Effects of Water-Level Fluctuation on Soil Aggregates and Aggregate-Associated Organic Carbon in the Water-Level Fluctuation Zone of the Three Gorges Reservoir, China

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The overall comments are as follows:

·         The title of the manuscript is well and readable.

·         The abstract of the manuscript is written well.

·         The keywords are written well.

·         Please add some lines in the first paragraph of the introduction about the study.

·         Please add more recent references in the introduction sections .

·         Please add some about the purple soil.

·         Please elaborate on the methodology of soil sample collection design.

·         Why are the effects of the depth of soil not indicated in the manuscript?

·         Please add the make and name of the company that made the soil corer and sieve used in the study.

·         Please write about the alphabet written in Figures 1, 2, 3, 4 and 5.

·         Please write about the line shown in Figures 1, 2, 3, 4, and 5.

·         Figures 6 and 7 are without statistical analysis, please do the statistical analysis in these two figures.

·         Please discuss the statistical analysis in the results.

 

·         In discussion a few references are mentioned; please add more new references in this section.

Author Response

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Reviewer 2 Report

Comments and Suggestions for Authors

Overall, the paper titled "Effects of Water Level Fluctuation on Soil Aggregates and Aggregate-Associated Organic Carbon in the Water Level Fluctuation Zone of the Three Gorges Reservoir, China" presents an important study on the impact of water level fluctuation (WLF) on soil aggregates and associated organic carbon in the three Gorges Reservoir area. Here are some comments to consider for improving the paper:

1.      Please incorporate one or two additional keywords.

2.      The introduction provides a comprehensive background but lacks focus. It could be streamlined by removing redundant information and emphasizing the gap in knowledge.

3. Line 37: “best recognized” could be changed to “best known” for clarity.
4. Line 41: “biogeochemical processes, and is a research hotspot of global carbon cycle” could be rephrased for better flow. For example: “...biogeochemical processes, making it a focal point in global carbon cycle research.”
5. Lines 42-44: “Within the elevation range of 145~175 m on both sides of the reservoir area, a reservoir fluctuation zone with a fluctuation range of up to 30 m is formed, which is contrary to the fluctuation season of natural rivers” could be clarified for better readability.
6. Line 119: Replace “purple sample plot” with “plot with purple soil”.

7.      Clarify the rationale behind choosing the specific elevations (145 m, 155 m, 165 m) for sampling. Were these elevations chosen based on previous studies or ecological considerations?

8. Line 176: Put space before (Fig. 2).
9. Lines 203-205: “while at 0-10 cm soil depth in the fluctuation zone, the organic carbon content in bulk soil in SI region was obviously lower than that of MI region and LI region" could be rephrased for clarity. For example: "while in the 0-10 cm soil depth of the fluctuation zone, the organic carbon content in bulk soil was significantly lower in the SI region compared to the MI and LI regions."

10.  The heading "3.4." appears twice. Please rectify this repetition.

11.  Suggest potential areas for future research based on the findings of this study.

12.  The research suggests that the increase in labile carbon content in macro-aggregates following water level fluctuations might indicate a decrease in the stability of SOC within these aggregates. Could the authors elaborate on the implications of this finding for long-term soil carbon sequestration dynamics? How might the observed increase in labile carbon content influence overall soil health and resilience to environmental stressors in the WLFZ?

13.  The research emphasizes the importance of considering the temporal scale in studying SOC dynamics in response to water level fluctuations. In light of this, what are the potential implications of short-term versus long-term fluctuations in water levels on soil aggregation, organic carbon storage, and soil health? How might incorporating a longer temporal perspective enhance our understanding of soil-ecosystem interactions in dynamic environments like the Three Gorges Reservoir?

 

Author Response

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Author Response File: Author Response.docx

Reviewer 3 Report

Comments and Suggestions for Authors

Dear Editor and Authors,

I have revised the manuscript entitled: Effects of Water Level Fluctuation on Soil Aggregates and Aggregate Associated Organic Carbon in the Water Level Fluctuation Zone of the Three Gorges Reservoir, China. The aims of the manuscript are to: (1) identify the dynamics of aggregate distribution; (2) measure the dynamics of SOC and labile carbon content in different particle size aggregates; (3) identify the contributions of soil aggregates to SOC sequestration in the water level fluctuation zone of the Three Gorges Reservoir. The topic is in scope of the journal. The methods and techniques are accurate and very common.  While the novelty of the research is not very high, the present one is very well presented and the case study is very good and worthwhile. The experience of the authors is genuine, and in my opinion the manuscript can be considered for publication. The paper has genuine work behind it, and identifies the need for additional research in this important issue. Therefore, my opinion is that the work can be accepted for the publication.

Author Response

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Reviewer 4 Report

Comments and Suggestions for Authors

Changing water levels in rivers can lead to the destruction of soil aggregates and, in turn, to the soil's loss of various forms of carbon. The research concerns vast areas of the basin of one of China's rivers. Abstract concise and readable. Research methods well suited to the subject matter under study. Introduction to the research extensive, introducing us well to the subject matter of the problem under study. The authors of the article present the results of the research in numerous charts.  One of the conclusions convicts, the effect of climate change on soil carbon sequestration and the persistence of aggregates of different diameters and depths (0-10, 10-20cm). 

 Notes to authors:

Why the authors did not analyze the granulometric composition of the sequestered soil aggregates in their study.  Other minor comments mainly concern the References section. Lines for improvement are given in the review: 

line 107: hm2 what is the unit?,

line 366: no break Fig.5

line 429: boil?

line 450: name of WETLANDS magazine in font - italic?

 

 

Author Response

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Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

Dear Authors,

You all have done excellent work in revising the manuscript. All the comments are incorporated into the manuscript. However, it still needs to add some minor corrections to the manuscript.

·       Please add the world classification of the soil in the study area.

·         The abbreviation written in the manuscript for the first time could be used throughout the manuscript without full form.

 

·         The figures show significant differences, but were not written on the results; kindly write them in the results section or remove the non-significant results.

Author Response

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