Assessing Forest Degradation Through Remote Sensing in the Brazilian Amazon: Implications and Perspectives for Sustainable Forest Management

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Review Report for Manuscript ID remotesensing-3294290-peer-review-v1: "Anthropogenic Amazon Forest Disturbances through Remote Sensing: Analysis and Perspectives for Sustainable Forest Management"

 

Brief Summary

The article presents a comprehensive literature review on Amazon forest degradation, disturbances, and Sustainable Forest Management. It examines various remote sensing methods used to identify and monitor forest degradation, primarily focusing on selective logging. By analyzing 80 articles, the authors aim to map trends, discuss gaps in research, and highlight methodological approaches in remote sensing that contribute to forest monitoring.

 

Strengths:

• Relevance: The topic is relevant, given the ongoing need to monitor and manage Amazonian forests and address the environmental impact of degradation.
• Scope: By including a range of data sources and methodological approaches, the article aims to provide a broad perspective on Amazonian forest monitoring.

 

Limitations:

• Lack of Novelty: The article is structured as a literature survey without introducing original perspectives or conducting a deeper comparative analysis, which limits its contribution to advancing current knowledge.
• Ambiguity in Key Concepts: Terms like “forest degradation” and “disturbance” are used interchangeably, creating confusion around the article's central concepts.

General Concept Comments

Concept Clarity and Terminology Consistency

·       Relevance of Terminology: The title references “disturbances,” a term with clearer ecological implications. However, the body of the article predominantly centers on “degradation,” which the authors describe using various ambiguous definitions, making it challenging to follow a consistent theme. Focusing on disturbances—selective logging, fire, and other definable impacts—might yield a more cohesive structure and align with the field’s standards. Consistent terminology throughout the manuscript is essential for clarity and coherence.

Methodology and Review Structure

·       Scope of the Review: The selection of studies spans from 2003 to 2024 but does not systematically analyze the evolution of remote sensing methods over this time. This broad timeframe, combined with a simple count of studies, offers little insight into how methodologies have advanced or which technologies have proven most effective. A more segmented analysis by time periods or methodological trends could yield more relevant conclusions and enhance the review's value.

·       Lack of Meta-Analysis: The review lists methods and techniques without conducting any meta-analytical evaluation to assess their effectiveness. A meta-analysis could provide quantifiable insights into which remote sensing techniques most reliably detect Amazonian forest degradation. The lack of this deeper statistical analysis limits the article's impact.

Contribution to Knowledge and Perspective

·       Contribution to the Field: As it stands, the article lacks a critical focus and does not provide a compelling case for how the findings could guide future research. Narrowing the review to a focused question (e.g., efficacy of specific remote sensing technologies for selective logging) and then evaluating the approaches’ strengths and limitations would enhance the article’s contribution to the field.

 

Specific Comments on Structure, Figures, and Tables

Lines 57-59: The term “Reduced Impact Logging” is introduced without definition. For clarity, the first mention of technical terms should be accompanied by definitions, especially if they are key concepts.

Line 80: Seven citations are listed for a single concept, which feels excessive. The article could be streamlined by choosing the most recent and relevant references.

Lines 86-87: Discussing Landsat’s sensitivity to detecting forest canopy changes may not be essential in the introduction. This detail could be saved for a section on remote sensing limitations.

Lines 95-96: The authors state that high-resolution images are necessary for detecting disturbances without discussing their cost-effectiveness. Addressing a cost-benefit analysis of high-resolution imagery for large areas like the Amazon would enhance this argument's robustness.

Line 99: The acronym “LiDAR” should be defined upon its first use to avoid confusion.

Section 1.3 (Lines 107-164): The discussion around “forest degradation” is lengthy and ambiguous. This section would benefit from concise definitions that align with the broader ecological concepts. If “disturbances” are more measurable, focusing on them might help streamline the review and make it more actionable for readers.

Figure 1 (Line 152): The figure is not self-explanatory, and there are mistakes, such as “Florest” instead of “Forest.” Additionally, the visual does not clearly support the concept it aims to define. A revised or simplified figure might better support this section.

