Round 1

Reviewer 1 Report

A.    Brief summary

This article investigates concurrently the ecological values and safety hazards of road tree alleys, based on the 6-component field examination. The presented case study area consists of a 14km long road transect located in the rural landscape in Poland. Conflicting arguments stated by the authorities on one side and by the experts on the other, are at core of this case. Authorities claim a number of trees to be a safety threat to the road users and thus, they should be removed. Authors examine these trees in order to avoid unnecessary tree felling and to inform about their ecological qualities. Results proved some important functions of the trees for the local fauna and flora species. The multiple assessment also proved a good or acceptable fitness of the investigated trees, pointing out that the tree felling is not necessary. The certain management interventions were applied to reduce potential risks, based on the results presented in this article (although this is insufficiently explained). Finally, the article calls for better resource management in decision making processes.

By my opinion, the main quality of this article dwells in its practicality – authors deal with the real-world problem investigating alternatives to sustain the ecological stability of green infrastructure on local scale. In this case, presented methodological tree hazard and value assessment could be considered by the decision makers as a supporting management tool. I suggest that the article is a good fit to the scope of Sustainability journal, nevertheless a major revision concerning the research methodology, final evaluation and also presentation of the results will be necessary prior to publishing.

B.     Broad comments

Generally, the article is addressing management and maintenance of trees, partly through the tree hazard assessment and partly through the evaluation of the tree ecological value, both applied on case study area. This is very relevant topic in the field of sustainability not only for rural, but also for urban landscapes. I see the main strengths of this research in its relatively broad applicability for the green infrastructure management. I would apprise a comprehensive description of the case study setting, and the methodology based on field investigation in concerned area.

On the other hand, I see some important methodological inconsistencies related to the research, which to a certain extent decrease the scientific value of the article. Also, I had difficulties in comprehending some of the sections and sentences throughout the article, mainly due to inconsistent writing and unclear use of language. These facts are indeed significant shortcomings, as they negatively affect the reputability and overall attractivity of the article. The language inconsistencies concern especially the introduction and discussion sections, where many of the sentences create confusion and unclarity. Some minor corrections could upgrade the article to a higher “level of understanding”, but to upraise the scientific value and soundness of the article, major methodological corrections (and/or changes) should be realized.

After reviewing the article, I see these shortcomings as the most acute:

1)      The methodological “six-examination framework” lacks the scientific soundness. By my opinion, there are some major shortcomings, which should be corrected in order to reach the appropriate scientific level of research (see the comments in C section of the review).

2)      The language needs to be revised, to make the article sound appropriately for use in the scientific journal. This mostly includes the word-order and phrasing, which sometimes blurs the meaning and inhibits a clear comprehension of author’s ideas from the reader’s perspective. I did not include comments on minor corrections in the following section (C), but the parts that are hard to comprehend are noted.

3)      The introduction, discussion, and conclusion parts need changes in the sentence formulations and phrasing.

4)      Some arguments are inappropriate to the scope of this article (out of its context), lacking references, or do not fit to the specific statements. This is mostly a case in the discussion part. Some comments addressing this issue are made in the following section.

C.    Specific comments and recommendations

Title

r.2: Reconsider the title formulation, particularly the phrase “value depreciations of …” which implies to the hedonic value of e.g. trees in this case. This is not a focus topic. Your evaluation is solely environmental, hence something like “depreciation of environmental values of the road alleys...”.

Abstract

r.20-21: “...vitality problems… deliver arguments” – I would not say that the vitality problems do deliver arguments, they are the reasons for those arguments.

r.24: …”to be felled for safety reasons” would maybe explain the situation better?

r.30: It is not clear to me, what exactly is author expressing by saying “… the environmental value… is hard to overestimate…”. I suggest this sentence to be rephrased.

Keywords

r.33: Key words like “green infrastructure management”, and “biodiversity conservation”, or similar, could be included to show also a broader classification of the topic (stated key words are very specific, not addressing the core idea of the article). On the other hand, the term “roadside trees management” is redundant.

Introduction

r.38-39: Alleys do belong to green infrastructure… not only have they have the potential, they are part of it.

r.43: I suggest replacing the term “simplification” for “homogenization”

r.47: Similarly, as in the comment from r.30, “hard to overestimate” makes no sense in this context. The benefits are underestimated or overlooked by the authority (in this case), or should not be neglected? (whereas the benefits are listed in the following sentence)

r.51-53: I have difficulties to understand where the author is heading with this statement. Ecological connectivity between the individual components (forest patch – alley, etc.) should contribute to the overall provision of multiple functions by trees, not the other way around. This is also stated two sentences later (r.55-58). Therefore, these sentences are contradicting each other.

r.72: Correction “attitude towards…”

r.74: What kind of infrastructure? There are many types of infrastructure, is it meant as road infrastructure? Or other technical infrastructure (electricity, product lines)? It needs to be specified.

r.76: “Loose rules” or “laws” would be more appropriate here. “Free” would basically indicate that no rules are applied.

r.79-80: I suggest rephrasing this sentence, it creates unnecessary confusion. Also, perhaps “collision with automobiles or traffic” not with “infrastructure”.

r.82: Again, confusing sentence.

r.92-93: I would not say that 5.1% of all accidents is “nothing”, but rather minor comparing to the other causes (e.g. speeding). After all, this means that drivers are exposed to danger also because of the unmaintained trees to some extent as well.

