Water Surface Loss and Deforestation in the Brazilian Amazon Biome by Farming Expansion and Weak Legislation

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This manuscript explores the interactions between deforestation, water surface loss, and agricultural expansion in the Brazilian Amazon from 1985 to 2023, emphasizing the influence of weak or inconsistent environmental legislation. It tackles a timely and important sustainability issue. However, the current version needs to enhance the depth of analysis and address the impact of coarse spatial resolution. The specific suggestions are as follows.

(1) The authors examine how ecological changes respond to evolving policy environments. However, the analysis is only descriptive and requires deeper theoretical support. I advise integrating established frameworks from environmental governance or land-use change theory to clarify the links between legislative modifications and observed ecological patterns.

(2) While the Introduction covers Brazil's environmental policy history in detail, it lacks a structured review of the relationships between forest loss, water surface dynamics, and agricultural expansion.

(3) The description of the research methods is incomplete and not detailed enough. Additionally, Figure 2 should state the “Multivariable analysis” used.

(4) Relying solely on PCA and K-means clustering is inadequate for a 39-year, biome-wide environmental change analysis.

(5) The analysis is conducted at the entire Amazon biome level, which masks sub-regional variations in land-use change and policy enforcement.

(6) The discussion section is unstructured, with limited integration of ecological processes or implications.

Author Response

Reviewer 1

This manuscript explores the interactions between deforestation, water surface loss, and agricultural expansion in the Brazilian Amazon from 1985 to 2023, emphasizing the influence of weak or inconsistent environmental legislation. It tackles a timely and important sustainability issue. However, the current version needs to enhance the depth of analysis and address the impact of coarse spatial resolution. The specific suggestions are as follows.

(1) The authors examine how ecological changes respond to evolving policy environments. However, the analysis is only descriptive and requires deeper theoretical support. I advise integrating established frameworks from environmental governance or land-use change theory to clarify the links between legislative modifications and observed ecological patterns.

          R – We thank the reviewer for this valuable recommendation. The integration of established theoretical frameworks from environmental governance and land-use change theory has been thoroughly addressed and is now explicitly discussed in the revised manuscript [L. 4446–459].

(2) While the Introduction covers Brazil's environmental policy history in detail, it lacks a structured review of the relationships between forest loss, water surface dynamics, and agricultural expansion.

R – We thank the reviewer for this important suggestion. A structured review of the relationships between forest loss, water surface dynamics, and agricultural expansion has been added in the introduction of the revised manuscript, as recommended [L. 54–67].

(3) The description of the research methods is incomplete and not detailed enough. Additionally, Figure 2 should state the “Multivariable analysis” used.

R – Thank you for your helpful comment. We have expanded the methods description, revised Figure 2 to indicate the multivariable analysis used clearly, and clarified this point in the figure legend as well [L. 144–221].

(4) Relying solely on PCA and K-means clustering is inadequate for a 39-year, biome-wide environmental change analysis.

R – We thank the reviewer for their valuable comments and constructive criticism regarding the methodological choices in our manuscript. We fully recognize the complexity of analyzing nearly four decades of environmental change across the entire Amazon biome and agree that diverse analytical approaches can contribute to a more comprehensive understanding of such a vast system. However, we emphasize that our application of PCA-Factorial and K-means clustering is both methodologically robust and well-justified for the objectives of our study.

Principal Component Analysis (PCA) and K-means clustering are powerful exploratory tools for diagnosing environmental patterns in large, heterogeneous regions like the Amazon biome. PCA efficiently reduces the dimensionality of complex datasets by extracting principal components that summarize the joint behavior of highly correlated variables, as seen in the strong correlations between forest, pasture, agriculture, and water surface classes in our study. The high significance of Bartlett’s sphericity test (p < 0.05) confirmed the suitability of the correlation matrix for PCA, demonstrating that the variables shared substantial information, thus justifying dimensionality reduction. The extracted factors not only explained over 96% of the total variance but also distinguished temporal regimes of land use and hydrological change, highlighting both anthropogenic and climatic signals.

K-means clustering, applied to the PCA factor scores, enabled the objective grouping of years with similar land cover trajectories. The F test applied to cluster formation yielded extremely low p-values (p < 0.01), indicating that the between-group variability was significantly greater than within-group variability. This robust separation demonstrates that cluster analysis is a reliable method for segmenting periods with distinct environmental behaviors, such as years of forest and water conservation versus years dominated by pasture and agriculture expansion or affected by hydrological extremes like La Niña.

