| 摘要 |
A method of standing-stem log harvesting including the steps of preparing a tree for harvesting and then harvesting the same directly from the stump. A tree is prepared for harvesting by topping the tree, cutting the tree part way through the trunk near ground level with two cuts lying in generally the same plane to leave holding wood between the resulting two generally parallel cut edges, and driving support wedges or the like into both said cuts to stabilize the tree trunk. The holding wood and the wedges maintain the trunk stable and upright until it is harvested, but the holding wood is readily frangible in response to a generally horizontal pivoting force applied to the trunk near the top thereof in a direction generally perpendicular to the cut edges. For harvesting, the prepared tree is gripped near the top thereof, and a generally horizontal force is applied to the trunk at the point of gripping in a direction generally perpendicular to the cut edges, thereby breaking the holding wood. The severed log is then hoisted and removed to a selected drop site. Apparatus for practising the standing-stem log harvesting method includes a helicopter and a grapple suspended generally under the center of gravity of the helicopter for gripping and hoisting the tree trunk.
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