Spring’s Signal: Can Bud Burst Timing Enhance Resistance to Ash Dieback in Europe?

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Please consider the following comments for further improvement-

Abstract

To ensure that the primary idea is conveyed clearly and comprehensively, the abstract should provide a structured and accessible overview by separating the key findings and their significance.

Introduction

1. The introduction provides sufficient background information. However, a brief note on the linkage between phenological traits and the genetic elements of resistance to H. fraxineus may improve the understanding of the subject.

2. Although the assumptions are clear, a brief synopsis of the logic behind the association between early phenology and disease resistance would be helpful.

3. Ensure that the transitions between sections are seamless to maintain cohesion.

4. At the end, include a short summary that explains why this research is important and what it will contribute to the field.

Materials and Methods

1. More background would clarify the reasons behind some clones' exclusion from statistical evaluations.

2. It is necessary to provide a brief description of the orchard's soil type, elevation, or water table because these factors may have an effect on the health of the plants and the development of H. fraxineus.

3. A map or visual representation of the climatic zones, together with their interaction with the study site, can be incorporated to improve understanding.

4. Table 2 needs explicit labeling, especially for phrases like Ramet survival year 2020 and statistical analysis.

4. Explain why Borki 7301, for example, with 76.92% survival, was chosen above Hajnówka 5524, 33.33%).

5. It should be explained how sampling bias was minimized by selecting the collected shoot samples (e.g., at random or based on visible symptoms).

6. While the phenological stages 1–5 are clearly defined, think about elaborating on why these particular stages are important for evaluating health or ash resistance.

7. Avoid the use of highly technical terms without providing a brief explanation.

8. Please provide a concise explanation of the ecological significance of the eight variables that were chosen for the European ash distribution, as well as provide an explanation for the selection of six clusters as the most effective.

9. A reference may be added to illustrate how the PCA results are strengthened by bootstrap analysis.

10. Check for minor grammatical inconsistencies, particularly in the Methods section.

Results

1. The correlations between PC1 and PC2 are extensively described; yet, they can be simplified.

2. In Figure 3, Panel B involves additional explicit labels or annotations that will further explain the importance of variables in explaining variance.

3. The ellipses in Figure 4 for northeastern and eastern Poland are visually enlightening; nevertheless, it may be beneficial to provide a brief explanation of the reasons behind their importance.

4. The results (e.g., estimates, confidence intervals) are undoubtedly reported in Table 4, but they also offer a more natural interpretation of the fixed effect coefficients.

5. The density distributions are informative; however, it is preferable to sum up the patterns in the caption.

6. Please elaborate on the importance of the poor correlations in 2018 and 2019 compared to the stronger correlation in 2020 (R² = 0.37).

7. The density distributions in Figure 5 are informative; meanwhile, it is advisable to review the patterns in the caption briefly.

8. Ensure that figures and tables have been identified by clear labels and descriptive captions. This helps readers interpret the results without referring back to the main text.

9. Avoid excessive reliance on technical terms without explanation.

Discussion

1. In the discussion, a brief note on the linkage between phenological traits and the genetic elements of resistance to H. fraxineus (if exists) may improve the understanding of the subject.

2, The paper may briefly discuss how comparable concepts may be applied globally, particularly in areas where invading diseases impact other ash species.

2. Although the bioclimatic analysis identifies regional variations, the topic might be strengthened by a more thorough explanation of how these variations affect susceptibility and adaptability.

3. The paper should specifically highlight how it advances the science, especially by recognizing phenology as a resistance feature.

4. Making specific suggestions for further research would provide this field with a clear path forward.

Conclusion

1. A clear call to action emphasizing the importance of incorporating these findings into conservation programs will strengthen the conclusion, which is already evident. 2. By providing forest managers and environmentalists with intelligent information, its use can be enhanced.

3. An explanation of how future research can address information gaps related to the genetic basis of phenology and its connection to environmental stresses could strengthen the conclusions and guide subsequent investigations.

 

 

Author Response

Dear Reviewer,

We sincerely thank you for your thorough analysis of our manuscript and your valuable comments and suggestions. Your insights have significantly contributed to improving the quality and clarity of our work.

