Balance of Anthropogenic and Natural Greenhouse Gas Fluxes of All Inland Ecosystems of the Russian Federation and the Contribution of Sequestration in Forests

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This manuscript presents a comprehensive assessment of greenhouse gas emissions from ecosystems within the Russian Federation, addressing a significant gap in academic research in this area. The study holds considerable practical significance, particularly in the context of global climate goals. By employing a "bottom-up" methodology, the authors have undertaken a thorough estimation of natural emissions of CO2, CH4, N2O, showcasing a thoughtful and systematic approach to research methodology.

The inclusion of updated estimates for forest ecosystems based on State Forest Inventory data and satellite monitoring of forest disturbances, alongside the analysis of grassland ecosystems, enriches the study's content and enhances its credibility.

While the conclusion provides detailed insights into the net absorption of greenhouse gases by Russia's natural ecosystems and offers recommendations concerning anthropogenic emissions, it could benefit from the addition of content highlighting Russia's status as a major nation with abundant timber resources. Specifically, discussing Russia's potential contribution to global carbon neutrality and its proactive role in climate change mitigation efforts would further underscore the country's significance in global environmental conservation efforts and provide valuable insights for future policy formulation and action.

In summary, the manuscript is rich in content, methodologically rigorous, and holds significant importance for assessing greenhouse gas emissions from Russian ecosystems. I suggest that the authors incorporate the aforementioned content into the conclusion to further enrich the significance and depth of the study.

Looking forward to seeing the authors' further refinement of the manuscript and anticipating future research advancements in this field.

Author Response

We would like to sincerely thank to the anonymous reviewers for their time and effort and valuable help in improving the manuscript.

The text describing this issue has been included in the conclusion section:

“Russia's nature ecosystems, especially forest ecosystems, which comprise more than 20% of the global forest area, play a significant role in climate change mitigation. Main efforts should be concentrated on forest fire prevention, improved forest management, reforestation and afforestation, and conservation of intact forest landscapes. Started in 2022, the most important innovative project of national importance, "Russian Climate Monitoring System" aims to intensify research on the fluxes of greenhouse gases in natural ecosystems, which will clarify the country's significance in global environmental conservation efforts and provide valuable insights for future policy formulation and action.”

Reviewer 2 Report

Comments and Suggestions for Authors

The manuscript employs a bottom-up approach to assess carbon sequestration in inland ecosystems, providing clear insights into this critical area of study. However, there are several areas within the manuscript that could benefit from further attention and refinement. The methodology section, while straightforward, could be further enriched by including additional key details that are currently missing. Similarly, the discussion section requires a deeper exploration of certain key points that appear to be underrepresented.

1. Title: It seems that this study includes all inland ecosystems.

2.  Line 11: Revise some in text citations throughout the manuscript. "according to" should be directly followed by the author's name to maintain consistency and clarity in attributing sources. When referencing specific studies, please ensure that the citation is incorporated into a complete sentence with the author's name. Additionally, it is customary in scholarly writing to avoid direct citations in the abstract. Instead, the abstract should summarize the study's aims, methods, results, and conclusions without referencing external sources.

3. The current introduction does not provide sufficient background. A revision and reorganization are required to enhance your research. 1) Explore the existence of similar studies within your study area. Highlighting whether there have been any regional studies related to your topic will offer valuable context and demonstrate the novelty and relevance of your work. This addition will also allow readers to understand how your study fits into the existing body of research. 2) Provide a clear rationale for choosing the bottom-up approach over alternative methods. Discussing the advantages of this approach in comparison to others will help clarify its significance and utility in addressing the research questions.

4. The utilization of multiple models or model estimates in your study enriches your analysis. Incorporating a table that summarizes these models and their respective estimates is required. This table could include key details such as the models' names, major assumptions, and any relevant outcomes or predictions they offer.

4. Incorporating a table to systematically list and describe your data is required. This table will address the current vagueness in data description, providing readers with a clearer, at-a-glance understanding of the foundational elements of your research. Moreover, add a workflow figure to illustrate the accounting process.

5. Remove the dashes from Table 1 and increase the text size in Figure 1 for better readability. The maps in Figure 1 do not add value to this manuscript, delete them.

6. Given the frequent occurrence of fires in boreal forest regions and their capacity to generate significant amounts of pyrogenic carbon (The pyrogenic carbon cycle, https://doi.org/10.1146/annurev-earth-060614-105038), which may remain in the soil for extended periods acting as a long-term carbon sink, it's noteworthy that literature specific to your study area on this topic seems to be lacking. Please include a discussion on this aspect in your study.

7. Wood products represent a significant carbon sequestration pathway via forest ecosystem photosynthesis (see The potential for storing carbon by harvested wood products, https://doi.org/10.3389/ffgc.2022.1055410). Discuss this aspect or incorporating wood products carbon accounting into your study.

Comments on the Quality of English Language

Moderate editing of English language required

Author Response

 We would like to sincerely thank to the anonymous reviewers for their time and effort and valuable help in improving the manuscript.

