ABSTRACT

In many northern forests, the preferred time of harvesting is when the ground is frozen. Logging activities on frozen ground reduce the cost of forest operations by allowing heavier loads on temporary roads and makes crossing wetlands feasible. Increased winter temperature and more frequent winter thaws decrease the period of frozen ground conditions. In order to adapt to shorter periods of frozen logging season, forest companies might have to access frozen harvesting sites in the non-frozen season. In this study, we examined the cost of temporary forest road construction in terms of switching logging activities from frozen to non-frozen conditions. The objectives were to estimate the costs of non-frozen temporary roads for four harvesting units with different difficulty of access. We also analyzed construction costs for both frozen and non-frozen access under possible different wetter and drier scenarios. The results show that the average cost of temporary road construction increased from $1,200 km⁻¹ or $0.30 m⁻³ in frozen conditions to $5,962 km⁻¹ or $2.14 m⁻³ in non-frozen conditions. Under the extreme wet scenarios, the cost of non-frozen roading ($ m⁻³) of the unit with the most difficult access was up to 14.6 times more than frozen road construction. If the soil dried faster than the base case scenario, cost increases of non-frozen road construction ($ km⁻¹) were expected to be between 2.3 times and 8.6 times more than the frozen road construction cost, depending upon the difficulty of accessing the unit.

摘要

在许多北方森林中，收获的首选时间是地面结冰时。在冻土上进行伐木活动可以让临时道路承受更大的负荷，从而降低森林经营成本，并使穿越湿地变得可行。冬季温度升高和更频繁的冬季解冻减少了冻土条件的时间。为了适应较短的冰冻采伐季节，林业公司可能不得不在非冰冻季节进入冰冻采伐场。在这项研究中，我们研究了临时林道建设在将采伐活动从冻结条件转换为非冻结条件方面的成本。目标是为四个不同难度的采伐单位估算非冻结临时道路的成本。我们还分析了在可能的不同潮湿和干燥情况下冻结和非冻结通道的建设成本。结果表明，临时道路建设的平均成本从 $1,200 km 增加^-1或 $0.30 m ^-3在冻结条件下到 $5,962 km ^-1或 $2.14 m ^-3在非冻结条件下。在极端潮湿的情况下，最难进入的单元的非冻结道路建设成本（$ m ^-3）是冻结道路建设的14.6倍。如果土壤干得比基本情况更快，则非冻结道路建设的成本增加（$ km ^-1）预计将是冻结道路建设成本的 2.3 到 8.6 倍，具体取决于进入道路的难度。单元。