As reinforced by the literature, both PCA and K-means clustering are recommended as exploratory and diagnostic techniques in environmental sciences, especially for initial pattern recognition, hypothesis generation, and supporting decision-making at broad spatial and temporal scales. While it is true that additional inferential or causal models could complement the analysis, our use of these methods, together with rigorous significance testing, ensures that the key spatio-temporal structures and transitions in Amazonian land cover dynamics are robustly and transparently identified.

(5) The analysis is conducted at the entire Amazon biome level, which masks sub-regional variations in land-use change and policy enforcement.

R – We sincerely thank the reviewer for highlighting the issue of spatial heterogeneity within the Amazon biome and the risk that a biome-wide analysis may mask sub-regional variations in land-use change and policy enforcement. We fully recognize that the Amazon encompasses a wide range of ecological zones, land-use histories, and socio-political realities, from the so-called “Arc of Deforestation” in southern and eastern Amazonia to more remote or protected regions, each with distinct trajectories and pressures.

Our study adopted a biome-wide approach as an essential first step to detect the main temporal transitions, dominant trends, and system-wide responses to national policy shifts over nearly four decades. This scale is especially relevant for supporting national and international policy debates and for quantifying the cumulative impacts of broad legislative changes that often transcend state or municipal boundaries. Through robust multivariate techniques such as PCA and K-means clustering, we identified major temporal patterns and critical periods that impact the Amazon as a whole.

Nevertheless, we fully agree that future analyses should move toward finer spatial scales to capture spatial heterogeneity in policy enforcement, economic drivers, biophysical context, and local governance. For example, studies focusing on the Arc of Deforestation, conservation units, or indigenous lands can shed light on areas with exceptionally high or low deforestation rates and distinct responses to legislation. Incorporating spatially explicit data on enforcement actions (e.g., fines, inspections), land tenure, and infrastructure would further refine our understanding of land-use dynamics within the biome.

We have now emphasized this limitation in the conclusions of the manuscript and explicitly recommend that future work employ disaggregated approaches to unravel the diversity of land-use trajectories and policy outcomes across the Amazon biome [L. 726–737].

(6) The discussion section is unstructured, with limited integration of ecological processes or implications.

R – We thank the reviewer for their thoughtful and constructive feedback regarding the structure of our Discussion section. In response to your excellent suggestions, we have substantially reorganized this section into clear and logical subtopics, aiming to improve clarity and guide the reader through the multiple dimensions of our findings. The revised Discussion now comprises the following subitems:

4.1. Historical Evolution of Environmental Policies in the Amazon
4.2. Legislative Changes, Governance, and Land-Use Dynamics
4.3. Socio-Ecological Processes and Environmental Feedbacks
4.4. Policy Implications and Conservation Challenges
4.5. Ecological Feedbacks, Socio-Environmental Risks, and Future Pathways

We believe this new structure addresses your concerns and provides a more accessible and comprehensive discussion for readers. Thank you again for helping us strengthen our manuscript [L. 433–694].

Reviewer 2 Report

Comments and Suggestions for Authors

Although the work provides concrete data and an interesting regulatory review, the results and discussion fail to integrate these elements in a critical and coherent manner. To strengthen the discussion, it would be necessary to contrast the empirical results with key moments of legislative change and identify specific gaps in environmental regulation that explain the observed trends in the cause-effect relationship suggested by the title.      

Comments for author File: Comments.pdf

Author Response

Reviewer 2

Although the work provides concrete data and an interesting regulatory review, the results and discussion fail to integrate these elements in a critical and coherent manner. To strengthen the discussion, it would be necessary to contrast the empirical results with key moments of legislative change and identify specific gaps in environmental regulation that explain the observed trends in the cause-and-effect relationship suggested by the title.    

R – We sincerely thank Reviewer 2 for the careful reading and insightful suggestions regarding the integration of empirical results with the legislative timeline and regulatory gaps. All of your recommendations were entirely accepted and incorporated into the revised manuscript. Specifically, we added new paragraphs immediately after Figure 6 in Section 3.4 “Cluster analysis” [L. 422–432] and the second paragraph of Subsection 4.2 “Legislative Changes, Governance, and Land-Use Dynamics”, in the Discussion [L. 460–470]. These additions critically contrast the quantitative results with key legislative milestones, explicitly identify regulatory gaps, and clarify the cause-and-effect relationships between policy changes and environmental trends, as suggested by your comments. We appreciate your valuable feedback, which helped strengthen the coherence and analytical depth of our discussion.