Section as a whole: By my opinion it is too general, with some repeating facts (e.g. safety problems vs. ecological value of the alleys), but without specific evaluation methods mentioned (used by other authors, and suitable as an inspiration for investigated case). Some addition of the trees / alleys / green infrastructure assessment and valuation methods (used especially as an argument within the related decision-making process) would be desirable, to improve the theoretical background of the article.

Materials and methods

r.105: phrase “Case study” defines this paragraph more accurately, because broader settings are described i.e. not only the area itself but also the conflict.

r.117-118: “the area of research” has a different meaning, “investigated/studied area” or “the area where research was conducted” would fit better in this context.

r. 126-127: I miss an explanation of “tree segments” and “trees in the segment” terms. The distances are almost identical in both cases. What is the reason for this division?

r. 136 – Figure 1: please add a small “sub-figure” with the position of the research area in the context of whole Poland.

r.142: correction: “both flora and fauna”

r. 140-204 – “Methods” section: This section should be re-written from two main reasons: (1) It does not provide methodologically sound framework (despite the fact that “6 examination methods” were really used, the whole approach does not provide consistent “examination framework” – see further comment); and (2) the methods are not comparably described (some references are missing – methods 1,3,4), methods 1-4 are described much more briefly than methods 5 and 6.

Ibid: The comprehensive framework should comprise not only 6 complementary and independent methods, but also a broad mutual theoretical background and final “synthesis” valuation (assessment). These aspects are completely missing. I see a possible improvement of the approach e.g. in adding the 2-aspects final valuation of the trees / alleys : (1) Safety valuation (synthesis of the steps / methods 1-3) and (2) Ecological-environmental valuation (synthesis of the steps / methods 4-6). Of course, some relative or absolute valuation scale should be also set (based on some literature sources). On the other hand, nor this step do avoid some of the other theoretical / methodological constraints resulting from the used approach – inconsistencies between evaluation of 2 trees in method 3; 28 trees in methods 1,2,4 and whole 14-km alley in methods 5,6; absenting the evaluation of other important ecological functions and criteria (e.g. micro-climatic function, air purification, biodiversity promotion, but also natural-historical and aesthetical value….). Finally, authors should seriously deal also with the problem of “trade-offs” between two main obtained value systems – safety vs. ecological value.

r.201: I suggest adding that the survey was concerned about the “ecological value” of … Value alone is very general term and also misleading in this case.

r.202-204: I believe, this belongs to the “funding section” in the end of article, not necessary to be mentioned in the methods.

Results

r. 206-222 Significant part of the section “Risk assessment” – the text is not about the scope of the section, but about species composition and some parameters of the trees. By the way, the sub-section with some basic parameters and information about investigated trees (alleys) is missing and would be beneficial.

r. 223-228: Some criteria for the final risk assessment are missing – both in the methods section and here. Therefore, it is not clear on what criteria the tree classification B-D was based, as well as the safety recommendations presented in table 1. 

r.210: Word-order. “There also exists additional species….”?

r.234: Table 1: Confusing caption. I think it was supposed to be written as two separate sentences.

r.222: I think, commonly used expression is “natural monument”.

r.223-224: Confusing sentence.

r. 236-258: 3.3 Pulling tests: By my opinion, this could be only supplementary method used for the stability and health state assessment of the trees (within the research, it was applied only for 2 trees). Therefore, I don´t recommend presenting this method as comparable / equivalent to other used methods.

r. 253-258: This paragraph belongs to the 3.4 section.

r. 261, 266: I am not sure, if the terms of “specimens” or “individuals” could be used regarding the lichen taxonomy group.

r. 263: … observed on studied tree… which one tree? One specific tree or all 28 investigated trees?

r. 275-276: what does it mean “…minimum distance between groups of trees…?

r. 279: Not at least 10 bat species were recorded? (unidentified Myotis sp. is 10^th in order…)

r. 294-295: there is a mistake in the list of species (2x – Eptesicus serotinus)

r.310-311: I suggest re-writing this sentence, it is very inconsistent.

r.313-315: The same issue here. Also, “within the 2000m radius from each other”

r. 311-312: Is it correct to use the term “settlements” in case of beetles? (consider using terms habitat, shelter…)

r. 320-321: What does the term “fauna wealth of trees” mean? Please use the more appropriate term (e.g. “good habitats preconditions”), because the term “wealth of trees” could indicate the “health state” of trees.

