Harvester and forwarder productivity and net revenues in patch cutting

ABSTRACT

Patch cutting is beneficial for many ecosystem services, but the effects of the management system on operations have not been analyzed. A two-machine system with harvester and forwarder is often used in mechanized cut-to-length operations. The aim of this study was to analyze differences in harvester and forwarder productivity in final felling and patch cutting, and estimate their effects on net revenues per harvested m3. Harvester time consumption was studied using automatic data collection from the machine computer. The data set comprised approximately 18,150 trees harvested during 48 shifts. Analyzes were based on shift level averages. In the observed interval of 0.30–0.60 m3 average tree volume, patch cutting productivity was 20–15% lower compared to final felling. Forwarding was analyzed in three steps. First, a GIS analysis of terrain transport distance found that patch cutting increased forwarding distance by 29%. Secondly, a time study found that loading and unloading times were 16% greater in patch cutting than in final felling. Thirdly, a theoretical analysis found that total forwarder time consumption was 16% higher in patch cuts than in final felling areas. Operational costs in patch cutting were 18% higher than in final felling, thereby reducing net revenues from harvesting operations by 4%. While operational costs were found to be higher in patch cutting than final felling, they are lower than the costs expected for other continuous cover forest management systems. Investigations of later stages of patch cutting are needed before full conclusions regarding the management system can be drawn.

KEYWORDS:

• StanForD
• time study
• cut-to-length
• logging productivity
• continuous cover forestry
• even-aged forest management
• uneven-aged forest management

Disclosure statement

No potential conflicts of interest are reported by the authors.