Line 183: The difference between “Reduced Impact Logging” (RIL) and “Sustainable Forest Management” (SFM) remains unclear. Specific examples to illustrate this distinction would be beneficial.

Line 204: The acronym “UT” is used without definition. All acronyms should be explained at first mention for clarity.

Figure 2: The purpose of sub-figure “2C” is unclear, and the figure legend is insufficiently detailed. A more explicit legend and the removal of redundant elements would improve its clarity.

Lines 227-242: The section on “types of disturbances” is insightful and might offer a more useful framing than “forest degradation.” Concentrating on these types as a focal point for the review would likely strengthen the article.

Materials and Methods 

Line 262: The abbreviation “SR” appears unexplained. If referring to “Remote Sensing,” the standard abbreviation is “RS.” Clarifying this abbreviation would avoid confusion.

Figure 5: The word cloud is not particularly informative for the analysis. Consider replacing it with a thematic analysis or citation trends, which may add more analytical value.

Figure 6: Sample sizes within each disturbance category are insufficient for robust inferences. Either expanding these categories or removing this figure would strengthen the review’s conclusions.

Figure 7: The figure lacks adequate explanation, and the legend does not clarify the colors and numbers shown. This figure needs additional information to be understandable and self-contained.

Figure 9: The class separation appears unbalanced, which limits interpretive value. Grouping the classes or adding more balanced data could increase the utility of this figure.

 

Discussion and Conclusions: 

The final section lacks reflections that might guide future research or inform forest management policies. Including specific recommendations based on the review’s findings would greatly improve this section.

Comments for author File: Comments.pdf

Author Response

"Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

I commend the authors on their efforts for this manuscript.  I appreciate their structured review of the topic.  I have two minor comments.

The first sentence of section 1.3 about clearcuts seems to be out of place in a section about partial cuts.  I suggest the authors consider omitting it.

Regarding the information presented in lines 194 – 220: I was difficult for me to understand  the thought or comparison the authors were trying to convey in these paragraphs and in figures 2 and 3.  It might be more effective to combine figures 2 and 3 and present these graphics as one figure which might enhance the reader's ability to contrast these two approaches.

 

Author Response

Dear Reviewer,

Thank you very much for taking the time to review this manuscript. We appreciate the time and effort that you have dedicated to providing your valuable feedback on the manuscript. We are grateful to the reviewers for their insightful comments on the paper. We have been incorporate changes to reflect all of the suggestions provided by the reviewer. We have highlighted (in turquoise) the changes within the manuscript. Please find the detailed responses below and the corresponding revisions/corrections highlighted in the re-submitted files.

General comments

Comment 1: I commend the authors on their efforts for this manuscript.  I appreciate their structured review of the topic.  I have two minor comments.

Response 1: Dear reviewer, we are immensely grateful for your observation and for recognizing our efforts to deliver quality work to society and the scientific community.

_____________________________________________________________

Point-by-point response to Comments and Suggestions for Authors

Comment 1: The first sentence of section 1.3 about clearcuts seems to be out of place in a section about partial cuts.  I suggest the authors consider omitting it.

Response 1:  Dear reviewer, thank you for your pertinent observation. We have omitted the section on clear-cutting from the text, which has made this section more focused on partial cuts. (see L117).

 

Comment 2: Regarding the information presented in lines 194 – 220: I was difficult for me to understand  the thought or comparison the authors were trying to convey in these paragraphs and in figures 2 and 3.  It might be more effective to combine figures 2 and 3 and present these graphics as one figure which might enhance the reader's ability to contrast these two approaches.

Response 2:  Thank you for the suggestion to combine the figures 2 and 3, it has substantially improved understanding the session. Figures 2 and 3 were combined to make the explanation about the differences between the systems more concise (seeL219). To adjust the discussions, we rewrote the texts that addressed the detection systems (see L211-217).