Below, we provide detailed responses to all the points you raised. The changes have been incorporated into the manuscript and are clearly marked for better visibility. We trust that our responses and the revisions made will meet your expectations.

Once again, thank you for your time and effort in helping us enhance our manuscript.

Abstract

To ensure that the primary idea is conveyed clearly and comprehensively, the abstract should provide a structured and accessible overview by separating the key findings and their significance.

Thank you for highlighting the need to revise the abstract. The text has been updated, and we hope that the current version meets the reviewer's expectations.

Introduction

1. The introduction provides sufficient background information. However, a brief note on the linkage between phenological traits and the genetic elements of resistance to H. fraxineusmay improve the understanding of the subject.

Thank you for your valuable comment. In response, we have added a brief discussion to the Introduction section, linking phenological traits with genetic changes that influence resistance to Hymenoscyphus fraxineus. This addition highlights the potential genetic basis of phenological traits and their importance to resistance mechanisms, aligning with your suggestion and enhancing the understanding of the topic.

2. Although the assumptions are clear, a brief synopsis of the logic behind the association between early phenology and disease resistance would be helpful.

Thank you for this suggestion. To better explain the relationship between early phenology and resistance to Hymenoscyphus fraxineus, we have added a section to the Introduction that highlights the biological basis of this relationship.

3. Ensure that the transitions between sections are seamless to maintain cohesion.

Thank you for your comment. We have reviewed the manuscript to ensure that transitions between sections are smooth and cohesive.

4. At the end, include a short summary that explains why this research is important and what it will contribute to the field.

Thank you for your valuable comment. In response, we have added a brief summary at the end of the Introduction section to explain the significance of our study and its contribution to the field. We hope this addition meets your expectations and highlights the practical applications of the study’s findings in ash conservation and forest ecosystem management.

Materials and Methods

1. More background would clarify the reasons behind some clones' exclusion from statistical evaluations.

Thank you for your comment. To clarify the reasons for excluding certain clones, we have added a detailed explanation in the Methods section, highlighting the impact of low sample sizes on the results of the statistical analysis and the quality of inferences.

2. It is necessary to provide a brief description of the orchard's soil type, elevation, or water table because these factors may have an effect on the health of the plants and the development of  fraxineus.

Thank you for your valuable comment. In response to your suggestion, we have expanded the Methods section to include detailed information about the environmental conditions of the studied seed orchard.

3. A map or visual representation of the climatic zones, together with their interaction with the study site, can be incorporated to improve understanding.

Thank you for the suggestion. We would like to note that the mentioned visualization has been included in Figure 4.

4. Table 2 needs explicit labeling, especially for phrases like Ramet survival year 2020 and statistical analysis.

Corrected as per the reviewer’s suggestions.

5. Explain why Borki 7301, for example, with 76.92% survival, was chosen above Hajnówka 5524, 33.33%).

Thank you for the valuable suggestion for improving the text. To better emphasize the impact of clone sample size on the selection criteria, we have made the necessary revisions in the Methods section.

6. It should be explained how sampling bias was minimized by selecting the collected shoot samples (e.g., at random or based on visible symptoms).

Thank you for your valuable comment, which helped clarify the methods used. To better explain the approach for minimizing sampling bias, we have added an additional sentence to the Methods section, subsection 2.3.

7. While the phenological stages 1–5 are clearly defined, think about elaborating on why these particular stages are important for evaluating health or ash resistance.

Thank you for the suggestion. A sentence has been added to clarify the selection of specific developmental stages and their impact on ash tree resistance.

8. Avoid the use of highly technical terms without providing a brief explanation.

Thank you for the suggestion. We will make the necessary corrections to avoid any misunderstandings.

9. Please provide a concise explanation of the ecological significance of the eight variables that were chosen for the European ash distribution, as well as provide an explanation for the selection of six clusters as the most effective.

Thank you for your comment. In response, we have added sentences to section 2.5 explaining the ecological significance of the selected variables and justifying the choice of six clusters. We believe these modifications will enhance the understanding of the analyses conducted.

10. Check for minor grammatical inconsistencies, particularly in the Methods section.

Thank you for your comment. The text of the section has been submitted for grammatical correction.

