Evaluation of Salvage Logging Productivity and Costs in the Sensitive Forests of Bulgaria

Round 1

Reviewer 1 Report

This is an interesting manuscript but the following points have to be addressed:

L23: "decreased to" instead of “has decreased at”

L24: Under the prevailing conditions

L26 of the machine

L27: The gross costs of uphill yarding in the studied dominance order was as follows: change to “The gross costs of uphill yarding in the studied dominance order was as follows”: I it necessary? The calculation of groos costs of uphill yarding has shown that…

I would suggest to reconcider the keywords.

L58: “of naturalistic interest” can be avoided. Sensitive areas is more than enough.

L71: If you insist on using both words (limit/restrict) explain the thin difference between them in a longer or a new sentence. Another option could be “regulate”.

L91: .. by the use of..

While very informative, I would suggest a reduction of the Introduction to a maximum of 80 lines long.

L113: “mainly due “ is written with another font of font size.

L122: Please consider using “carried out” instead of “developed”.

L148: What exactly is 91CA? Please explain this first and then justify the use of cable yarding necessity.

L155: Maybe “designated” instead of “opened”?  Also, “ca.” can be avoided. In L156 “approximately” is better.

L159: in the uphill direction

L160: in each corridor

Table 1: I am not sure that “logging operation” information is needed in the table. Also, is there a better term for “Rise”?

L174-177: Simplify: “The work team consisted of three people, of which one was the yarder operator, the second unhooked, delimbed and bucked the trees, and the third was the choker-setter at the yarding site.” To “The work team consisted of the yarder operator, a second worker who unhooked, delimbed and bucked the trees, and a choker-setter at the yarding site”.

L216: …all indirect salary costs.

L231-233: Please provide a reference or proper justification of the followed approach.

Results and discussion: No information on the total number of cycle times and study duration is provided.

L252: How steep? Please define.

L258: ineffective time vs nonworking

L125-259: Please consider restructuring.

L242-276: A new table or figure, before Table 3, could be really helpful.

Table 5 is incomplete. For example, what is 18.30, 0.54 etc? The table structure should change. Also (s) doesn’t have to be included at the end each equation.

L295: “Generalized” model isn’t correct, try “general.

Table 7: …” including” vs “including”

L349: Another factor is personnel cost.

L331-408: It is necessary to work more on the text and identify paragraphs of common contents! The same applies also to the conclusions.

Generally, I would suggest that the authors repeat/enhance the statistical analysis.

Author Response

Dear reviewer 1,

we highly appreciate your effort and constructive comments regarding our submitted manuscript. In particular, the critics towards the methods section, addressing the uncertainties regarding paragraphs of common contents, did strongly contribute to improve the manuscripts quality, as we think. We are grateful for your comments and contribution so far and hope that the made changes are in a way how you envisioned them. The main comments are answered below, each answer starting with an ‘#’, to visually distinguish our text from yours. More detailed changes can be seen in the tracked changes of the current manuscript (uploaded as supplementary file).

L23: "decreased to" instead of “has decreased at”

#done

L24: Under the prevailing conditions

#done

L26 of the machine

#done

L27: The gross costs of uphill yarding in the studied dominance order was as follows: change to “The gross costs of uphill yarding in the studied dominance order was as follows”: I it necessary? The calculation of gross costs of uphill yarding has shown that…

#done

I would suggest to reconsider the keywords.

#done; steep terrainsalvage cutting; windbreak; windthrow; Natura 2000; cable yarder; performanceproductivity

L58: “of naturalistic interest” can be avoided. Sensitive areas is more than enough.

#done

L71: If you insist on using both words (limit/restrict) explain the thin difference between them in a longer or a new sentence. Another option could be “regulate”.

#done; we used “regulate”

L91: .. by the use of..

#done

While very informative, I would suggest a reduction of the Introduction to a maximum of 80 lines long.

#done; we have reduced Introduction paragraph to 1049 compared to the previous version of 1380 words

L113: “mainly due” is written with another font of font size.

#corrected

L122: Please consider using “carried out” instead of “developed”.

#done

L148: What exactly is 91CA? Please explain this first and then justify the use of cable yarding necessity.

#done; we have integrated with more details

L155: Maybe “designated” instead of “opened”?  Also, “ca.” can be avoided. In L156 “approximately” is better.

#done

L159: in the uphill direction

#done

L160: in each corridor

#done

Table 1: I am not sure that “logging operation” information is needed in the table. Also, is there a better term for “Rise”?

#done; we have eliminated “logging information” and changed “rise” in “Altitudinal difference between the corridor endpoints”

L174-177: Simplify: “The work team consisted of three people, of which one was the yarder operator, the second unhooked, delimbed and bucked the trees, and the third was the choker-setter at the yarding site.” To “The work team consisted of the yarder operator, a second worker who unhooked, delimbed and bucked the trees, and a choker-setter at the yarding site”.

#done

L216: …all indirect salary costs.

#done

L231-233: Please provide a reference or proper justification of the followed approach.

#done; we have changed sentences.

Results and discussion: No information on the total number of cycle times and study duration is provided.

#done

L252: How steep? Please define.

#done

L258: ineffective time vs nonworking

#done

L125-259: Please consider restructuring.

#done; we have organized better the manuscript, reducing Introduction, adding a new figure 1. Results and Discussion were separated and linguistic check was carried out.

L242-276: A new table or figure, before Table 3, could be really helpful.

#done

Table 5 is incomplete. For example, what is 18.30, 0.54 etc? The table structure should change. Also (s) doesn’t have to be included at the end each equation.

#done; we are sorry for this forgetfulness.

L295: “Generalized” model isn’t correct, try “general.

#done;

Table 7: …” includung” vs “including”

#done;

L349: Another factor is personnel cost.