Reviewer 3 Report

Comments and Suggestions for Authors

In relation to temporary removal of standing trees due to human intervention, deforestation and forest degradation should be clearly distinguished. As the author is aware, the definition of forest degradation has not yet been scientifically established, but it is judged that it is not reasonable to affect planned and legal timber harvesting due to this.

Forest lands should be managed by dividing them into managed and unmanaged forests, and planned timber harvesting in managed forests should be considered as a renewable resource that can replace fossil fuels.

Detecting land cover changes based on satellite imagery is a very useful method in terms of time and space, but efforts are needed to improve accuracy, and detecting forest degradation requires more detailed observations (diversity, health, resilience, etc.) and longer-term monitoring.

The government needs to develop guidelines for selective logging that does not reach forest degradation, and these should take into account differences depending on forest conditions, management goals, tree species, etc.

Author Response

Dear Reviewer,

Thank you very much for taking the time to review this manuscript. We appreciate the time and effort that you have dedicated to providing your valuable feedback on the manuscript. We are grateful to the reviewers for their insightful comments on the paper.

Response 1:  Dear reviewer, we are immensely pleased that you have understood the core of our work so deeply. Given the importance of forest management for sustainable development, it is essential to differentiate the types of changes that can occur in the forest canopy, and especially to dissociate Sustainable Forest Management (SFM) from forest degradation.

 

Reviewer 4 Report

Comments and Suggestions for Authors

This article provides a comprehensive literature review on remote sensing monitoring of anthropogenic forest disturbances in the Amazon region. The research topic is highly important and timely, as forest degradation and sustainable forest management are current hot topics. The article is well-structured and content-rich, providing readers with a comprehensive overview of research in this field. However, there are still some aspects that can be further improved to enhance the quality and impact of the manuscript.

1.         Materials and Methods:

(1) Explain why 2003 was chosen as the starting year. What is the basis for this choice?

2.         Results:

(2) The trend line in Figure 4 could be determined using statistical methods (such as linear regression) rather than simple visual fitting.

(3) For the word cloud analysis in Figure 5, it is suggested to use more sophisticated text analysis techniques, such as topic modeling or semantic network analysis, to reveal deeper thematic structures.

(4) Figure 7 could be improved by using different colors or patterns to distinguish different types of forest disturbances, thereby increasing readability.

3.         Discussion:

(5) The hierarchical structure is not clear. It is suggested to add secondary headings and split into multiple sections.

(6) Suggest a more in-depth discussion of why most studies are concentrated in the "arc of deforestation" area, and the potential biases this concentration might bring.

(7) The potential and limitations of high-resolution images and advanced technologies (such as LiDAR) in monitoring forest degradation could be discussed in more detail.

(8) Suggest discussing how climate change might affect future forest degradation patterns and monitoring strategies.

4.         Conclusions

(9) Future research directions could be more clearly pointed out, especially in terms of improving forest degradation definitions and monitoring methods.

5.         References

(10) Check the consistency of reference formats.

6.         Others:

Consider adding a chart at the beginning of the article to outline the structure and main findings, helping readers quickly grasp the content of the article.

Author Response

Please see the attachment

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

In the manuscript titled “Anthropogenic Amazon Forest Disturbances through Remote Sensing: Analysis and Perspectives for Sustainable Forest Management”,  the authors have made some adjustments following my initial review, especially in terms of figure clarity and an expanded discussion. However, several areas of concern remain, notably regarding the clarity of key concepts, consistency of terminology, and practical applicability of the analysis. While the manuscript discusses the relevance of differentiating degradation and disturbance, the application of this distinction remains insufficiently defined throughout the text, impacting the clarity and coherence of the analysis. Below is a breakdown of what has been satisfactorily addressed, partially addressed, and not yet sufficiently addressed.