Reviewer 3 Report

Comments and Suggestions for Authors

Summary

In this paper the authors describe an assessment the deforestation pressures on the Amazon basin in Brazil and the links to the country’s legislation. It traces the expansion of agriculture and the impact of poor legislation on deforestation. Using data from satellite imagery it quantifies the extent of the changes and their causes. In particular, it focuses on the role of the Government and of legislation on the Amazon.

Assessment

This is an important and significant paper on the extent of deforestation in the Amazon and its legislative causes.

The Introduction provides an excellent overview of the Amazon basin, its history, the loss of forest cover and its impact, and the role of legislation and environmental policy in its deforestation. Hosting the Earth Summit in Rio de Janeiro in 1992 was a high point but electoral changes since have eroded the country’s achievements.

Section 2, Methodological Approach, outlines the study area and its characteristics, the data sources and analytical tools.

Section 3, Results, presents the outcome from the research, firstly with a lengthy and comprehensive description of the legislation of the 1985 – 2023 period, a period marked by major swings in Government. Figure 3 provides a summary of these swings in the national government of Brazil. The second part of this section documents the changes in land cover and land use over the 38-year period of investigation, the significant decrease in forest cover and water surface expanse in the region.

It is unclear to me how the water surface area can change so much – do rivers and lakes vary widely in their extent? Figure 4a shows this variation, which is much greater than for the forest, pasture and agriculture.

The study applied Principal Component Analysis to identify the associations between components and then uses cluster analysis to define four factors which are shown on Figure 6 which is a particularly useful and clear diagram of these factors.

Section 4, Discussion, provides a lengthy and detailed historical analysis of the interaction of politics and the environment of the Amazon ending with suggestions for using the tax system and alternatives for sustainable socioeconomic development.

The paper’s Conclusions summarise the findings, identifies some limitations and notes that the country will host the 30^th COP for the Climate Change Convention in November, 2025.

The paper is very clear in its methods and findings, and the study would be reproducible given access to the data for which a link is provided. The discussion and conclusions are consistent with the findings. The strength of the paper lies in the overview it provides of the changes in land cover and land use in the Amazon.  Although some policy recommendations are provided, these could be expanded as its paucity of policy recommendations are a weakness.

There are many papers on deforestation in the Amazon, particularly focused on the biodiversity losses and the climate impacts of such change. The unique feature of this paper is that it links the deforestation to the legislation applicable over the past nearly 40 years.

The Figures and Tables are clear and legible throughout. The Figures in particular are excellent. The English is quite satisfactory. The authors declare no conflicts of interest. All but 7 of the 125 references are post 2000 and the references display a wide readership by the authors. Self -citation is not an issue.

Overall, an excellent paper, well researched and very well presented. Providing a comprehensive link between legislative policy and the environment the paper comprises an excellent resource.

Specific Comments

Line 113 “with more recent obstacles (between 2019 and 2022)” This is rather vague. Can you specify what are the obstacles for those readers who are not I Brazil.

Line 430 “[NO_PRINTED_FORM] [4]”??

Line 524 I could not find what IL stood for.

Line 610-1 “relaxation of forest protection rules, which may have encouraged deforestation.” Surely you can be stronger here.

Author Response

Reviewer 3

Comments and Suggestions for Authors

 Summary

In this paper the authors describe an assessment the deforestation pressures on the Amazon basin in Brazil and the links to the country’s legislation. It traces the expansion of agriculture and the impact of poor legislation on deforestation. Using data from satellite imagery it quantifies the extent of the changes and their causes. In particular, it focuses on the role of the Government and of legislation on the Amazon.

Assessment

This is an important and significant paper on the extent of deforestation in the Amazon and its legislative causes.

The Introduction provides an excellent overview of the Amazon basin, its history, the loss of forest cover and its impact, and the role of legislation and environmental policy in its deforestation. Hosting the Earth Summit in Rio de Janeiro in 1992 was a high point but electoral changes since have eroded the country’s achievements.

Section 2, Methodological Approach, outlines the study area and its characteristics, the data sources and analytical tools.

