Equations to estimate processing and forwarding costs, while considering log size: clear-cutting operations in Nasunogahara, Tochigi prefecture, Japan

ABSTRACT

This study develops equations by which one can estimate processing and forwarding costs for clear-cutting operations, while considering log size and assuming moderately and gently sloping sites. Processing cycle times were estimated by using the average delimbing and bucking times related to average log volume and piling time related to the number of logs extracted from the stem. Forwarding cycle times were estimated by using the forwarding distance, the out-hauling and in-hauling travel velocities, and the loading and unloading time related to the number of loaded logs. The forwarding volume was estimated by using the relationship between the average log volume and the number of logs loaded on the forwarder. Differences in processing costs between 0.02 and 0.20 m³/log worked out to around USD 10.00/m³, whereas differences in forwarding costs between 0.02 and 0.20 m³/log worked out to around USD 4.00 and USD 7.00/m³ for thinning and clear-cutting operations, respectively. Finally, operational system costs were estimated: differences in operational system costs with the extraction of small-sized logs (and while not considering log size) between maximizing revenues and profits were USD 9.08, USD 9.05, and USD 9.36/m³ at Site A, Site B, and thinning operations, respectively. However, those costs ranged from USD 36.65 to USD 87.65/m³ for Site A, from USD 28.75 to USD 70.21/m³ for Site B, and from USD 27.71 to USD 70.81/m³ for thinning operations. Thus, costs should be estimated while duly considering log size.

KEYWORDS:

• Clear-cutting
• commercial thinning
• cycle time
• log size
• processing and forwarding cost

Acknowledgments

We are grateful to the Nasu-machi Forest Owners’ Co-o perative for their cooperation during our research.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the JSPS KAKENHI: [Grant Numbers 15H04508 and 16KK0168].