Harvesting in the boreal forest on soft ground

摘要: The overall aim of the studies underlying this thesis has been to acquire knowledge relating potential methods reducing both amount and severity ground damage caused by forest machinery used in boreal forest. work focused on technical solutions applied forwarders that had reduce such as rutting soil compaction. Additionally, detecting areas a weak bearing capacity, using terrain indices based digital elevation models pre-existing forestry register data. In paper I, it was shown combining data find Rammsonde pressure till soil, 73% measurements correctly classified low or high capacity ground. In II, forwarder with individually steerable wheels described that, compared conventional forwarder, formed shallower ruts when driving straight line land made narrower turning forested arable land. When soft without load, from were shallower. III, simulations showed new Long Track Bogie (LTB), dependent contact area, negotiates obstacles more smoothly than bogie can handle wider ditches. displacement LTB is also smaller turning. In live tests firm ground, mean towing force for 62% higher rolling resistance (paper IV). The results indicate possible harvesting developing machines steering transmission drive systems minimize planning tools predict at stand level. This might allow classification visiting site thus facilitate choice appropriate machines.