Discussion

r.325: Which tree is it? The results did not indicate any defected trees, nor the pulling test proved any tree to be unsafe, thus, certain measures clarifying its inappropriateness need to be mentioned.

r. 328-332: It is not clear, based on what criteria are the presented measures proposed and realized – are these recommended by the research team or are they not related to presented research? If the first case is true, some criteria for proposing relevant measures should be mentioned within the methodology section.

r.344-346: Very inconsistent sentence. It is better to write it separately in two sentences for instance: 1) describe the traditional approach; and then 2) the ecological importance of old-growth trees compared with young offsprings.

r.348-350: The same issue, inconsistently written sentence.

r.352-355: The same issue. Reader needs to repeat the whole sentence to fully understand in what way is the second part linked to its idea.

r.373-376: Is this a suggestion by authors? Then put it that way: “We think”, “In our opinion”, etc., elsewise, in case of the statement: “…preservation will bring ecological and economic profits to the local government and inhabitants by touristic popularization”, some references will be necessary to prove it. Also, more visitors = higher pressure on the ecosystem (e.g. disturbance for fauna) and thus, I would question any additional ecological gains. I am not sure about the weight of this argument.

r.377: Why “also”? This is the focus of the study which was just discussed. This sentence should affirm that stance. I suggest excluding word “also” here.

r.380-381: Nice concluding sentence, but the research itself did not fulfil such standards. 

Section as a whole: Good discussion should be based on arguments obtained from own research, compared to other relevant research, which have used similar or different approach to the same / similar investigated problem.  Unfortunately, this aspect is almost completely missing – by my opinion, this is caused by lack of theoretical and methodological “inspiration” (from other authors) included in the theoretical and methodological parts of the article. Also, the discussion presents some claims, which are not supported by author´s research (e.g. the context of ecosystem services provided by trees, habitat and landscape values, educational function…). 

Conclusions

r.383: Maybe a better expression is “the six-component examination framework”?

r.385: “comprehensive measures approach”? I think this could be re-defined.

r.386: Value is a broad expression – do you mean ecological value? Be more specific. By my opinion, two different “values” are crucial in the research context: health state (security value)  and ecological value of the trees.

r.388: I disagree with the statement: “The study has revealed in detail multifunctional benefits of road trees” – besides the tree safety assessment, the study has revealed only certain ecological functions that alleys represent in local ecosystems, but there was no analysis performed on derived benefits. Maybe it can be used as a supportive argument in the discussion part, with references on benefits (ecosystem services) that the trees provide to humans. I would suggest excluding it from the conclusion as it was not an object of this research – see also the previous general comments.

r.393-395: I see two contradicting ideas here: residents view alleys in utilitarian perspective and residents are apprehensive about the alleys. These are actually two different meanings as utilitarian tends to look at the productive qualities of nature (e.g. wood as a raw material for use), whereas if I am apprehensive, I would be afraid of its future and thus, I incline to nature conservation.

r.395-397: “Further studies should be conducted to clarify the ways of viable implementation of the full procedures into decision making…”? Because, the studies alone will not force their implementation, they can show the viable ways to direct the implementation.

Author Response

Comments on the review by Reviewer 1

Title

r.2: Reconsider the title formulation, particularly the phrase “value depreciations of …” which implies to the hedonic value of e.g. trees in this case. This is not a focus topic. Your evaluation is solely environmental, hence something like “depreciation of environmental values of the road alleys...”.

·        The title has been changed.

Abstract

r.20-21: “...vitality problems… deliver arguments” – I would not say that the vitality problems do deliver arguments, they are the reasons for those arguments.

·        The main reason for tree removal is the safety aspect. Road authorities often believe that „trees kill the drivers”. Vitality problems serve only as additional arguments in the decision making process.

r.24: …”to be felled for safety reasons” would maybe explain the situation better?

·        Corrected

r.30: It is not clear to me, what exactly is author expressing by saying “… the environmental value… is hard to overestimate…”. I suggest this sentence to be rephrased.

·        The sentence has been rephrased.

Keywords

r.33: Key words like “green infrastructure management”, and “biodiversity conservation”, or similar, could be included to show also a broader classification of the topic (stated key words are very specific, not addressing the core idea of the article). On the other hand, the term “roadside trees management” is redundant.

·        The suggested key words have been added, and the term “roadside trees management” has been removed.

Introduction

r.38-39: Alleys do belong to green infrastructure… not only have they have the potential, they are part of it.

·        Corrected

r.43: I suggest replacing the term “simplification” for “homogenization”

·        Corrected

r.47: Similarly, as in the comment from r.30, “hard to overestimate” makes no sense in this context. The benefits are underestimated or overlooked by the authority (in this case), or should not be neglected? (whereas the benefits are listed in the following sentence)

·        The sentence has been removed.

r.51-53: I have difficulties to understand where the author is heading with this statement. Ecological connectivity between the individual components (forest patch – alley, etc.) should contribute to the overall provision of multiple functions by trees, not the other way around. This is also stated two sentences later (r.55-58). Therefore, these sentences are contradicting each other.

·        Confusing sentences has been removed.

r.72: Correction “attitude towards…”

·        Corrected.

r.74: What kind of infrastructure? There are many types of infrastructure, is it meant as road infrastructure? Or other technical infrastructure (electricity, product lines)? It needs to be specified.

·        The type of infrastructure has been specified.

r.76: “Loose rules” or “laws” would be more appropriate here. “Free” would basically indicate that no rules are applied.

·        Corrected.

r.79-80: I suggest rephrasing this sentence, it creates unnecessary confusion. Also, perhaps “collision with automobiles or traffic” not with “infrastructure”.

