare [Basis for forwarder productivity norms]. Redogörelse 2004:3. Uppsala: Skogforsk.
- Core Team R. 2015. R: A language and environment for statistical computing. Vienna: R Foundation for Statistical Computing.
- Fernandez-Lacruz R, Di Fulvio F, Bergstöm D. 2013. Productivity and profitability of harvesting power line corridors for bioenergy. Silva Fenn. 47.
- Hijmans R. 2015. Raster: geographic data analysis and modeling. R package version 2.5-2.Available from: http://CRAN.R-project.org/package=raster.
- Holm S. 1979. A simple sequentially rejective multiple test procedure. Scand J Stat. 6:65–70.
- Japanese Forestry Agency. 2010. Annual report on forest and forestry in Japan fiscal year 2009 (Summary). Tokyo: Japanese Forestry Agency, Ministry of Agriculture, Forestry and Fisheries.
- Japanese Forestry Agency. 2015. Annual report on forest and forestry in Japan fiscal year 2014 (Summary). Tokyo: Japanese Forestry Agency, Ministry of Agriculture, Forestry and Fisheries.
- Kahle D, Wickham H. 2013. ggmap: spatial Visualization with ggplot2. R J. 5:144–161.
- Kumazawa Y, Fujita M, Yamasaki A, Koyama K, Ichihara K, Oka M. 2011. Consideration about safety and efficient log transportation by forwarders. J Jpn For Eng Soc. 26:181–186.
- Lindroos O, Wästerlund I. 2013. Utvärdering av skotning med påhängsvagn [Evaluation of forwarding with a trailer]. Rapport 2013:1. Umeå: Swedish University of Agricultural Sciences, Department of Forest Biomaterials and Technology.
- Manner J, Nordfjell T, Lindroos O. 2013. Effects of the number of assortments and log concentration on time consumption for forwarding. Silva Fenn. 47.
- Meyer D, editor. 2011. ASTER global digital elevation model version 2 – summary of validation results.NASA Land Processes Distributed Active Archive Center, online report, 26 pp. Available from: http://www.jspacesystems.or.jp/ersdac/GDEM/ver2Validation/Summary_GDEM2_validation_report_final.pdf.
- Miyata E. 1980. Determining fixed and operating costs of logging equipment. General Technical Report. NC-55. St. Paul, MN: U.S. Dept of Agriculture, Forest Service, North Central Forest Experiment Station.
- Nakahata C, Aruga K, Takei Y, Yamaguchi R, Saito M, Kanetsuki K. 2013. Examining the optimum extraction rate of extracting thinned woods in the Nasunogahara area. J Jpn For Eng Soc. 28:17–28.
- Nakahata C, Aruga K, Uemura R, Saito M, Kanetsuki K. 2014. Examining the optimal method to extract logging residues from small-scale forestry in the nasunogahara area, tochigi prefecture, Japan. Small-Scale For. 13:251–266.
- Nurminen T, Korpunen H, Uusitalo J. 2006. Time consumption analysis of the mechanized cut-to-length harvesting system. Silva Fenn. 40:335–363.
- Oka M. 2007. Present situation of maintenance and repair cost-rates. J For Mech Soc. 639:9–15.
- Oka M, Inoue M, Uemura T, Kobayashi H. 2005. Studies on the rate of maintenance and repair costs of high performance forestry machines. J Jpn For Eng Soc. 20(2):83–94.
- R Studio Team. 2015. RStudio: integrated development for R. Boston, MA: RStudio, Inc.
- Sakai H. 2005. Low cost harvesting for small scale forestry in Japan. Special Issue J Nova Mehanizacija Sumarstva. 26:2.
- Snowdon P. 1991. A ratio estimator for bias correction in logarithmic regressions. Can J For Res. 21:720–724.
- Spinelli R, Magagnotti N. 2010. Performance and cost of a new mini-forwarder for use in thinning operations. J For Res. 15:358–364.
- Tufts RA. 1997. Productivity and cost of the Ponsse 15-series, cut-to-length harvesting system in southern pine plantations. For Prod J. 47:39–46.
- Yoshioka T. 2011. Study on the feasibility of a harvesting, transporting, and chipping system for forest biomass resources in Japan. AGri-Biosci Monogr. 1:1–60.
- Zenkoku-shinrin-kumiai-rengoukai. [全国森林組合連合会] 2012. Text for forest managers: the basics [森林施業プランナーテキスト]. Tokyo: 森林施業プランナー協会.
- Zimbalatti G, Proto A. 2010. Productivity of forwarders in south Italy. Paper presented at: Forest Engineering: Meeting the Needs of the Society and the Environment, Padova, Italy.