The Impact of Season on Productivity and Time Consumption in Timber Harvesting from Young Alder Stands in Lowland Poland

Abstract

The purpose of this study was to establish the impact of season on productivity, labour consumption, and working time structure during timber harvesting from young alder stands (Alnus glutinosa Gaertn.). An early thinning process was performed in summer and winter in pure alder stands (38 and 40 years old) in the Płaska Forest Division (NE Poland). The felling and processing operations were performed by experienced loggers using the cut-to-length (CTL) system, and forwarding with manual loading and unloading involved the use of a Zetor 7045 (65 HP) farming tractor and trailer. In both summer and winter, the loggers spent most of their labour time on felling trees (approx. 23%) and bucking (approx. 36%). Assistant loggers spent most of their time stacking logs (49.2% in summer and 58% in winter). The most time-consuming activities in forwarding were loading, unloading, and transportation. The average time consumption of tree felling and processing amounted to 0.36 ± 0.11 h/m3; that of forwarding was lower, at 0.24 ± 0.07 h/m3. No statistically significant differences in the labour consumption of tree felling were identified between winter and summer (p = 0.863). For forwarding, labour consumption was significantly higher in winter (0.28 h/m3) than in summer (0.19 h/m3, p = 0.001). Average productivity was 3.02 ± 1.09 m3/h for tree felling and 4.76 ± 1.80 m3/h for forwarding. The productivity of felling was similar in winter (2.83 m3/h) and in summer (3.22 m3/h). For forwarding, productivity was significantly higher in summer (5.70 m3/h) than in winter (3.81 m3/h, p < 0.01).

The Impact of Weather and Slope Conditions on the Productivity, Cost, and GHG Emissions of a Ground-Based Harvesting Operation in Mountain Hardwoods

“…Although the current study confirms that both slope gradients and weather conditions affected the felling productivity and the cost, this is not always straightforwardly the case. This result is not consistent with the findings of Grzywi ński et al [18], in which felling productivity rates were similar in winter (snowy) and summer (sunny) in ground-based harvesting operations.…”

“…The longer log processing time can be attributed to the large volume of hardwood stems, the variable topographic conditions, and the higher density of understory vegetation. Similar patterns were noted by Mousavi [34] and Grzywi ński et al [18], who found that 58% of the labor time was spent during felling and processing in a ground-based harvesting operation.…”

“…Overall, numerous studies have addressed the ground-based skidding system, mainly focused either on felling or log extraction, worldwide, which shows the importance of the subject (for example, see [10,[13][14][15][16][17][18][19]). A large body of literature on this subject emphasizes the physical characteristics of harvesting operations (e.g., load volume per cycle, skidding distance, and tree diameter) as major factors influencing the performance of the ground-based operation [17,20].…”

“…In addition to the stand, geophysical, and logistical factors, a very few recent studies have considered the significance of variable weather conditions on the performance of a ground-based harvesting operation. Grzywi ński et al (2020) found that the winter felling practice took about 13% longer compared with the summer felling practice [18].…”

Estimation of productivity and cost of small-size fully-mechanized cut-to-length systems

“…This is mainly necessary for calculating cost calculations or employee salaries. Detailed time studies allow to evaluate the performance of forest machine operators [1], to identify problems associated with work in night shifts [2], to develop productivity forecasting models, to find the most suitable logging machines for specific types of felling and work conditions [3], [4], and to compare seasonal variations of productivity [5].…”