Results

1. The correlations between PC1 and PC2 are extensively described; yet, they can be simplified.

The description of the capabilities has been simplified, which improves its readability.

2. In Figure 3, Panel B involves additional explicit labels or annotations that will further explain the importance of variables in explaining variance.

The caption of Figure 3 has been modified, which has significantly improved its clarity.

3. The ellipses in Figure 4 for northeastern and eastern Poland are visually enlightening; nevertheless, it may be beneficial to provide a brief explanation of the reasons behind their importance.

An additional description has been added to complement Figure 4.

4. The results (e.g., estimates, confidence intervals) are undoubtedly reported in Table 4, but they also offer a more natural interpretation of the fixed effect coefficients.

Thank you for your comment, which will improve the quality of the presented results. The changes made should enhance the manuscript.

5. The density distributions are informative; however, it is preferable to sum up the patterns in the caption.

Thank you for the suggestion. Changes have been made to improve the presentation of the results.

6. Please elaborate on the importance of the poor correlations in 2018 and 2019 compared to the stronger correlation in 2020 (R² = 0.37).

Thank you for pointing out this crucial aspect of the results, which was not described with the necessary attention. Additional information has been added in the Discussion section.

7. The density distributions in Figure 5 are informative; meanwhile, it is advisable to review the patterns in the caption briefly.

The suggested changes have been implemented.

8. Ensure that figures and tables have been identified by clear labels and descriptive captions. This helps readers interpret the results without referring back to the main text.

Thank you for your comment.

9. Avoid excessive reliance on technical terms without explanation.

Changes have been made to improve the structure of the text.

Discussion

1. In the discussion, a brief note on the linkage between phenological traits and the genetic elements of resistance to  fraxineus (if exists)may improve the understanding of the subject.

The recommendations made by the reviewer have been included in the Discussion part.

2. The paper may briefly discuss how comparable concepts may be applied globally, particularly in areas where invading diseases impact other ash species.

Thank you for the suggestion to enhance the presented text. In response, we have added a paragraph discussing the issue, supplemented with relevant references.

3. Although the bioclimatic analysis identifies regional variations, the topic might be strengthened by a more thorough explanation of how these variations affect susceptibility and adaptability.

The suggested changes have been implemented, contributing to improved precision in the text, for which we sincerely thank the reviewer.

4. The paper should specifically highlight how it advances the science, especially by recognizing phenology as a resistance feature.

In accordance with the recommendations, the paragraph in the Discussion section was modified to clearly articulate the significance of phenology as a resistance trait.

5. Making specific suggestions for further research would provide this field with a clear path forward.

A sentence was added in accordance with the reviewer’s recommendations.

Conclusion

1. A clear call to action emphasizing the importance of incorporating these findings into conservation programs will strengthen the conclusion, which is already evident.

Thank you for appreciating the presented results. The sentence suggested by the Reviewer has been added at the end of the Discussion section.

2. By providing forest managers and environmentalists with intelligent information, its use can be enhanced.

The information requested by the Reviewer has been added.

3. An explanation of how future research can address information gaps related to the genetic basis of phenology and its connection to environmental stresses could strengthen the conclusions and guide subsequent investigations.

The information requested by the Reviewer has been included.

 

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

This study examines the relationship between  particularly the timing of spring bud burst, and the susceptibility to Ash dieback (ADB). I have the following comments and suggestions:

1. Line 8-11, Please re-write this sentence.

2. Please provide some  main data in the abstract part.

3. Introduction part. Please provide more research advance about resistance from host aspect to ADB by Hymenoscyphus fraxineus.

4. Table 1 as supplementary 

5. Line 130, only one ramet for each clone? And this isolation method is not sensitive for assay of infection.

6. Figure 2. Diagram of ash bud development according to phenological phases 1-5. Please added real ash bud development pictures according to phenological phases 1-5.

7. 2.4. Phenotyping and Assessment of Tree Health. Tree Health?

8. Why not provide method and results for severity of ADB. I think this is very important for this  relationship study.

9. Please shorten the Conclusions .

Author Response

Dear Reviewer

Thank you for your constructive review of our manuscript. We appreciate your comments, which have helped us improve the quality of our work. Below, we provide detailed responses to each of your comments and suggestions.

