The Effect of Wider Logging Trails on Rut Formations in the Harvesting of Peatland Forests

Peatlands are very problematic from the bearing capacity point of view. Therefore, logging activities on peatlands in Finland are mainly carried out during the coldest weeks in winter time. More intensive utilisation of peatland forests requires logging activities to be increasingly carried out during unfrozen conditions. Multiple passages of a harvester and a loaded forwarder used for the transportation of timber cause deep ruts on the forest floor. Wider logging trails have been presented as an interesting approach to increasing the number of forwarder passages along a single logging trail. It might be advantageous not to follow the same ruts on each pass but to choose a new parallel route, so that new ruts are formed alongside the previous ones. The study aimed at investigating whether it is beneficial to use wide trails in reducing rutting in forests growing on drained peatland. Field studies were conducted on a drained peatland in Alkkia experimental forest, located in Karvia in Western Finland. In the driving test, a forwarder was driven in the same forest site on logging trails with widths of 4.5 m, 6 m and 10 m. The results indicate that wider logging trails provide the forwarder driver with opportunities to reduce rutting in peatland forests.