J. For. Sci., 2023, 69(7):317-323 | DOI: 10.17221/44/2023-JFS
A pilot study of continuous cover forestry in boreal forests: Do remaining trees affect forwarder productivity?Short Communication
- 1 Skogforsk, Uppsala, Sweden
- 2 School of Forest Management, Swedish University of Agricultural Sciences, Skinnskatteberg, Sweden
According to the literature, forwarding productivity depends chiefly on log concentration, the number of assortments, mean log volume, load-size, slope, and extraction distance. However, there is not much scientific knowledge available on forwarding in continuous cover forestry (CCF) in boreal forests, nor whether the presence of remaining trees actually affects forwarding productivity. Thus, the objective of our study was to isolate the effect of remaining trees (i.e. stand density) on forwarding productivity during CCF, specifically selection cutting. The results showed that productivity was explained mainly by the log concentration, while other factors had at most minor effects. Most importantly, stand density did not significantly affect forwarding productivity, ceteris paribus. Thus, we conclude that remaining trees do not affect forwarding productivity in boreal forests. Although the study results from this CCF operation must only be cautiously applied to even-aged forestry, our results raise a general question: do we need separate productivity models for thinning and clearcut operations in boreal forests if remaining trees (stand density) do not affect forwarding productivity? Because of the small dataset, we consider our paper to be a pilot study whose findings need to be verified by studies based on larger datasets including several operators and stands.
Keywords: cut-to-length logging; time study; forest operation; partial cutting; single-tree selection; extraction
Received: April 20, 2023; Revised: May 28, 2023; Accepted: May 30, 2023; Published: July 26, 2023 Show citation
References
- Barrett T.J. (2011): Computations using analysis of covariance. Wiley Interdisciplinary Reviews: Computational Statistics, 3: 260-268.
Go to original source...
- Berg S. (1992): Terrain Classification System for Forestry Work. Stockholm, Forest Operations Institute: 28.
- Berg S., Ersson B.T., Manner J. (2019): Distance driven and driving speed when forwarding during final felling in Central Sweden. Journal of Forest Science, 65: 183-194.
Go to original source...
- Biometria (2020): Measurement of roundwood stacks. Swedish regulations for timber measurement. Version 2020-10-01. Available at: https://www.biometria.se/media/a5xchk3j/measurement-of-roundwood-stacks-2020-10-01.pdf
- Cadei A., Mologni O., Röser D., Cavalli R., Grigolato S. (2020): Forwarder productivity in salvage logging operations in difficult terrain. Forests, 11: 341.
Go to original source...
- Eriksson M., Lindroos O. (2014): Productivity of harvesters and forwarders in CTL operations in northern Sweden based on large follow-up datasets. International Journal of Forest Engineering, 25: 179-200.
Go to original source...
- Grönlund Ö., Eliasson L. (2019): Birch shelterwood removal - Harvester and forwarder time consumption, damage to understory spruce and net revenues. International Journal of Forest Engineering, 30: 26-34.
Go to original source...
- Hansson L.J., Forsmark V., Flisberg P., Rönnqvist M., Mörk A., Jönsson P. (2022): A decision support tool for forwarding operations with sequence-dependent loading. Canadian Journal of Forest Research, 52: 1513-1526.
Go to original source...
- Hildt E., Leszczuk A., Mac Donagh P., Schlichter T. (2020): Time consumption analysis of forwarder activities in thinning. Croatian Journal of Forest Engineering, 41: 13-24.
Go to original source...
- Johnson T.R. (2016): Violation of the homogeneity of regression slopes assumption in ANCOVA for two-group pre-post designs: Tutorial on a modified Johnson-Neyman procedure. The Quantitative Methods for Psychology, 12: 253-263.
Go to original source...
- Manner J., Nordfjell T., Lindroos O. (2013): Effects of the number of assortments and log concentration on time consumption for forwarding. Silva Fennica, 47: 1030.
Go to original source...
- Nurminen T., Korpunen H., Uusitalo J. (2006): Time consumption analysis of the mechanized cut-to-length harvesting system. Silva Fennica, 40: 335-363.
Go to original source...
- Proto A.R., Macrì G., Visser R., Harrill H., Russo D., Zimbalatti G. (2018): Factors affecting forwarder productivity. European Journal of Forest Research, 137: 143-151.
Go to original source...
- Strandgard M., Mitchell R., Acuna M. (2017): Time consumption and productivity of a forwarder operating on a slope in a cut-to-length harvest system in a Pinus radiata D. Don pine plantation. Journal of Forest Science, 63: 324-330.
Go to original source...
- Tiernan D., Zeleke G., Owende P.M.O., Kanali C.L., Lyons J., Ward S.M. (2004): Effect of working conditions on forwarder productivity in cut-to-length timber harvesting on sensitive forest sites in Ireland. Biosystems Engineering, 87: 167-177.
Go to original source...
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