The objectives of this study are to clarify the potential use of breathable flexible containers in drying wood chips under varying temperature conditions, to confirm the applicability of the moisture content transition model on those chips, and to determine the properties of parameters in the model. To realize these objectives, transitions of moisture content of wood chips placed inside small-sized breathable containers were measured under the conditions of periodic heating and of an indoor environment at ambient temperatures. The results revealed that periodically heating using waste heat from a chip boiler was effective in reducing the drying time of wood chips. Natural drying using breathable containers at ambient temperatures can be possible, but it typically takes many months. The moisture content transition model that we developed was useful for estimating average moisture content; therefore, the model can be used to predict drying time of wood chips under varying temperature conditions. The coefficient k of the model relates to the average temperature during the measuring periods, while the relationship between k and the distance from breathable surfaces became certain when b was assumed to be a constant.

We investigated compaction in a strip road with the aim of clarifying the influence of mechanized harvesting operations on black soil. A cut-to length (CTL) system, including a wheel-type harvester and forwarder, was used for general and line thinning. The forwarder typically uses more number of machine passes during an operation than that by the harvester. The forwarder passes are especially more in line thinning because the forwarder must return to the yarding when its loading platform is full and return to the previous point along the same strip road after landing. In addition, the strip road was fixed between the tree lines for line thinning and traffic was excessively concentrated. When we measured the degree of compaction on a strip road using a cone penetrometer, we observed relative increase in soil hardness after few machine passes. However, soil softening was observed after additional passes; softening is assumed to be the result of it becoming muddy. Increasing soil hardness was observed from the depths of 15–20 cm; these depths are deeper than those previously reported. When we measured the strip road 2 years after the operation, the road had not recovered from the effects of compaction and the hardness of the muddied soil had increased. It is possible that the soil temporarily became soft; therefore, the influence of mechanized harvesting operations in this type of soil should be evaluated in the long-term and not immediately after operation.

High strength synthetic fiber ropes used in forestry operations are vulnerable to abrasion damage. It is necessary to understand the relationship between damage and remaining rope strength to judge the appropriate timing of replacement. We tested a high strength synthetic fiber rope (10 mm diameter, 12 strands) with eight damage treatments and severities, including a control and a different type of terminal treatment with no damage, each replicated three times. The standard terminal treatment was a simplified eye splicing method in which the rope end was inserted into 10 pairs of picks within the standing rope body without burying it. An alternative terminal treatment buried the end of the rope: it had greater strength than the control although the difference was not significant. No significant differences were observed in residual rope strength between the two grinding discs (hard and soft) used to abrade ropes. However, one deep abrasion treatment with the soft grinding disc resulted in dramatically reduced rope strength. No significant difference was observed between the two- and four-cut strand treatments, or the surface abrasion treatments. The breaking strength of rope as a function of its effective section area was significantly reduced in the deep abrasion treatments, possibly as a result of heat generated during the grinding process.