 

General Comments

1. Improvements Made

• Figure 1 Revision: The authors have revised Figure 1, making it more self-explanatory and visually distinct. This has improved clarity in illustrating the relationship between degradation and forest management practices, helping to highlight the conceptual distinctions between degradation and disturbances.
• Cost-Benefit Analysis: The manuscript now includes a section discussing the cost-benefit of using high-resolution imagery for monitoring the Amazon (pg. 12, lines 104-106; Discussion, lines 574-639). This addition provides valuable context for the practical challenges of large-scale monitoring and enhances the discussion of remote sensing tools.
• Structure and Labeling of Figures: Figures have been generally improved to be more self-contained, with additional labels and clarifications in the legends. This enhances the reader’s ability to understand the concepts without constantly referring back to the main text. Figures 1 and 2 in particular show notable improvement.

2. Partially Addressed Points

• Terminology Consistency: While the authors have updated the title to use "disturbance" rather than "degradation," the focus of the manuscript continues to be primarily on degradation. Sections such as 1.3 (pg. 5, lines 116-129) still predominantly discuss degradation without integrating disturbances as a distinct concept, which reduces the impact of the title change. This focus on degradation may create confusion for readers expecting an analysis centered on disturbances as indicated in the title.
• Temporal and Technological Evolution: The authors include a brief discussion of the evolution of monitoring methods (pg. 10, lines 322-330), but there is no structured analysis by time period. The addition of segmented time frames—such as early remote sensing developments, adoption of new satellite technologies, and the recent introduction of machine learning—could offer readers a clearer picture of methodological advancements.
• Abstract Adaptation: Although the title and some content have been modified, the abstract remains completely unchanged. It would benefit from reflecting the new focus on distinguishing between degradation and disturbances, summarizing key findings from the updated sections to give readers a more accurate summary of the revised content.

3. Points Not Adequately Addressed

• Conceptual Clarity in Degradation vs. Disturbance: The distinction between degradation and disturbance is still inconsistent. Although Figure 1 now visually represents this difference well, the narrative sections (e.g., Introduction, pg. 4-5, lines 107-143) continue to use these terms interchangeably or ambiguously. The text should consistently define and apply these terms, particularly in sections discussing legal logging and sustainable forest management.
• Practical Application of Findings: The discussion section could benefit from more explicit guidance on how these findings could inform future research or forest management practices. Specific recommendations on methodologies, remote sensing techniques, and practical applications would enhance the value of this research for decision-makers.
• Graphical Abstract: The graphical abstract is overly simplistic and does not effectively convey the manuscript's scope or findings. A more detailed graphic could better summarize the study’s core contributions, providing value to potential readers.

 

Specific Comments

Title and Abstract

• Title Consistency: While the title now uses "disturbances," the paper remains largely focused on degradation. For coherence, the manuscript needs a more balanced focus between both concepts or should revert to a title emphasizing degradation if this remains the primary focus.
• Abstract Revision: The abstract should be revised to align with the new emphasis on disturbances. Currently, it fails to reflect recent modifications, and readers might find it misleading given the manuscript's expanded scope.

Introduction

• Terminology in Section 1.3 (pg. 5, lines 116-129): This section discusses forest degradation in general terms but does not adequately introduce or differentiate disturbances. Introducing “disturbances” as a distinct concept here would create a clearer thematic structure.
• Figure 1 (pg. 5, lines 107-143): While the figure itself is clearer, the corresponding text could better differentiate degradation and disturbance. Explicitly referring to Figure 1 in the narrative to explain the distinction could strengthen the impact.

Figures and Tables

• Figure 1: Substantially improved in terms of clarity and visual quality. The authors effectively addressed earlier concerns by adding distinct labels and correcting language issues. This figure now better conveys the differences between degradation, deforestation, and conservation practices.
• Figure 2: This figure is generally clear and well-structured; I consider it acceptable in its current state, although some additional context in the legend could help readers unfamiliar with the topic.