·        The sentences has been removed/rephrased.  

r.82: Again, confusing sentence.

·        Corrected.

r.92-93: I would not say that 5.1% of all accidents is “nothing”, but rather minor comparing to the other causes (e.g. speeding). After all, this means that drivers are exposed to danger also because of the unmaintained trees to some extent as well.

a. The sentence has been rephrased.

Section as a whole: By my opinion it is too general, with some repeating facts (e.g. safety problems vs. ecological value of the alleys), but without specific evaluation methods mentioned (used by other authors, and suitable as an inspiration for investigated case). Some addition of the trees / alleys / green infrastructure assessment and valuation methods (used especially as an argument within the related decision-making process) would be desirable, to improve the theoretical background of the article.

·        As there are very few papers similar to ours, we were not able to present a wide theoretical background of the article. However, more citations and detailed explanations have been added in order to improve the quality of the paper. 

Materials and methods

r.105: phrase “Case study” defines this paragraph more accurately, because broader settings are described i.e. not only the area itself but also the conflict.

·        The paragraph’s title has been changed.

r.117-118: “the area of research” has a different meaning, “investigated/studied area” or “the area where research was conducted” would fit better in this context.

·        Corrected.

r. 126-127: I miss an explanation of “tree segments” and “trees in the segment” terms. The distances are almost identical in both cases. What is the reason for this division?

·        The sentence concerning the distance between tree segments has been deleted, as it was confusing and did not provide any necessary information. The only information left is the distance between trees in the alley: „The distance between trees in segment is ca. 6-8 m.”

r. 136 – Figure 1: please add a small “sub-figure” with the position of the research area in the context of whole Poland.

·        A map of Poland has been added presenting location of the investigated area (Gamerki).

r.142: correction: “both flora and fauna”

·        Corrected

r. 140-204 – “Methods” section: This section should be re-written from two main reasons: (1) It does not provide methodologically sound framework (despite the fact that “6 examination methods” were really used, the whole approach does not provide consistent “examination framework” – see further comment); and (2) the methods are not comparably described (some references are missing – methods 1,3,4), methods 1-4 are described much more briefly than methods 5 and 6.

Ibid: The comprehensive framework should comprise not only 6 complementary and independent methods, but also a broad mutual theoretical background and final “synthesis” valuation (assessment). These aspects are completely missing. I see a possible improvement of the approach e.g. in adding the 2-aspects final valuation of the trees / alleys : (1) Safety valuation (synthesis of the steps / methods 1-3) and (2) Ecological-environmental valuation (synthesis of the steps / methods 4-6). Of course, some relative or absolute valuation scale should be also set (based on some literature sources). On the other hand, nor this step do avoid some of the other theoretical / methodological constraints resulting from the used approach – inconsistencies between evaluation of 2 trees in method 3; 28 trees in methods 1,2,4 and whole 14-km alley in methods 5,6; absenting the evaluation of other important ecological functions and criteria (e.g. micro-climatic function, air purification, biodiversity promotion, but also natural-historical and aesthetical value….). Finally, authors should seriously deal also with the problem of “trade-offs” between two main obtained value systems – safety vs. ecological value.

·        The section “Methods” has been reorganized, and the graph has been added.  

r.201: I suggest adding that the survey was concerned about the “ecological value” of … Value alone is very general term and also misleading in this case.

·        Corrected.

r.202-204: I believe, this belongs to the “funding section” in the end of article, not necessary to be mentioned in the methods.

·        The sentence has been removed.

Results

r. 206-222 Significant part of the section “Risk assessment” – the text is not about the scope of the section, but about species composition and some parameters of the trees. By the way, the sub-section with some basic parameters and information about investigated trees (alleys) is missing and would be beneficial.

·        The sub-section has been added.

r. 223-228: Some criteria for the final risk assessment are missing – both in the methods section and here. Therefore, it is not clear on what criteria the tree classification B-D was based, as well as the safety recommendations presented in table 1. 

·        Criteria for the final risk assessment and additional citations have been added to the section “Methodology” (2.1.1) .The tests were carried out by experts specializing in each of the 6 research methods, and they are the authors of that paper. We used methodology of Roloff and ISA risk classes – according to them assigning to classes is made by an expert who assesses features of a tree taking into account factors provided in the methodology.

r.210: Word-order. “There also exists additional species….”?

There also exists additional species in old-growth forest composition: common aspen (Populus tremula), sycamore maple (Acer pseudoplatanus) and apple tree (Malus domestica). ?????

·        The sentence has been rewritten. “Additional species were also found in old-growth forest composition:…”

r.234: Table 1: Confusing caption. I think it was supposed to be written as two separate sentences.

·        Corrected.

r.222: I think, commonly used expression is “natural monument”.

·        Corrected.

r.223-224: Confusing sentence.

·        Corrected.

r. 236-258: 3.3 Pulling tests: By my opinion, this could be only supplementary method used for the stability and health state assessment of the trees (within the research, it was applied only for 2 trees). Therefore, I don´t recommend presenting this method as comparable / equivalent to other used methods.

