Production rates and costs of whole-tree, tree-length, and log-length skyline thinning

Production rates and costs were determined for harvesting smallwood by different methods of skyline yarding: whole-tree (yarding with limbs and tops), tree-length (bucking done on the landing), and log-length (limbing, topping, and bucking done on the slope). A rubber-tired skidder was used to swing and sort the variously cut trees from the landing to a site on the haul road for further processing. The production rates for the felling and yarding cycles of each logging method were predicted from regression equations. Felling production rates were 3.60 cubic m. per hour for log length, 4.70 cubic m. per hour for tree length, and 6.17 cubic m. per hour for whole-tree. Yarding production rates were 5.52 cubic m. per hour for log length and 5.83 cubic m. per hour for both tree-length and whole tree. Cost analysis indicated that, where feasible, cold decking (stacking in front of the yarder) of log-length material is the most cost-effective method because it eliminates the need for a skidder to swing the logs. However, where cold decking is not feasible and a skidder is used, the whole-tree method is the next least expensive: cost per unit is 12% less than log-length yarding. 9 references.