Financial comparison of strip road alternatives in the harvesting of pine stands on drained peatlands.

摘要

The effects of different strip road alternatives on harvesting conditions, machine productivity and harvesting costs, stand development, and net income for the forest owner during the rotation period were compared in Scots pine (Pinus sylvestris) stands on a drained peatland in southern Ostrobothnia, western Finland. The study material consisted of 12 stands, in which the average distance between ditches was 40 metres. Three different marking alternatives were studied. In the first alternative, the strip roads were located 10 metres from the ditches, and the distance between the strip roads was 20 metres. Both harvester and forwarder operated on the strip roads. In the second alternative, the strip roads for forwarder were on the ditches, and a small harvester operated on strip roads and on two narrow cutting strips between the ditches. These two alternatives were compared with the third, theoretical alternative, in which there were no actual strip roads. The alternative markings resulted in different thinning removals as well as different growing stocks. The growing stocks were entered into the MOTTI stand simulator and the growth and yield for the rest of the rotation were simulated. Harvesting costs (including both cutting and forwarding) were calculated for Markings 1 and 2. The ditch network maintenance costs in the stands, which were estimated to be in need of ditch network maintenance were included in the financial analyses. The Marking methods were very similar with respect to growth and yield during the rotation. However, the harvesting schedules, i.e. the number and timing of the thinnings, differed slightly between the marking methods. The average first thinning harvesting costs in Marking 1 were 4% lower than in Marking 2. The difference was partly caused by the larger average stem size in Marking 1, and partly by the lower productivity of cutting when using the cutting strip method. However, the alternatives did not differ statistically significantly from each other. The results for the strip road alternatives were very similar with respect to financial performance. This result allows us to plan strip roads that are more specific to the site conditions without losing too much profitability. If there is a need for ditch network maintenance, Marking 2 is recommended. A considerable proportion of the first thinning removal comes from the strip roads, and this removal has an important effect on the harvesting costs. In this study thinning harvesters were used in the thinnings. However, medium-sized harvesters or harvester-forwarders can also be used in Marking 1. Thus, peatland harvesting can also mainly be carried out with the machinery used on mineral soil sites..