1. Title: It seems that this study includes all inland ecosystems.	Title modified accordingly: “territory” changed to “all inland ecosystems”
2.  Line 11: Revise some in text citations throughout the manuscript. "according to" should be directly followed by the author's name to maintain consistency and clarity in attributing sources. When referencing specific studies, please ensure that the citation is incorporated into a complete sentence with the author's name. Additionally, it is customary in scholarly writing to avoid direct citations in the abstract. Instead, the abstract should summarize the study's aims, methods, results, and conclusions without referencing external sources.	Text revised accordingly. The authors’ names were added before references. Changed are made in the following lines (using numbering of the version 1): 11, 58, 59, 64, 65, 74, 153, 177, 179, 190, 192, 194, 196, 198, 204, 210, Table 1, 214, 229, 243, 255, 263, 273, Table 2, 294, 306, 309, 312, 328, 340, 351, 352, 376, 384, Table 3, 412, 425, 426, 443, 445, 449, 450, 466, 501, 513, 548, 550.
3. The current introduction does not provide sufficient background. A revision and reorganization are required to enhance your research. 1) Explore the existence of similar studies within your study area. Highlighting whether there have been any regional studies related to your topic will offer valuable context and demonstrate the novelty and relevance of your work. This addition will also allow readers to understand how your study fits into the existing body of research. 2) Provide a clear rationale for choosing the bottom-up approach over alternative methods. Discussing the advantages of this approach in comparison to others will help clarify its significance and utility in addressing the research questions.	The introduction section was revised and restructured more logically. 1)         Similar studies, including regional results (as well as for Russia) are listed in the introduction: “Some data on GHG fluxes from ecosystems of the Russian Federation can be found as part of large regional studies based on bottom-up model calculations [4-7], inverse modeling data [7], and as individual studies for a type of ecosystem [8-12], or for specific types of GHGs [13-15].” “The only attempt to fully assess the role of all ecosystems in Russia (including tundra, forests, steppes, grasslands, marshes, and aquatic ecosystems) in terms of the balance of anthropogenic and natural GHG fluxes on the basis of a bottom-up study was performed by Korotkov et al. [1].”   2) In the introduction the paragraph discussing the advantages and disadvantages of top-down and bottom-up approaches was added: “For estimations of GHG emissions and sinks the “top-down” method based on satellite monitoring and inverse modeling are currently widely applied [6,7,58-60,67]. Top-down approach can ensure continuity of observations over the territory. However, it is uncertain how to determine single sources or sinks from the global spatiotemporal distribution of the GHG concentrations in the atmosphere. To verify results obtained from top-down estimates, data from ground-based, calculated inventory of large anthropogenic sources of emissions as well as data using models of interaction of the atmosphere with the biosphere and the ocean (“bottom-up” approach) are used. The errors in emission top-down estimates increase when moving from global to regional scales and require verification with bottom-up data. Bottom-up estimates are highly accurate at local scale, provide continuous series of measurements or modelling over time but requires more detailed activity data and usually more expensive and therefore are often lacking. At both global and national levels, there is a gap in number of research on integrated assessment of anthropogenic and natural fluxes of all types of major GHGs (carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O)) from ecosystems using the "bottom-up" method. In order to obtain robust GHG data for the stocktake under the Paris Agreement both top-down and bottom-up approaches are to be further developed”.
4. The utilization of multiple models or model estimates in your study enriches your analysis. Incorporating a table that summarizes these models and their respective estimates is required. This table could include key details such as the models' names, major assumptions, and any relevant outcomes or predictions they offer.	A table (new Table 1) incorporating short descriptions of activity data and methods used with appropriate references was added.
4. Incorporating a table to systematically list and describe your data is required. This table will address the current vagueness in data description, providing readers with a clearer, at-a-glance understanding of the foundational elements of your research. Moreover, add a workflow figure to illustrate the accounting process.	We believe that the new Table 1 (see previous comment) incorporate most of the concerns on the current vagueness in data description and methods. In order to clarify accounting procedure and the difference in approaches to separation of natural and anthropogenic fluxes a new Figure 1 was added.
5. Remove the dashes from Table 1 and increase the text size in Figure 1 for better readability. The maps in Figure 1 do not add value to this manuscript, delete them.	All the dashes from Tables 1 and 2 are removed.   The maps from Figure 1 moved to the Supplementary Material. The text size in maps are increased as well as the size of maps itself.
6. Given the frequent occurrence of fires in boreal forest regions and their capacity to generate significant amounts of pyrogenic carbon (The pyrogenic carbon cycle, https://doi.org/10.1146/annurev-earth-060614-105038), which may remain in the soil for extended periods acting as a long-term carbon sink, it's noteworthy that literature specific to your study area on this topic seems to be lacking. Please include a discussion on this aspect in your study.	The reference and discussion on this aspect is included on the page 11 (lines 344-351). There is great uncertainty in the estimates of the reserves of pyrogenic carbon fractions which have varying stability. It remains unclear what proportion of carbon can be buried in the form of stable forms. Inclusion of pyrogenic carbon in the inventory requires additional research and development of special models
7. Wood products represent a significant carbon sequestration pathway via forest ecosystem photosynthesis (see The potential for storing carbon by harvested wood products, https://doi.org/10.3389/ffgc.2022.1055410). Discuss this aspect or incorporating wood products carbon accounting into your study.	The reference and discussion on this aspect has been included on the page 11 (lines 352-360). The present estimations of the contribution of HWP pool is provided in national GHG inventory and is insignificant in Russia.
Moderate editing of English language required	Proofreading of English was done.

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

My comments have been well answered.

Comments on the Quality of English Language

Moderate editing of English language required

Author Response

Dear Reviewer,

 

Thank you very much for your comments and time.

 

We performed English proofreading with native speakers. All changes are made in  track-change mode.

Additionally, we have made corrections based on comments from the Academic Editor's comments:
There some comments for Manuscript (ID: forests-2909769): Figure 2 does not
have a vertical axis and the subscript 2 in CO2. The legend color in Figure 3
is incorrect, and we don’t know the meaning of 1, 2, 3, 4 in horizontal
axis. Missing title on the horizontal axis in Figure 4.

Changes in the title of Figures 2 and 3 are highlighted in yellow. Changes within Figures 2, 3 and 4 are not highlighted, but all comments are accepted.

Best regards, 

Anna Romanovskaya