#done;

L331-408: It is necessary to work more on the text and identify paragraphs of common contents! The same applies also to the conclusions.

#done; we have organized better the manuscript, adding a new figure 3 (3a and 3b); Conclusion section was improved.

Generally, I would suggest that the authors repeat/enhance the statistical analysis.

We have repeat the statistical analysis. Equation on productivity takes in consideration the damage type which is also telling most of the corridor: the damage type was considered as factor in the general model.

Author Response File: Author Response.pdf

Reviewer 2 Report

The topic of the paper is interesting and has practical value for readers, especially those working in the practical forestry. The questions are sound and relevant. Introduction is built nicely and it justifies the the work well.  

The quality of the paper would be significantly improved if the aims of the work would be specified more explicitly. The current aims do not focus the work properly. The data is adequate for the  study, and the methods deserve to be presented more promptly. I suggest that the authors write down all the used equations so that the reader can follow the deduction easily. The verbal description of the calculations in the manuscript is currently a bit fuzzy. A figure describing the experiment (logging) setup with the corridors would clarify the storyline.  

When the deduction is written with the equations in Materials and Methods, the Results-chapter will become more focused.  I suggest separating Results from the Discussion. The tables in the manuscript do not follow the Forests layout (e.g. Table 5 is missing the column headings). Showing results for each corridor separately is not necessary, for example in Table 5. The study layout is clearly hierarchial: same study has been conducted in corridors A, B, and C, but the main interest is in general results, not the individual corridors. Authors could consider using mixed effect model -regression and using the corridor as a random-effect. This would wrap up the results into one regression model that contains the information of variation between the corridors. After mixed linear model analysis, Tables 3 and 4 could be condensed to mean values and variation between corridors and variation inside the corridor. Most likely this will not change the results but would serve the results for the reader in a more structured way.

Specific comments

Add symbols and abbreviations into the end of the manuscript, see Forests template, and include the units there. After the first definition, use the abbreviations.

Table 1: Use Forests format, correct scientific name is Pinus sylvestris L.

Table 2: Table format

Line 206: give the six work elements and their descriptions, this is vital information in this article

Line 227: unit of Q is not correct?

Lines 237-238, remove.

Tables 5 and 6: Revise, include column lables and use forests format. These will be changed if mixed effect models  are used.

The overall merit of the paper is good, but I feel that revision of Materials and Methods, and separation of Results and Discussion would improve the manuscript.  

Author Response

Dear reviewer,

we highly appreciate your comments and contribution to the genesis of this manuscript. In particular, the first comment helped us to improve the overall quality. We agree, that the objective of the current study was not clearly described in the last version of the manuscript. Still, as you can see in the tracked changes of the current manuscript (supplementary file), more modifications were facilitated. We have added equations used in M&M and one figure to describe the experiment (logging) setup with the corridors. Aim of the study was corrected and improved. About your suggestion to modify statistical approach using mixed effect model-regression, we considered that this was done in the manuscript. In fact, equation on productivity takes in consideration the damage type which is also telling most of the corridor: the damage type was considered as factor in the general model. The reason for developing separate models for the corridors could be that, by this work, we have developed predictive models which also apply to a particular condition of the damage type. As such, if in a given forest one finds only one damage type, he/she could apply a specific model.

In the following, your addressed concerns are answered, starting with a ‘#’.

Specific comments

Add symbols and abbreviations into the end of the manuscript, see Forests template, and include the units there. After the first definition, use the abbreviations.

# done

Table 1: Use Forests format, correct scientific name is Pinus sylvestris L.

# done

Table 2: Table format

# done

Line 206: give the six work elements and their descriptions, this is vital information in this article

# done; six work elements and their descriptions were added in M&M.

Line 227: unit of Q is not correct?

# done; there was  a mistake

Lines 237-238, remove.

# done;

Tables 5 and 6: Revise, include column lables and use forests format. These will be changed if mixed effect models  are used.

# done;

The overall merit of the paper is good, but I feel that revision of Materials and Methods, and separation of Results and Discussion would improve the manuscript.

# done;

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

The authors have done a very good job by provising a much better version of the manuscript. A minor linguistic check is necessary and the following few points jave to be addressed (no line numbers rather position in text is provided in each case):

Abstract: correct offor

P1: Natura 2000 vs natura 2000

P2: “wet snow or and ice causes” to “… cause”

Equation 2: Please check so that P PMH are witten correctly.

P4: Please complete “However, no stud-ies have been identified to address the problem of”

Figure 3: The yellow colour used in this figure should be changed with another, more discernible, one.

Table 6: Consider removing the blank row in this table

A solid paper that would be of interest to the journal readership!

Author Response

Dear reviewer 1,

Thanks for your comments and we are apologies for an error during the last R1 submitted version. In fact, was changed in pdf format a not final version; indeed, it was dissimilar to word file of R1_word version where some your comments - round 2 - could find your approval.

Anyway, we have improved the manuscript with more attention.

Abstract: correct offor

Authors: Already changed in version R1_word and actually correct.

P1: Natura 2000 vs natura 2000

Authors: Already changed in version R1_word and actually correct.

P2: “wet snow or and ice causes” to “… cause”

Authors: thanks.

Equation 2: Please check so that P PMH are witten correctly.

Authors: Already changed in version R1_word and actually correct. PMH changed in subscript form.

P4: Please complete “However, no studies have been identified to address the problem of”

Authors: Already changed in version R1_word and actually correct.

Figure 3: The yellow colour used in this figure should be changed with another, more discernible, one.

Authors: done

Table 6: Consider removing the blank row in this table

Authors: done.

A solid paper that would be of interest to the journal readership!

Authors: Thanks a lot for your approval

Author Response File: Author Response.pdf