Discussion

• Evolution of Monitoring Approaches (pg. 10, lines 322-330): The current discussion briefly mentions technological developments but would benefit from a segmented approach that organizes advances into defined time periods. For instance, delineating phases of technological advancement could better illustrate the evolution from medium-resolution satellite data to high-resolution tools and recent machine learning applications.
• Comparative Analysis of Methods (pg. 12-13): The discussion lacks a comparative evaluation of remote sensing techniques used to monitor low-intensity disturbances. Including an analysis of the efficacy, limitations, and practical applications of tools like LiDAR, NDVI, and nanosatellites would enhance this section and give readers a clearer understanding of the suitability of different methods.

Specific Terminology and Definitions

• Degradation vs. Disturbance: Throughout the manuscript, terms such as "degradation," "disturbance," and "forest management" are often used interchangeably. Clarifying these distinctions in sections such as 1.3 (pg. 5, lines 116-129) and 2.2 (pg. 7, lines 253-260) would add conceptual clarity and ensure consistency.
• Examples and Clarifications in Section 1.1: The authors might consider adding concrete examples in the introduction to illustrate differences between sustainable logging practices and degradation. This would provide readers with practical context to better understand the theoretical distinctions discussed.

Graphical Abstract

• Graphical Abstract: The current graphical abstract lacks detail and fails to capture the study's main contributions. It could be restructured to illustrate key concepts such as types of disturbances, the role of remote sensing, or a visual comparison of different monitoring methods to better inform potential readers about the content.

 

 

In summary, the manuscript has improved in terms of figure clarity, structural organization, and discussion of cost-benefit aspects. However, there are still notable gaps in the distinction between degradation and disturbance, the applicability of findings, and temporal structuring in the analysis of technological evolution. A revised focus on disturbances, a segmented discussion on technology advances, and a more robust comparative analysis of remote sensing methods would greatly enhance the manuscript’s contribution to the field.

Comments for author File: Comments.pdf

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 3

Reviewer 1 Report

Comments and Suggestions for Authors

Review Report

Title of the manuscript: "Assessing Forest Degradation through Remote Sensing in the Brazilian Amazon: Implications and Perspectives for Sustainable Forest Management"

 

General Comments:

The manuscript has significantly improved in this third version. The new title better aligns with the content, and there are clear advancements in the abstract, graphical abstract, and introduction. The authors have also made meaningful efforts to refine key conceptual distinctions and deepen the discussion. Below, I outline the key improvements and provide some additional suggestions.

 

Highlights of Improvements

1. Title: The revised title captures the focus of the manuscript much better and provides a clearer summary of its scope
2. Abstract and Graphical Abstract: Both have seen notable improvements. The abstract now provides a more accurate and concise summary of the manuscript, while the graphical abstract better communicates the study's contributions.
3. Introduction: The introduction has been refined, offering greater clarity in the explanation of key concepts like Sustainable Forest Management (SFM), Reduced Impact Logging (RIL), and Conventional Logging (CL). Their relationship with disturbances, degradation, and legal logging is also better articulated.
4. Definitions in Section 1.3: This section has been improved, with clearer definitions of forest degradation and disturbances. The effort to distinguish these terms is evident and appreciated.
5. Figure Captions: The captions for Figures 1 and 2 are more detailed and informative, which significantly enhances the reader's understanding of the visuals.
6. Discussion: The discussion section now includes a more detailed analysis of the REDD+ program’s impact and the role of legal disturbances in sustainable forest management. While this is a step forward, there are still two areas that could be expanded further (though this is not essential):
• A clearer segmentation of technological advancements over time to help readers understand key phases in forest monitoring development.
• A more detailed discussion of remote sensing techniques (e.g., NDVI, LiDAR), including their strengths, limitations, and practical applications.

 

Recommendations

1. Technological Evolution: Consider structuring the discussion on technological advancements into clear phases (e.g., medium-resolution satellite data, high-resolution tools, and machine learning applications). This would provide a more comprehensive perspective on the evolution of forest monitoring technologies.
2. Comparative Analysis of Methods: A comparative evaluation of the remote sensing techniques mentioned in the manuscript, with a focus on their efficacy, limitations, and use cases, would add further value to the discussion

Comments for author File: Comments.pdf

Author Response

Please see the attachment.

Author Response File: Author Response.pdf