Economic feasibility of timber harvesting in lowlands
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In: Czupy, Imre, ed. Exceeding the vision: forest mechanisation of the future. Proceedings of the 52nd International Symposium on Forestry Mechanization. Sopron, Hungary: University of Sopron Press: 379-393.
Northern white-cedar (Thuja occidentalis L.) is an important commercial tree species in the New England and Great Lakes regions of the USA and adjacent Canada, yet cedar-dominated stands are comparatively less harvested. This is mainly attributed to the operational challenges associated with fragile and poorly drained soils in lowlands where the species is commonly found. In terms of forest operations, such conditions can pose safety hazards for both crew and machines and harvesting might not be economically viable. The objectives of this study were to 1) estimate cost and productivity of timber harvesting operations in a sensitive-soil stand relative to those of an operation on sturdy ground, 2) understand the effects of stand variables on productivity as expressed by delay-free cycle (DFC) times. The study was conducted in Maine, USA using cut-to-length (CTL) harvesting during the winter of 2019. Stands selected for the treatments were lowland cedar-dominated (>80% cedar, with fragile soils) and non-cedardominated (~10% cedar, with a sturdy soil profile). DFC times and predictor variables were recorded for the harvester and forwarder using detailed time-motion study techniques. Harvested wood timber volume was estimated from scaling data and scale tickets. Machine rate calculations to determine hourly production cost were performed utilizing information from the forest management company. The cost of the operation was found to be higher for the cedar stand (USD 31.93 m-3) than the adjacent non-cedar stand (USD 24.27 m-3). Cost of extraction was reduced by 34–41% when the landing was shifted to stand boundary. Apportioning methods showed that the cost of felling and processing cedar (USD 6.35 m-3) was higher than hardwoods (USD 6.09 m-3) and other softwoods (USD 5.66 m-3). Sensitivity analysis showed that increases in predictor variables such as butt-end diameter, distance between the trees, and number of cuts per cycle increased the DFC time of the harvester. In the case of the forwarder, length and diameter of the log were inversely proportional to the DFC time, whereas an increase in forwarding distance and number of pieces increased the DFC time. Though few, if any direct effects of soils were found on winter harvesting productivity and costs, tree species composition was an influential factor and is itself related to soils. This work will allow foresters and timberland managers to make more informed decisions regarding cost-effective and sustainable forest management in lowlands.
Keywordscedar; cut-to-length; forest operations; sensitivity analysis; winter harvest
George, Alex Kunnathu; Kizha, Anil Raj; Kenefic, Laura. 2019. Economic feasibility of timber harvesting in lowlands. In: Czupy, Imre, ed. Exceeding the vision: forest mechanisation of the future. Proceedings of the 52nd International Symposium on Forestry Mechanization. Sopron, Hungary: University of Sopron Press: 379-393.