FERIC studied manual and mechanized felling operations with extraction by cable skidder within the Turkey Lakes Watershed in central Ontario. The study compared manual and mechanized clearcutting and partial-cutting operations (shelterwood and selection cuts) and found that felling and extraction productivities were greatest in clearcutting. However, site disturbance depended as much on how the operation was conducted as on the harvesting system used. From the perspective of riparian-zone management, each cut intensity and harvest system offers different advantages with respect to slash distribution and mineral-soil exposure, and their respective merits must be considered in light of the silvicultural objectives.
Pacific Forest Products Limited began commercially thinning Douglas-fir dominated second-growth forest on southeastern Vancouver Island with mechanized shortwood systems in 1992. In the summer of 1994, FERIC monitored a thinning operation near Cowichan Lake to determine productivities, costs and impacts to sites and residual stands. The thinning treatment was carried out with a Timberjack 1270 harvester and a Timberjack 910 forwarder.
In Canadian boreal forests, harvesting with protection of advance regeneration requires the creation of an intensively used network of skid trails. In this context, the effects of repeated skidder passes on soils were studied in terms of rut depth, the amount of displaced material in the trails, and soil bulks density. Two types of soil were studied: sands and clays. The factors that helped to explain the observed amount of soil disturbance were the number of skidder passes, the amount of wheel slippage, soil density, the soil's penetration resistance, and the soil's shear resistance. The results of the study indicated that the effects of skidder traffic on soil properties stabilized after a few skidder passes on sands, whereas the effects on clay soils continued to increase with an increasing number of skidder passes.
Les porteurs à roues sont utilisés courament dans les opérations de récolte en forêt privée dans l'est du Canada, particulièrement dans les provinces de l'Atlantique. Cette fiche technique présente les résultats de plusieurs études de production de courte durée sur le porteur Timberjack 230 8-tonnes, dans des opérations de récolte réalisées par des entrepreneurs en Nouvelle-Écosse. Les porteurs travaillaient dans des conditions variées de peuplement et de terrain, et étaient équipés de pneus standard (24.5x32) et de pneus larges (66/43.00x26).
During the fall of 1999, the Forest Engineering Reasearch Institute of Canada (FERIC) performed a short-term study on a Trans-Gesco TG 88 clambunk skidder working near Terrace in northwestern British Columbia. The study provided information about the skidder's productivity and cost. Production functions were derived to predict skidder performance over a range of operating conditions.
This report presents the results of a 1997 study of clearcutting with the protection of small merchantable stems (stems 10 and 12 cm in DBH). FERIC compared three full-tree work methods and a cut-to-length method that included the protection of small stems. A conventional clearcut with protection of regeneration and soils was assessed with both systems to serve as a basis for comparison. Data on the levels of productivity, protection of regeneration, and soil disturbance are reported.
FERIC conducted a synoptic survey of 102 landslides on the Queen Charlotte Islands, 97 of which originated within logged areas, to provide forest engineering input into the interpretation of probable causes and possible preventative measures. The principle factors in road-related landslides appeared to be overloading of steep slopes with fill or sidecast material and inadequate control of road drainage. Specific causes for landslides that initiated within clearcuts but away from roads could rarely be identified. However, the yarding process probably accelerated landslide activity at critical points where poor deflection generated severe yarding disturbance on sensitive slopes.
If not done properly, forwarding operations present a risk of damage to forest soils, which can impact water quality and future tree growth. Such damage may include compaction, rutting, erosion and nutrient loss. This guide was created to help forwarder operators choose the best working techniques to avoid damaging forest soils during harvesting operations. It provides good practices, guidelines on operating when soil strength is reduced, and tips on working around wetlands and during winter operations.