Energy wood logging from early thinnings by harwarder method.

摘要

During the last decade, harwarders have been developed for both industrial roundwood and energy wood harvesting. This article looks into the productivity results obtained by a conventional forwarder equipped with the Moipu 400 E energy wood harwarder grip in thinning a young stand in Finland. Productivity functions for the harwarder logging were formulated by applying a regression analysis in which the harvesting conditions (tree volume, cutting removal, forwarding distance etc.) were independent variables. The logging productivity of small trees with branches using the harwarder method, was 3.3 m3/E0-h (effective working hour), when the tree volume was 25 dm3, accumulation of energy wood 50 m3 ha-1, load volume 6.2 m3 and forwarding distance 250 m. Felling and bunching represented 45% of the energy wood harwarders effective working time. Making a strip road took 18% of the total time consumption and loading of felled trees 17%. Time consumption of forwarding was 6% loaded and 5% unloaded. Moving during cutting and loading and unloading at landing represented both 5% of the effective working time..