Section 3, Results, presents the outcome from the research, firstly with a lengthy and comprehensive description of the legislation of the 1985–2023 period, a period marked by major swings in Government. Figure 3 provides a summary of these swings in the national government of Brazil. The second part of this section documents the changes in land cover and land use over the 38-year period of investigation, the significant decrease in forest cover and water surface expanse in the region.

It is unclear to me how the water surface area can change so Much–do rivers and lakes vary widely in their extent? Figure 4a shows this variation, which is much greater than for the forest, pasture, and agriculture.

R – We thank the reviewer for highlighting the need to clarify the high interannual variability in water surface area observed in Figure 4a. In the revised manuscript, we have addressed this point in three key locations:

1) Introduction - we include the fundamental links between deforestation, changes in water surface extent, and agricultural expansion, explicitly mentioning how forest loss disrupts the hydrological cycle and affects both precipitation and runoff in the Amazon [L. 124–132].

2) Section 3.2. - we provide a detailed explanation that the pronounced variation in water surface area, as seen in Figure 4a, is a result of the Amazon’s highly dynamic flood pulse regime. This regime is influenced not only by seasonal and interannual climate variability, such as El Niño and La Niña events, but also by anthropogenic drivers, including deforestation, dam construction, and increased sedimentation [L. 324–334].

3) Legend of Figure 4 - was updated to state that the pronounced variability in water surface reflects the Amazon’s natural flood pulse regime, as well as the influence of climate extremes and land use change [L. 339–342].

The study applied Principal Component Analysis to identify the associations between components and then uses cluster analysis to define four factors which are shown on Figure 6 which is a particularly useful and clear diagram of these factors.

Section 4, Discussion, provides a lengthy and detailed historical analysis of the interaction of politics and the environment of the Amazon ending with suggestions for using the tax system and alternatives for sustainable socioeconomic development.

The paper’s Conclusions summarise the findings, identifies some limitations and notes that the country will host the 30^th COP for the Climate Change Convention in November, 2025.

The paper is very clear in its methods and findings, and the study would be reproducible given access to the data for which a link is provided. The discussion and conclusions are consistent with the findings. The strength of the paper lies in the overview it provides of the changes in land cover and land use in the Amazon.  Although some policy recommendations are provided, these could be expanded as its paucity of policy recommendations are a weakness.

There are many papers on deforestation in the Amazon, particularly focused on the biodiversity losses and the climate impacts of such change. The unique feature of this paper is that it links the deforestation to the legislation applicable over the past nearly 40 years.

The Figures and Tables are clear and legible throughout. The Figures in particular are excellent. The English is quite satisfactory. The authors declare no conflicts of interest. All but 7 of the 125 references are post 2000 and the references display a wide readership by the authors. Self -citation is not an issue.

Overall, an excellent paper, well researched and very well presented. Providing a comprehensive link between legislative policy and the environment the paper comprises an excellent resource.

Specific Comments

4) Line 113 “with more recent obstacles (between 2019 and 2022)” This is rather vague. Can you specify what are the obstacles for those readers who are not I Brazil.

R – (Done). An explicit version mentioning the Bolsonaro government was added [L. 128].

5) Line 430 “[NO_PRINTED_FORM] [4]”??

R – (Done). The “[NO_PRINTED_FORM] [4]” was an error by Mendeley. We corrected [L. 524].

6) Line 524, I could not find what IL stood for.

R – (Done). We thank the reviewer for pointing out the need for clarification regarding the acronym "IL." We confirm that "IL" stands for "Indigenous Lands," as described in the revised manuscript within Subsection 4.2, "Legislative Changes, Governance, and Land-Use Dynamics." The term is now defined at its first occurrence to ensure clarity for all readers [L. 509].

7) Line 610-1 “relaxation of forest protection rules, which may have encouraged deforestation.” Surely you can be stronger here.

R–(Done). We thank the reviewer for this excellent suggestion. The recommended change has been fully incorporated into the “5. Conclusions” of the revised manuscript [L. 708–716].

Reviewer 4 Report

Comments and Suggestions for Authors

Dear authors,

Please find the comments of my review, in the attached document.

