Speaker
Description
Interest in continuous cover forestry (CCF) is increasing across the Nordic countries, driven by forest owner preferences, certification requirements, and policy developments. Compared with rotation forest management, CCF typically results in lower harvested volumes per hectare (m3/ha) and smaller total removals per tract (m3/tract). Combined with a long-term trend towards smaller tract sizes, these conditions challenge the cost-efficiency of the conventional Nordic cut-to-length harvesting system comprising a harvester and a forwarder (two-machine system; TMS). In particular, fixed costs such as machine relocation are spread over smaller volumes, increasing harvesting costs per cubic metre.
We examine the potential of single-machine systems (SMS) to improve cost-efficiency and maintain a high level of mechanization under Nordic CCF conditions. SMS perform cutting and extraction with a single machine, thereby incurring only one machine relocation cost per tract instead of two. As a result, the relative competitiveness of SMS increases as tract size, harvested volume per hectare, and extraction distance decrease – conditions that are becoming increasingly common with the expansion of CCF and forest road networks in the Nordics.
SMS are commonly categorized as either harwarders or dual machines. However, the only commercially available SMS in the Nordics today are small-sized dual machines (SmallSMS) designed for harvesting small-diameter trees. These machines cannot fell and process large trees, which is a drawback because CCF harvesting often involves thinning from above and cutting large trees (>1 m³ per stem). Consequently, current SmallSMS are poorly suited for widespread application in Nordic boreal CCF stands.
Therefore, we explore the need for large single-machine systems (LargeSMS) capable of handling large trees while minimizing damage to the remaining stand. By combining lower relocation costs with sufficient harvesting capacity, LargeSMS have the potential to outperform TMS on low-removal tracts, improve machine utilization, and reduce total harvesting costs. Maintaining mechanized harvesting under these conditions is also important from a safety perspective because in the Nordics, motor-manual harvesting is largely unacceptable due to substantially high accident and fatality rates.
Using key productivity- and costing factors including removal per hectare, tract size, assortments’ volume distributions, extraction distance, and relocation costs, we simulate TMS and LargeSMS concepts (harwarders, dual machines, etc.) across a range of realistic Nordic CCF conditions. The results will identify economic and operational break-even points at which LargeSMS are more competitive alternatives in CCF than TMS. Given that CCF continues to expand in Nordic forestry, the economic disadvantages of TMS on low-removal tracts are most likely to become more pronounced. At the same time, growing adoption of CCF suggests that market conditions may now support renewed development and commercialization of LargeSMS. Therefore, we postulate that LargeSMS represent a promising pathway towards cost-efficient and safe harvesting in Nordic CCF.
| Keywords | logging; harwarder; dual machine |
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