We have made every effort to address the issues raised, implementing the recommended changes to the manuscript. For ease of review, we have included specific revisions in the attached text, with changes highlighted for greater clarity. We believe that the corrections made adequately address your comments and enhance the quality of the manuscript.

Once again, thank you for your feedback and the opportunity to improve our study.

1. Line 8-11, Please re-write this sentence.

Thank you for your comment. The sentence has been revised according to your suggestion. We hope that in its current form, it meets your expectations.

 

2. Please provide some  main data in the abstract part.

Thank you for the detailed analysis of the abstract. The authors have made significant changes to its content, adding additional information, which has substantially increased its informativeness for the reader. We hope that the changes made are satisfactory to the reviewer. Additionally, we would like to emphasize our readiness to make further modifications and adjustments if necessary.

 

3. Introduction part. Please provide more research advance about resistance from host aspect to ADB by Hymenoscyphus fraxineus.

The introduction has been expanded to include more information on the relationship between genetic information and spring phenology. The authors have emphasized the importance of developmental phases and their adaptive significance. Additionally, a concluding sentence has been added, correlating the conducted research with global threats to the species and helping the reader understand the practical and economic significance of the presented analyses.

 

4. Table 1 as supplementary 

As per the reviewer’s recommendation, Table 1 has been moved to the supplementary materials.

 

5. Line 130, only one ramet for each clone? And this isolation method is not sensitive for assay of infection.

Thank you for your comment regarding the sampling methodology used. We would like to clarify that the method applied in this study was intended solely to confirm the presence of H. fraxineus in the seed orchard. The study referenced by the reviewer did not focus on a detailed assessment of infection levels or sensitivity testing but was limited to establishing the presence of H. fraxineus. While we acknowledge the limitations of using a single ramet per clone, this approach was sufficient to achieve the objectives of the presented study. Future research conducted on the site discussed in the publication could incorporate a more comprehensive sampling strategy and an evaluation of infection dynamics.

 

6. Figure 2. Diagram of ash bud development according to phenological phases 1-5. Please added real ash bud development pictures according to phenological phases 1-5.

Unfortunately, as authors, we are unable to provide actual photographs for all developmental phases. The images taken in the field using a phone camera are of low quality and do not meet the standards required by the journal. Additionally, their inclusion does not provide significant additional value to the text, as the assessment of developmental phases was conducted in accordance with the international standards of the Trees4Future project, as detailed in the manuscript. We assure you that all field observations were carried out following the highest scientific standards. However, we would like to present one of the few preserved photographs, depicting the onset of bud burst in 2018, as an example.

7. 4. Phenotyping and Assessment of Tree Health. Tree Health?

We thank the reviewer for pointing out the imprecise term. Following the suggestion, the title has been corrected.

 

8. Why not provide method and results for severity of ADB. I think this is very important for this  relationship study.

We thank the reviewer for highlighting the importance of assessing the severity of ash dieback (ADB). We agree with the reviewer on the significance of understanding the relationship between phenology and susceptibility to infection. However, we would like to note that the primary aim of this study was to examine the timing of spring bud burst and its relationship with the overall health and survival of trees under varying levels of infection pressure. The severity of ADB was not directly investigated in this study, as our focus was on phenological and regional differences among clones. Nevertheless, we emphasize that crown damage and defoliation levels were assessed as indicators of tree health and the impact of confirmed infection. We appreciate your comment and acknowledge the importance of detailed assessments of ADB severity in future studies to further explore the relationships suggested by the reviewer.

 

9. Please shorten the Conclusions .

In accordance with the reviewer’s recommendations, the conclusion has been significantly shortened, retaining only its most essential aspects. The authors would also like to highlight that the current version of the summary represents a compromise between the expectations of the reviewers — on one hand, it was necessary to add certain information, while on the other, to reduce the overall length.

 

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

I believe the revision has greatly enhanced the overall quality of the manuscript, especially in terms of clarity and readability.

Reviewer 2 Report

Comments and Suggestions for Authors

The authurs pisitively responsed most of my concerns, there I suggest to accept this ms.