Evaluation of Productivity and Cost Analysis on a Combined Logging System

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The paper entitled "Evaluation of productivity and cost analysis on a combined logging system" is a very interesting work, because it deals with a significant topic for the area of forest use and deals with a work system that is not usual for the conditions of the Balkans.

In order for the results of the research to be clearer, it is necessary to make certain corrections and additions to the paper before its publication.

1. Figure 1 is missing a scale ruler or at least a map scale.

2. Looking at the values on the isohypses, i.e. the height differences between the starting and ending points (dH=135, 225, 220 and 165 m) and the indicated average line length of 150 m, one gets the impression of significantly greater longitudinal slopes than those stated in the paper (25, 34, 34, and 31%) or much larger line lengths. It is necessary to match the map with the text.

3. I believe that it would be useful to specify the longitudinal slopes of the tractor roads, considering that the longitudinal slope of the road in the 3rd and 4th position seems extremely large (over 35%), which can also affect the efficiency of work.

4. In Table 2, the minimum required power of the tractor for the operation of the forest cable yarder is listed, but it would be useful to also specify the power of the Belarus 1221.3 tractor.

5. There is a problem with Figure 4...

6. The comparison with the use of clambunk skidder in eucalyptus stands, where the working conditions are completely different (flat terrain, clean felling...), has no special significance for these studies, I even think that they can lead the reader to wrong conclusions.

7. The methodology of Ackerman et al was used when calculating the operating costs of the mentioned assets. 2014, but it is not clearly shown how the input costs were determined. Also, it is not clear whether the costs of the Belarus tractor or just the Valentini cable car were also taken. Were the purchase prices of new or used equipment taken into account and how much were the approximate purchase prices of the machines.

8. In the Results chapter, the authors compare the unit costs of extracting wood assortments with the unit costs arrived at by other researchers. However, the problem is the fact that current unit costs are compared with unit costs from 2006 and 2010, without taking into account the impact of inflation. Even the comparison with unit costs in 2021 can be questioned.

Author Response

Thanks for your comments. All comments have been reviewed.

Comments 1-2. We replaced the map with a new one with a scale ruler (Figure 1) and added in Section 2.2 in the text the lengths of the corridors, as well as the slopes in degrees and percentages.

Comment 3. We added the following sentence in Section 2.2: The longitudinal slope of the skidding road in the section from Corridor 4 to midway between Corridor 2 and Corridor 1 of the Tower Yarder averages 11° (19%) uphill, while in about twice as long the section to the landing is 3° (5 %), also uphill, which, however, is not much slope resistance to the operation of the dedicated clambunk skidder.

Comment 4. We added the rated power of the engine of Belarus 1221.3 farm tractor in Table 2.

Comment 5. The figure 4 was reloaded correctly.

Comment 6. We removed the clambunk skidder comparison in the eucalyptus stand as You suggested.

Comment 7. We added the purchase costs of the studied machines in Table 6.

Comment 8. We changed the comparison of the extraction cost of wood assortments, using other recent works.

Sincerely,

Authors

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The topic falls within the theme of the special issue. The novelty and the originality degree is average. Literature in the field abounds in articles that approach the topic of productivity and costs for various wood harvesting systems. In this paper, a solution based on the use of two classical types of equipment - a tractor-mounted tower yarder and a clambunk skidder – is presented. The work phases of a work cycle is correctly established for both pieces of equipment, though.  However, a working time structure is not presented. Important time elements are not taken into account e.g.: non-workplace time, non-work time, supportive work time, preparatory time, service time, ancillary work time, relocation time, planning time, maintenance time, refuel time and delays. All these time elements represent time consumed by activities carried out in a work shift. When all of these elements are known, their optimization can be established in order to reduce unproductive time and delays (The causes of delays, be they operational or mechanical, are either not mentioned or just vaguely mentioned. Also, there is no mention of the ways in which these can be avoided or reduced.)

 Statistical processing and interpretation of data and results are based on the use of regression but it is not mentioned if data is normally distributed (what test / tests have been used for checking the normal distribution).  

All comments were highlighted in the text (see attachment).

Comments for author File: Comments.pdf

Author Response

Thanks for your comments. All comments found along the text in the supplementary file, have been reviewed. We considered all nonproductive elementary times as delay times (SMH) and provided a net time rating (PMH) to make a parameter comparable to other studies. We added text about checking data for a normal distribution: The normal distribution of experimental data values was established using the Kolmogorov–Smirnov (K–S test) and Shapiro–Wilk tests.

Sincerely,

Authors

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

I recommend to reload figure 4. The explanations of the legend in figures 6b and 6c are missing.

A little hard to follow the explanations for figures 6a, 6b and 6c.

 

Author Response

Thanks for your comments. We have reloaded Figure 4. The legend of figures 6b and 6c have been fixed and we have arranged the text for Figures 6a, 6b and 6c.