·        We agree. Pulling test is a supplementary method – used for selected trees, in case more data is needed for the assessment of the stability. Pulling test is a complicated and time consuming method of research, that’s why is rather used as a complementary method. We added explanation in the “Methodology” section.

r. 253-258: This paragraph belongs to the 3.4 section.

·        Corrected.

r. 261, 266: I am not sure, if the terms of “specimens” or “individuals” could be used regarding the lichen taxonomy group.

·        The term “specimens” is commonly used in the professional literature that we cite.  

r. 263: … observed on studied tree… which one tree? One specific tree or all 28 investigated trees?

·        On all the 28 studied trees.

r. 275-276: what does it mean “…minimum distance between groups of trees…?

·        Corrected. The distance between trees cannot exceed 30 meters – otherwise some rare lichen populations cannot spread.

r. 279: Not at least 10 bat species were recorded? (unidentified Myotis sp. is 10^th in order…)

·        Corrected. 9 bat species were identified, there were also other species that the expert was not able to identify.

r. 294-295: there is a mistake in the list of species (2x – Eptesicus serotinus)

·        Corrected.

r.310-311: I suggest re-writing this sentence, it is very inconsistent.

·        Corrected.

r.313-315: The same issue here. Also, “within the 2000m radius from each other”

·        Corrected.

r. 311-312: Is it correct to use the term “settlements” in case of beetles? (consider using terms habitat, shelter…)

·        Corrected.

r. 320-321: What does the term “fauna wealth of trees” mean? Please use the more appropriate term (e.g. “good habitats preconditions”), because the term “wealth of trees” could indicate the “health state” of trees.

·        Corrected.

Discussion

r.325: Which tree is it? The results did not indicate any defected trees, nor the pulling test proved any tree to be unsafe, thus, certain measures clarifying its inappropriateness need to be mentioned.

·        The tree has been described in the text, and the information was also clarified in the table.

r. 328-332: It is not clear, based on what criteria are the presented measures proposed and realized – are these recommended by the research team or are they not related to presented research? If the first case is true, some criteria for proposing relevant measures should be mentioned within the methodology section.

·        Safety measures were used according the VTA method procedure – we added that information in the “Methodology” section.

r.344-346: Very inconsistent sentence. It is better to write it separately in two sentences for instance: 1) describe the traditional approach; and then 2) the ecological importance of old-growth trees compared with young offsprings.

·        Corrected.

r.348-350: The same issue, inconsistently written sentence.

·        Corrected.

r.352-355: The same issue. Reader needs to repeat the whole sentence to fully understand in what way is the second part linked to its idea.

·        Corrected.

r.373-376: Is this a suggestion by authors? Then put it that way: “We think”, “In our opinion”, etc., elsewise, in case of the statement: “…preservation will bring ecological and economic profits to the local government and inhabitants by touristic popularization”, some references will be necessary to prove it. Also, more visitors = higher pressure on the ecosystem (e.g. disturbance for fauna) and thus, I would question any additional ecological gains. I am not sure about the weight of this argument.

·        Corrected.

r.377: Why “also”? This is the focus of the study which was just discussed. This sentence should affirm that stance. I suggest excluding word “also” here.

·        Corrected.

r.380-381: Nice concluding sentence, but the research itself did not fulfil such standards. 

·        The sentence has been deleted.

Section as a whole: Good discussion should be based on arguments obtained from own research, compared to other relevant research, which have used similar or different approach to the same / similar investigated problem.  Unfortunately, this aspect is almost completely missing – by my opinion, this is caused by lack of theoretical and methodological “inspiration” (from other authors) included in the theoretical and methodological parts of the article. Also, the discussion presents some claims, which are not supported by author´s research (e.g. the context of ecosystem services provided by trees, habitat and landscape values, educational function…). 

·        We have made changes adding more citations and explanations in the introduction and discussion sections.

Conclusions

r.383: Maybe a better expression is “the six-component examination framework”?

·        Corrected.

r.385: “comprehensive measures approach”? I think this could be re-defined.

·        Re-defined as “complementary measures approach”.

r.386: Value is a broad expression – do you mean ecological value? Be more specific. By my opinion, two different “values” are crucial in the research context: health state (security value)  and ecological value of the trees.

·        Yes, we meant environmental value, it has been added to the text.

r.388: I disagree with the statement: “The study has revealed in detail multifunctional benefits of road trees” – besides the tree safety assessment, the study has revealed only certain ecological functions that alleys represent in local ecosystems, but there was no analysis performed on derived benefits. Maybe it can be used as a supportive argument in the discussion part, with references on benefits (ecosystem services) that the trees provide to humans. I would suggest excluding it from the conclusion as it was not an object of this research – see also the previous general comments.

·        Corrected - moved to the “Discussion” section.

r.393-395: I see two contradicting ideas here: residents view alleys in utilitarian perspective and residents are apprehensive about the alleys. These are actually two different meanings as utilitarian tends to look at the productive qualities of nature (e.g. wood as a raw material for use), whereas if I am apprehensive, I would be afraid of its future and thus, I incline to nature conservation.

·        These are the issues we just wanted to highlight - the contradiction of utilitarian and safety perspective. We explained that briefly in the text.

r.395-397: “Further studies should be conducted to clarify the ways of viable implementation of the full procedures into decision making…”? Because, the studies alone will not force their implementation, they can show the viable ways to direct the implementation.

