The effect of labor work contract on felling operation and wood losses

The objectives of study were to compare different types of wood loss including breakage, split, slab, and high stump and also to investigate cut components such as, height and depth of undercut and back cut, notch, and width of hinge wood between the two groups of workers. Parcels no. 138 and 139 in Asalem Nav series 1 were chosen as the study area. 150 felled trees by workers paid by piece and day work method were selected randomly. The mean stump loss between the two groups was compared by Independent- Sample T- test and the comparison between the size of each components of felling and the standard felling was made by Paired Sample T-test. There was a significant difference between felling values in different groups compared with standard values except the depth of back cut in the second group (33.41 cm) and the width of hinge wood in the first group (6.78 cm). The average high stump loss for the four groups was 0.035, 0.0355, 0.0498, and 0.0438 m3, respectively. The average loss per felled tree among the four groups was 0.2915, 0.2286, 0.3775 and 0.4637 m3, respectively. There was a significant difference between mean value losses of wood in the four groups; the day work paid group had fewer losses compared the piece work paid group. The largest volume of loss in all groups belonged to breakage damage. Regarding the price of different products fabricated from the wood cut, results showed that the greatest decrease in price belonged to the groups paid by piece work contract.