Sincerely,

Authors

Author Response File: Author Response.pdf

Reviewer 4 Report

Comments and Suggestions for Authors

Specific comments:

L. 12-25. Abstract needs rewriting - results should be included.
L.60. Melemez et al. [16] - according to the References it should be [18].
L. 92 Should be [29] instead of Dos Santos et al. 2013.
L. 107, 120. Numbering of figures should follow the order in which they appear in the text.
L. 132 [31, 32, 3, 33, 34] - ascending.
L. 189. Fig. 1 - it seems that it should be Fig. 4.
L. 215. Fig. 4 needs improvement.
L. 283. Fig. 5 is not cited in the text.
L. 325. Figs. 6a and b need an addition to the legend.
L. 355. Table 6 is not cited in the text.

Author Response

Thanks for your comments. We made the changes you suggested.

L.12-25. We added the results in the abstract.

L.60. The correct number of references is [18].

L.92. For Dos Santos et al. 2013 the correct number of references is [29].

L.107,120. We have corrected the numbering of the figures based on the text.

L.132. We changed the references in brackets in ascending order.

L189. The correct number is Fig. 4.

L.215. Figure 4 was reloaded correctly.

L.283. Figure 5 was cited in the text.

L.325. The legend has been added to figures 6a and b.

L.355. Table 6 was cited in the text.

Sincerely,

Authors

Author Response File: Author Response.pdf

Reviewer 5 Report

Comments and Suggestions for Authors

Thank you for the opportunity to review your paper, “Evaluation of productivity and cost analysis on a combined logging system.” as submitted to Forests Journal (MDPI).

 

This paper presents an effective and concise approach in a very important subject in the field of Evaluation of productivity and cost analysis on a combined logging system. However, in the introduction is missing the discussion how the resilience of the buildings in the recommended approach can be affected (see below)

 

1)Tampekis, S., Kantartzis, A., Arabatzis, G., Sakellariou, S., Kolkos, G., & Malesios, C. (2024). Conceptualizing Forest Operations Planning and Management Using Principles of Functional Complex Systems Science to Increase the Forest’s Ability to Withstand Climate Change. Land, 13(2), 217.

 

2) Talebi, M., Majnounian, B., Abdi, E., & Omid, M. (2020). Preparing of capability map for road construction using artificial neural network and GIS (case study: Arasbaran area). Forest Research and Development, 6(1), 121-134.

 

3) Putz, F.E.; Sist, P.; Fredericksen, T.; Dykstra, D. Reduced-impact logging: Challenges and opportunities. For. Ecol. Manag. 2008, 256, 1427–1433. 

 

The abstract emphasizes in the scope of the paper and at the same time presents the theoretical framework. The introduction is relevant and covers all the aspects of the recommended theme. Also, the bibliography is updated and theory based.

 

The results and the discussion are well presented.

 

Finally, the discussion is very helpful and shows the effectiveness of the suggested framework. 

Comments on the Quality of English Language

Thank you for the opportunity to review your paper, “Evaluation of productivity and cost analysis on a combined logging system.” as submitted to Forests Journal (MDPI).

 

This paper presents an effective and concise approach in a very important subject in the field of Evaluation of productivity and cost analysis on a combined logging system. However, in the introduction is missing the discussion how the resilience of the buildings in the recommended approach can be affected (see below)

 

1)Tampekis, S., Kantartzis, A., Arabatzis, G., Sakellariou, S., Kolkos, G., & Malesios, C. (2024). Conceptualizing Forest Operations Planning and Management Using Principles of Functional Complex Systems Science to Increase the Forest’s Ability to Withstand Climate Change. Land, 13(2), 217.

 

2) Talebi, M., Majnounian, B., Abdi, E., & Omid, M. (2020). Preparing of capability map for road construction using artificial neural network and GIS (case study: Arasbaran area). Forest Research and Development, 6(1), 121-134.

 

3) Putz, F.E.; Sist, P.; Fredericksen, T.; Dykstra, D. Reduced-impact logging: Challenges and opportunities. For. Ecol. Manag. 2008, 256, 1427–1433. 

 

The abstract emphasizes in the scope of the paper and at the same time presents the theoretical framework. The introduction is relevant and covers all the aspects of the recommended theme. Also, the bibliography is updated and theory based.

 

The results and the discussion are well presented.

 

Finally, the discussion is very helpful and shows the effectiveness of the suggested framework. 

Author Response

Thanks for your comments. We have added a sentence about the resilience of the buildings in the introduction.

Sincerely,

Authors

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

The results are appropriately stated and commented. The reference section contains relevant bibliography for the topic approached in the paper. In the introduction these references are used as background for the presentation and justification of the topic approached and later on they are used to support the results obtained and the discussions.

 Following the changes made by authors, the paper has significantly improved and it deserves publication.