·        Supplemented in the text.

Author Response File: Author Response.docx

Reviewer 2 Report

The paper deals with a challenging and under-researched topic. The general structure of the paper is easy to follow, the different chapters are well balanced in length and contents. This being said, I have however some minor remarks regarding the paper in its present form.

1. Introduction

The introductory section sets the wider context and the debates that the research is contributing to. On the other hand, you mention two important concepts, green infrastructure and ecosystem services, without providing a clear definition. The two concepts should be developed. Furthermore, green infrastructure and ecosystem services should be correlated with tree alley.

2. Materials and Methods

2.1. Study area

The text from line 106 to 121 is confused. A description of the study areas is missing. Where is located the study area? In which part of Poland?

2.1. Methods

In relation to the risk assessment and vitality evaluation, it is not clear how classes and groups are assigned. Did you involve a group of experts?

4. Discussion

Discussion would probably benefit from the inclusion of other studies that dealt with the same kind of problems to compare results and methods.

5. Conclusions

Conclusions need to be improved in terms of limitations and innovative aspects of your study

Other comments

Moreover, you write several sentences without providing references that support it. For example, you state that “In Poland, tens of thousands of road trees were cut down as a result of such an approach.” (lines 80-81)

and

“It is worth noting, in Poland only 5,1 % of road accidents happen due to collision of vehicles with trees.” (lines 92-93)

Could you provide a reference to these sentences?

The title of the article is “Transit verus Nature. Value Depreciation of Road Alleys. Case study: Gamerki-Jonkowo, Poland”. Is the term “verus” correct?

Author Response

Comments on the review by Reviewer 2

1. Introduction

The introductory section sets the wider context and the debates that the research is contributing to. On the other hand, you mention two important concepts, green infrastructure and ecosystem services, without providing a clear definition. The two concepts should be developed. Furthermore, green infrastructure and ecosystem services should be correlated with tree alley.

·       Citations has been added, explaining both important concepts: green infrastructure and ecosystem services, especially in the urban forest management process. The term ”ecosystem services” was used many times in text in context of the alley. We correlated the idea of green infrastructure and ecosystem services more strongly with the alley.

2. Materials and Methods

2.1. Study area

The text from line 106 to 121 is confused. A description of the study areas is missing. Where is located the study area? In which part of Poland?

·       The area is situated in north-east of Poland, as it is described in lines 108-109. A new map was added to present the exact location. 

2.1. Methods

In relation to the risk assessment and vitality evaluation, it is not clear how classes and groups are assigned. Did you involve a group of experts?

·       Yes. The tests were carried out by experts specializing in each of the 6 research methods, and they are the authors of that paper. We used methodology of Roloff and ISA risk classes – according to them assigning to classes is made by an expert who assesses features of a tree taking into account factors provided in the methodology. Citations have been added to describe the methods more clearly.

4. Discussion

Discussion would probably benefit from the inclusion of other studies that dealt with the same kind of problems to compare results and methods.

·       There are very few studies dealing with the same problem, however some citations have been added.

5. Conclusions

Conclusions need to be improved in terms of limitations and innovative aspects of your study

·       Conclusions concerning limitations and innovative aspects of the study have been added.  

Other comments

Moreover, you write several sentences without providing references that support it. For example, you state that “In Poland, tens of thousands of road trees were cut down as a result of such an approach.” (lines 80-81)

·       Corrected

and

“It is worth noting, in Poland only 5,1 % of road accidents happen due to collision of vehicles with trees.” (lines 92-93)

Could you provide a reference to these sentences?

·       The reference is in the text: „Collision of vehicles and trees is the reason for 5,1% of road accidents, which is rather minor comparing to other causes [50]. The main reason for accidents is the exceeding of speed limits by drivers [51,52].” We added additional citations as well.

The title of the article is “Transit verus Nature. Value Depreciation of Road Alleys. Case study: Gamerki-Jonkowo, Poland”. Is the term “verus” correct?

·       The term has been corrected.

Author Response File: Author Response.docx

Reviewer 3 Report

This paper presents the results of examination on environmental and ecological values of road alleys, and tree risk assessment. The paper is generally well-written, and the topic is interesting. The results of this study could provide an evidence to support the notion that trees along roadsides should be maintained rather than removed.  I really enjoyed reading this work. However, I have some comments and suggestions for the improvement of this paper.

Page 2 line 85-87. The authors stated "road supervisors who should take care of tree alleys, do not use transparent methodology of evaluation nor tree classification" it is better to rewrite this sentence to avoid any possible conflict. Otherwise, a citation should be provided to support this statement.

In the introductory part, please indicate the significance of animal species living in the alleys to ecosystem functions. In case that those animals are disappeared from a road alley, what are possible negative impacts on ecological systems. Also, please add literature showing adverse ecological impacts caused by tree removal. 

I am curious why only beetle species, lichens species, bat fauna were selected to investigate? Are there other species in an alley? Please indicate a possible reason to select these species to investigate in this study.