Best regards

Comments for author File: Comments.pdf

Author Response

Reviewer 4

Overall conclusion: Reject

General comments:

The study is rather interesting, considering thewidely spread impact (at global scale) of the Amazonian region, and its’ changes

I do not consider the results of this study to be groundbreaking

English language requires some minor improvements

What usefulness or relevance would this study have applicable in real-world scenarios? Considering all the laws you have mentioned, which ones had the best results, and what other potential (legislative) measures would you propose, based on the scientific results, you have provided

The methodological chapter is insufficiently addressed/presented

Despite the title addressing the legislative aspect, perhaps too muchdescriptiveemphasis has been given to the political aspect, considering this is a scientific journal in the geo-spatial field

I find this entire manuscript confusing in regards to its main objectives, with a confusing mix of geo-spatial, statistical and legislative approaches

Not enough emphasis was given to the deforestation process, and validation is lacking completely

R – We thank the reviewer for their careful reading and detailed comments on our manuscript. We would like to emphasize that we are fortunate to conduct our research in a country where academic freedom is respected, and a diversity of perspectives, including ideological ones, can be expressed, provided that they are grounded in robust scientific evidence. All the analyses and interpretations presented in this study are based on empirical data, internationally recognized methodologies, and a critical review of the scientific literature. The manuscript explicitly demonstrates these scientific foundations, ensuring that data and rigorous analysis transparently support our arguments regarding legislative and political drivers. We believe this plural and evidence-based approach enriches the scientific debate and supports informed discussion on the future of the Amazon biome.

In the following sections, we address each of the reviewer’s specific and general comments, including those related to methodology, graphical presentation, the structure of the results and discussion, and the scientific relevance and validation of our findings.

 Specific Comments:

L116 – “relationship” is an obvious aspect to say, but causation-correlation is the more important aspect to be literally addressing. Please consider rephrasing.

R – We thank the reviewer for this important observation. The point regarding the distinction between correlation and causation has been well-received and is now explicitly addressed in the revised manuscript. The clarification has been incorporated into the Introduction [L. 133–142].

2) Figure 1 – please describe in more detail the extents/boundaries of the Brazilian biome, and the official geo-spatial(GIS) limits that you have used, as well as any potential alternatives, along with the arguments for using them.

R – Thank you for your thoughtful feedback. In response to your suggestions and those of the other reviewers, we have substantially expanded and clarified the Methodology section. These improvements have enhanced the rigor, transparency, and overall quality of the manuscript [L. 144–221].

3) Figure 2 is insufficiently developed, and honestly, looks rather primitive. This does not necessarily emphasize a scientifically-sound approach

R – Thank you for your constructive comment regarding Figure 2. We would like to clarify that this figure is intended solely as a summary of the overall workflow, rather than a detailed methodological diagram. In response to your suggestion, we remade the “Decision Process” and the figure legend to clarify which statistical techniques were used in each step. We appreciate your feedback, which helped us improve the clarity and scientific rigor of this section [L. 218–221].

4) Contemporaneous legislation (chapter 3.1) should not be in the Results Chapter, but rather, in the Introductory chapter, or perhaps structured differently, because it does not address your personal results, but rather, a summarization of the aforementioned laws.

R – We thank the reviewer for this observation. The placement of "Contemporaneous Brazilian legislation (chapter 3.1)" was originally considered for the Introduction, as it indeed provides important legal and historical context. However, because the survey of the environmental legislation throughout the analyzed period forms a central part of our research object, and given our aim to analyze the interaction between legislative changes, the political composition of Congress and the presidency; and the resulting trends in deforestation, water scarcity, and agribusiness expansion, we opted to integrate this content within the Results section. Additionally, the substantial length and detail required for this legislative review contributed to our deciosn (to keep this part in the Results section, as including it in the Introduction could have disrupted the flow and focus of that section.

This structure enables a more direct and critical discussion of how specific legislative acts, approved under different political majorities, are temporally and causally associated with observed land-use and hydrological changes in the Amazon. By aligning the legislation summary with our analytical results, we can better explore the cause-and-effect relationships at the core of the manuscript and provide readers with a coherent interpretation of the data within its evolving political and legal context.

We appreciate your feedback, which has helped us clarify and justify our structural choices.

5) Figure 4 is poorly made – low readability, lack of measurement units etc.

R – Thank you for your helpful feedback regarding Figure 4. In response to your suggestions, we have revised the figure to improve its readability and overall clarity. Additionally, the measurement units for each variable are now explicitly described in the figure legend. We appreciate your comments, which contributed to enhancing the quality and presentation of our results [L. 339–342].

6) Figure 6 is also poorly made.

          R – Thank you for your comment regarding Figure 6. We acknowledge that the figure in the manuscript serves primarily as a static illustration. Due to the large amount of data presented, it is almost impossible to avoid some overlap in a static figure. For this reason, as described in our "Data Availability Statement: Database https://doi.org/10.5281/zenodo.15787966", we have made all scripts available, including the one that generates an interactive version of Figure 6, which can be opened in any web browser. This interactive tool allows users to zoom in, zoom out, hover over labels, and examine details with much greater clarity and flexibility. We believe this approach substantially enhances both the transparency and reproducibility of our results. Thank you for the opportunity to clarify this point.

7) L358-362: I find it rather confusing to state these graphical results, as confirming generally valid truths. This paragraph should be much more detailed, in describing specific findings, not just generally available truths.

R – We appreciate your feedback on this section. So, we would like to emphasize that the results presented in the manuscript are derived directly from the data, with no subjective interpretation or bias. Our approach focused on transforming a large and complex dataset into concise and clear information using robust statistical and graphical techniques. We do not seek to state general “truths,” but rather to objectively highlight the empirical patterns and temporal shifts that emerge from the data analysis. The findings, including the clustering of periods with distinctive land use and hydrological profiles, are a direct product of the statistical associations revealed by the multivariate analyses, and not of any preconception or subjective assessment by the authors.

Nevertheless, we have revised and expanded this paragraph in the Results section to provide a more detailed description of the specific findings and the data-driven evidence underlying our interpretations. Thank you for your comments, which have helped us further clarify the objectivity and transparency of our results [L. 422–432].

8) L430 –No printed form? What is this? A formatting error?

          R – (Done). Was an error by the Mendeley software [L. 524]. Thank you.

9) The Discussion chapter is descriptive, but not necessarily relevant in describing the results.

          R – Thank you for your valuable feedback. In response to your suggestions, as well as those from the other reviewers, we have restructured the Discussion and added new paragraphs throughout the section to strengthen the direct connection between our results and their interpretation. These changes aim to ensure that the Discussion is more focused, analytical, and closely aligned with the empirical findings presented in the manuscript [L. 433–694]. 

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

Following the authors’ revisions, the manuscript has improved in the description of methods and in the organization of the discussion section, and it has addressed most of the comments raised in the first review. The topic remains highly relevant, focusing on the interplay between ecological change and policy in the Amazon, and the study offers potential contributions to the literature. Nevertheless, there are still important issues that need further improvement, particularly with respect to formatting quality, the lack of sub-regional analysis, and the depth and integration of the discussion.

First, the overall presentation is still not satisfactory. The manuscript would benefit from careful editing to meet the journal’s formatting standards and to improve readability.

Second, the issue of spatial heterogeneity is acknowledged in the revised version, but the response is not sufficient. The current draft mainly emphasizes this as a limitation for future work, without providing any additional analysis. To make the results more convincing, the manuscript should include at least a partial examination of sub-regional variation. Even if presented in supplementary material or through simple descriptive statistics, would already add substantial value.

Third, although the discussion is now divided into subsections, the links between these parts remain weak. Much of the text repeats the results instead of exploring the ecological and governance mechanisms in greater depth. The discussion should provide stronger integration across subsections and a more critical interpretation of how environmental processes and policy interact.

Author Response

Reviewer 1

Following the authors’ revisions, the manuscript has improved in the description of methods and in the organization of the discussion section, and it has addressed most of the comments raised in the first review. The topic remains highly relevant, focusing on the interplay between ecological change and policy in the Amazon, and the study offers potential contributions to the literature. Nevertheless, there are still important issues that need further improvement, particularly with respect to formatting quality, the lack of sub-regional analysis, and the depth and integration of the discussion.

First, the overall presentation is still not satisfactory. The manuscript would benefit from careful editing to meet the journal’s formatting standards and to improve readability.

R – We thank the reviewer for this valuable observation. In response, the manuscript has been carefully revised to improve clarity, readability, and alignment with the journal’s formatting standards. Specific improvements include:

• Title: modified to adopt a more neutral and academic wording, avoiding strong or politically biased expressions.
• Abstract and Introduction: edited for conciseness and improved flow, avoiding redundancies and ensuring a more straightforward presentation of objectives and findings.
• Consistency in terminology: terms such as agriculture, pasture, water surface loss, and deforestation were standardized throughout the text.
• Figures and Tables: captions were revised for clarity and to comply with journal style; units and abbreviations were standardized.
• English language and academic style: the text was carefully edited to avoid colloquial or journalistic expressions, adopting a more formal and scientific tone.
• Section structure: subsections were better organized (e.g., Methods and Discussion), facilitating logical progression and readability.
• References: updated formatting to ensure full compliance with MDPI guidelines.