Page 2  line  88-89. Meanwhile, researchers point out that there is a possibility for avoidance of cutting old road alleys and ensuring traffic safety at the same time... Please add more explanation on how to preserve old trees together with ensure road safety?

Page 3 line 108, 31 or 28 trees which were planned to remove?

Page 3 line 109. there was also a plan to remove the whole alley in the future in order to ................. Please insert a citation.

Page 3 line 114. Please insert a citation for this sentence "Osmoderma barnabita was indicated as a protected specie"

In the methodology section, page 5 line 147, regarding risk assessment, please indicate indicators used to assess the risk. Please also explain how each level of risk really means.

Page 11, line 283, why Gamerki wielkie is indicated as a vulnerable place for local bat population?

In the discussion part, please add more the discussions on the results of examination rather than mostly emphasize on recommendation. For instance 

- please clearly explain characteristics of the tree which should be removed. How can it cause problems with road safety?

-  why were 9 bat species found in the road alley? Explain conditions of trees and environmental conditions which support the living of those bats. 

- Also include the discussion on the result of lichen and hermit beetle species examination.

- Relevant previous studies should be reviewed and used to support this finding. 

- Values of these existing species to environmental and ecological systems should be added as well.

Good luck

Author Response

Comments on the review by Reviewer 3

Page 2 line 85-87. The authors stated "road supervisors who should take care of tree alleys, do not use transparent methodology of evaluation nor tree classification" it is better to rewrite this sentence to avoid any possible conflict. Otherwise, a citation should be provided to support this statement.

·       Citation has been added.

In the introductory part, please indicate the significance of animal species living in the alleys to ecosystem functions. In case that those animals are disappeared from a road alley, what are possible negative impacts on ecological systems. Also, please add literature showing adverse ecological impacts caused by tree removal. 

·       Citations have been added underlining results of road development and management on native species extinction.

·       Citations presenting ecological impact caused by tree removal have been added.

I am curious why only beetle species, lichens species, bat fauna were selected to investigate? Are there other species in an alley? Please indicate a possible reason to select these species to investigate in this study.

·       We decided to investigate the presence of species which are under protection of law. Confirmation of the presence of the species led to saving of the alley. Starting the research, we expected the species would be found as the area was still “very natural”, and not suffered from the urbanization process. However, many road alleys in the area of Warmia are removed, because such investigations as ours are not carried out.

Page 2  line  88-89. Meanwhile, researchers point out that there is a possibility for avoidance of cutting old road alleys and ensuring traffic safety at the same time... Please add more explanation on how to preserve old trees together with ensure road safety?

·       Explanations and citations have been added.

Page 3 line 108, 31 or 28 trees which were planned to remove?

·       Corrected. 28 trees.

Page 3 line 109. there was also a plan to remove the whole alley in the future in order to ................. Please insert a citation.

·       Citation has been added.

Page 3 line 114. Please insert a citation for this sentence "Osmoderma barnabita was indicated as a protected species"

·       Citation has been added.

In the methodology section, page 5 line 147, regarding risk assessment, please indicate indicators used to assess the risk. Please also explain how each level of risk really means.

·       Explanations and citations have been added. The investigations were carried out by experts specializing in each of the 6 research methods, and they are the authors of the paper. We used methodology of Roloff and ISA risk classes – according to them assigning to classes is made by an expert who assesses features of a tree taking into account factors provided in the methodology.

Page 11, line 283, why Gamerki wielkie is indicated as a vulnerable place for local bat population?

·       Corrected – the word was improper. We changed “vulnerable” into “plentiful”.  

In the discussion part, please add more the discussions on the results of examination rather than mostly emphasize on recommendation. For instance 

- please clearly explain characteristics of the tree which should be removed. How can it cause problems with road safety?

·       Explained.

-  why were 9 bat species found in the road alley? Explain conditions of trees and environmental conditions which support the living of those bats. 

·       Explanation has been added.

- Also include the discussion on the result of lichen and hermit beetle species examination.

·       Included.

- Relevant previous studies should be reviewed and used to support this finding. 

·       Corrected.

- Values of these existing species to environmental and ecological systems should be added as well.

a. Corrected.

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

A summary (2^nd review)

As suggested after the first review, authors have revised all the sections to some degree but mostly the methodology, results and related discussion. Visualization of the methodological assessment of the trees (six-steps) helps to better comprehend the research approach. This is seen as major modification after the 1^st review. Overall approach to the research process is now more profound. Similarly, the final resolution (concluding results) is now clear about which and how many trees were approved or denied by the assessment. However, some revision is still needed.

Further comments concern only the parts that have been revised. At last a final observation is stated.

 Broad comments 

+(1) better explanation of the methodology; (2) more elaborated results and discussion

- (1) language: some parts lack more professional soundness; (2) text order (some parts belong to different sections, or order of information within the section); (3) strength of the discussion (relates to previous two points)

 Specific comments

 113-120: I would say that this section belongs to methods.

 170-172: The map is duplicated.