We believe these edits, including the adjustment of the title to a more neutral language, significantly enhanced the overall presentation of the manuscript and fully addressed the reviewer’s concern.

Second, the issue of spatial heterogeneity is acknowledged in the revised version, but the response is not sufficient. The current draft mainly emphasizes this as a limitation for future work, without providing any additional analysis. To make the results more convincing, the manuscript should include at least a partial examination of sub-regional variation. Even if presented in supplementary material or through simple descriptive statistics, would already add substantial value.

R – We thank the reviewer for this important observation. Our study was designed to emphasize the role of federal legislation in shaping land-use and water dynamics across the Amazon biome as a whole. This national-level perspective is central, as environmental laws in Brazil are defined and enforced primarily at the federal level, and considering the main characteristics of different Brazilian biomes, not internal regionalizations.

Nevertheless, we agree that highlighting sub-regional variation adds value. Throughout the manuscript, we explicitly reference critical areas such as the Arc of Deforestation, which encompasses parts of Mato Grosso, Rondônia, eastern Acre, southern Pará, Tocantins, and Maranhão, including the Upper Xingu Basin. These frontier states are disproportionately affected by agricultural expansion, deforestation, and water surface reduction, reflecting the uneven impacts of land-use change across the biome. By contrast, other regions such as Amazonas and Amapá still retain larger portions of preserved forest and water resources (so far).

To further strengthen our discussion, we incorporated recent evidence from Franco et al. (2025, Nature Communications), which demonstrates that deforestation for farming purposes not only contributes to important forest loss but also reduces rainfall and intensifies dry-season warming in the Amazon. This reinforces that biome-based studies are highly relevant for understanding the problem, as local land-use dynamics can amplify climate-driven processes and directly affect water surface reduction [L. 582–587].

We emphasize, however, that such sub-regional analyses are most effective when grounded in biome-scale approaches, which provide the necessary baseline for comparison and contextualization. For this reason, our study focuses on the Amazon biome as a whole, while recognizing that future work should deepen these analyses at finer spatial resolutions to capture more localized patterns of heterogeneity.

We believe this approach strengthens the manuscript by clarifying that, while our primary focus is on federal legislative impacts at the biome scale, the analysis acknowledges sub-regional dynamics and integrates recent evidence that supports their importance [e.g., L. 550–555].

Third, although the discussion is now divided into subsections, the links between these parts remain weak. Much of the text repeats the results instead of exploring the ecological and governance mechanisms in greater depth. The discussion should provide stronger integration across subsections and a more critical interpretation of how environmental processes and policy interact.

R – We thank the reviewer for this constructive comment. The subdivision of the Discussion section into subsections was introduced in response to requests from other reviewers, who suggested a clearer organization of themes to facilitate readability. In reviewing the manuscript, we sought to “bind together” these subsections as much as possible, ensuring fluid transitions and avoiding redundancy with the Results.

Rather than replicating findings, each subsection was structured to focus on a specific dimension of the study: the proposals and setbacks of environmental legislation over the analyzed period; the relationship between these legislative shifts and land-use change (shaped in large part by the composition of the National Congress); the socio-ecological processes and their environmental feedbacks; the political implications and conservation challenges; and the socio-environmental risks and future pathways.

This structure allows for greater depth in analyzing the interplay between governance and ecological processes while maintaining coherence across the text. We believe that this approach strengthens the critical interpretation of how environmental policies and socio-ecological dynamics interact in the Amazon biome.

Reviewer 2 Report

Comments and Suggestions for Authors

no comments

Author Response

Thank you.

Reviewer 4 Report

Comments and Suggestions for Authors

Dear authors,

Thank you for submitting your updated manuscript. Unfortunately, the main issue of this topic has remained the same and I do not consider it to be groundbreaking, or sufficiently relevant enough, through its' findings to be published in Earth Journal, MDPI.

Best regards

Author Response

Thank you.

Round 3

Reviewer 1 Report

Comments and Suggestions for Authors

It can be considered for acceptance.

Author Response

Thank you.