 192: I would move the Figure 3. (277-279) up here and then describe the partial methods, thus visualize them first. Also, make sure the boxes belonging to the "six methods" are highlighted. For instance, if you look at the Figure 3. the "Identification of trees to be removed" as well as "Identification of trees with protected species" seem to be part of this methods, but they are part of the evaluation I believe. Maybe divide it into general phases of the process as e.g.: (1) type of valuation, (2) six-step assessment, (3) identification, (4) resolution (This is just a recommendation)

 300-305:  NOTE: only 3 tree species have been assessed during your research, while you are talking about all the species in the transect (282-295). In this case, I suggest presenting the overall composition of the transect in the case study description to introduce the area. Or does it make any contribution to your results? Re-consider this part.

Recommendation: A histogram showing the overall species structure of the alley with related abundance (in % from the text above) of dominant species. Information of these additional species could be included as "other" because I do not see its relevance in the context of your research.

 298: Some more information about the criteria of the "natural monument"? This was mentioned in the review n.1 with no further revisions found.

 430: ...long, safe live?... Maybe: ...is not safe for the road users.

 437-443: I suggest moving some of this information up to introduction. Clarify why these species are being investigated, why they are important, before you present the results. I see that you discuss it later (489-505), consider relocating the basic information about it to the introduction.

 445-446: ...cannot be felled... is little too strong statement. Maybe: should not be felled. I am certainly sure, this is not highly relevant factor for tree to be conserved when the road management department makes decisions.

 535-548: This whole part (blue) is a nice conclusion of the discussion. But try to fix the language and phrasing so the message sounds stronger.

 Final statement

I did not account for the language misinterpretation during the second review, but I do recommend forwarding article for a correction of the written part (language check) prior to submission as the professional soundness remains mild.

I do agree that you have accomplished the objective of your research, justifying which trees are and which are not appropriate to be kept in place, including maintenance recommendations.

Author Response

Comments on the review by Reviewer 2

As suggested after the first review, authors have revised all the sections to some degree but mostly the methodology, results and related discussion. Visualization of the methodological assessment of the trees (six-steps) helps to better comprehend the research approach. This is seen as major modification after the 1^st review. Overall approach to the research process is now more profound. Similarly, the final resolution (concluding results) is now clear about which and how many trees were approved or denied by the assessment. However, some revision is still needed.

Further comments concern only the parts that have been revised. At last a final observation is stated.

 Broad comments 

+(1) better explanation of the methodology; (2) more elaborated results and discussion

- (1) language: some parts lack more professional soundness; (2) text order (some parts belong to different sections, or order of information within the section); (3) strength of the discussion (relates to previous two points)

Specific comments

 113-120: I would say that this section belongs to methods.

We would prefer to leave that explanation in the Introduction section. The explanation gives a wide background for the risk assessment approach. The VTA method we used in our study was described in detail in the Methods section.

170-172: The map is duplicated.

We left the right one map – presenting the investigated area on the territory of Poland.

 192: I would move the Figure 3. (277-279) up here and then describe the partial methods, thus visualize them first. Also, make sure the boxes belonging to the "six methods" are highlighted. For instance, if you look at the Figure 3. the "Identification of trees to be removed" as well as "Identification of trees with protected species" seem to be part of this methods, but they are part of the evaluation I believe. Maybe divide it into general phases of the process as e.g.: (1) type of valuation, (2) six-step assessment, (3) identification, (4) resolution (This is just a recommendation)

Figure 3 has been removed into row 192 and corrected according to suggestions.

300-305:  NOTE: only 3 tree species have been assessed during your research, while you are talking about all the species in the transect (282-295). In this case, I suggest presenting the overall composition of the transect in the case study description to introduce the area. Or does it make any contribution to your results? Re-consider this part.

We decided to leave the presentation of overall composition of the species in the alley in the Results section, again it gives background for the six method of assessment – it seems important in the context of risk and protected species composition.

Recommendation: A histogram showing the overall species structure of the alley with related abundance (in % from the text above) of dominant species. Information of these additional species could be included as "other" because I do not see its relevance in the context of your research.

We submitted the histogram as supplementary material.

 298: Some more information about the criteria of the "natural monument"? This was mentioned in the review n.1 with no further revisions found.

The criteria have been added.

 430: ...long, safe live?... Maybe: ...is not safe for the road users.

Corrected.

 437-443: I suggest moving some of this information up to introduction. Clarify why these species are being investigated, why they are important, before you present the results. I see that you discuss it later (489-505), consider relocating the basic information about it to the introduction.

The information has been moved to the Introduction section.  We left only information connected with Discussion.

 445-446: ...cannot be felled... is little too strong statement. Maybe: should not be felled. I am certainly sure, this is not highly relevant factor for tree to be conserved when the road management department makes decisions.

According to the Polish law, trees with protected species cannot be felled if they are safe for traffic.

 535-548: This whole part (blue) is a nice conclusion of the discussion. But try to fix the language and phrasing so the message sounds stronger.

And comment to one of final statements:

I did not account for the language misinterpretation during the second review, but I do recommend forwarding article for a correction of the written part (language check) prior to submission as the professional soundness remains mild.

This part (r.535-548) has been rewritten. Whole article has been submitted for editing and proofreading prior to submission.

 Final statement

I do agree that you have accomplished the objective of your research, justifying which trees are and which are not appropriate to be kept in place, including maintenance recommendations.

Author Response File: Author Response.docx