Spatio-Temporal Differentiation and Driving Factors of Carbon Storage in Cultivated Land-Use Transition

Round 1

Reviewer 1 Report

Spatio-temporal differentiation and formation mechanism of carbon storage in cultivated land-use transition fall in the scope of the journal.  I can only recommend publishing it if the following issues can be addressed properly. 

 I highly recommend modifying and update the first sentence of the introduction with the given studies [1-4] as “Global warming and extreme weather events are caused by the massive emission of greenhouse gases (CO2 and 29 CH4), which hinders sustainable development in human society and production systems [1-4]”

[1] Extreme weather events risk to crop-production and the adaptation of innovative management strategies to mitigate the risk: A retrospective survey of rural Punjab, Pakistan.

[2] Understanding farmers’ intention and willingness to install renewable energy technology: A solution to reduce the environmental emissions of agriculture

[3] Sensitivity analysis of greenhouse gas emissions at farm level: case study of grain and cash crops

[4] Analysis of Energy Input–Output of Farms and Assessment of Greenhouse Gas Emissions: A Case Study of Cotton Growers

** Authors must have to update the above sentence with provided studies [1-4]. 

The main contributions should have been clearly written in the introduction with bullet points. 

I recommend writing figure 1 and table 1 in the section of appendix. 

Please add the numerical values to the bars of figures 2, 3, and 8. 

Do not use any abbreviation in the headings and sub-headings. You must have to take care of it throughout the paper. 

You must have the expansions forms of all abbreviations that have been written in the section of the conclusion. 

Please start the conclusion section with the main objectives and research methods that are used to approach the study main. 

Write the suggestions at the end of the conclusion.

Author Response

We greatly appreciate your valuable suggestions on our manuscript. We have made a deep revision of our manuscript; these changes have been marked in red in the revised manuscript and our point-by-point responses to specific comments are provided below:

1. I highly recommend modifying and update the first sentence of the introduction with the given studies [1-4] as “Global warming and extreme weather events are caused by the massive emission of greenhouse gases (CO2 and 29 CH4), which hinders sustainable development in human society and production systems [1-4]”

[1] Extreme weather events risk to crop-production and the adaptation of innovative management strategies to mitigate the risk: A retrospective survey of rural Punjab, Pakistan.

[2] Understanding farmers’ intention and willingness to install renewable energy technology: A solution to reduce the environmental emissions of agriculture

[3] Sensitivity analysis of greenhouse gas emissions at farm level: case study of grain and cash crops

[4] Analysis of Energy Input–Output of Farms and Assessment of Greenhouse Gas Emissions: A Case Study of Cotton Growers

** Authors must have to update the above sentence with provided studies [1-4]. 

      Thanks very much for your constructive suggestion.

      As suggested, the first sentence of the introduction and references were revised and marked in red in the revised manuscript with track changes.

2. The main contributions should have been clearly written in the introduction with bullet points. 

      Thanks a lot for your valuable suggestion.

      As suggested, the main contributions in the introduction (L101-110) with bullet points were revised and marked in red in the revised manuscript with track changes.

3. I recommend writing figure 1 and table 1 in the section of appendix. 

     Thanks for your valuable suggestion. As suggested, table 1and figure1 were written in the section of appendix.

4. Please add the numerical values to the bars of figures 2, 3, and 8. 

     As suggested, figure 2, 3, and 8 were revised.

5. Do not use any abbreviation in the headings and sub-headings. You must have to take care of it throughout the paper. 

      As suggested, abbreviations in the headings and sub-headings throughout the paper were revised and marked in red in the revised manuscript with track changes.

6. You must have the expansions forms of all abbreviations that have been written in the section of the conclusion. 

      As suggested, the abbreviations in conclusion were written in the expansions forms and marked in red in the revised manuscript with track changes.

7.Please start the conclusion section with the main objectives and research methods that are used to approach the study main. 

      As suggested, the conclusion section was started with the main objectives and research methods in L491-L496 and marked in red in the revised manuscript with track changes.

8. Write the suggestions at the end of the conclusion.

      Thank you for carefully reading our manuscript and your valuable suggestion. As suggested, we added suggestions in the end of the conclusion in L518-L534 and marked in red in the revised manuscript with track changes.

Author Response File: Author Response.pdf

Reviewer 2 Report

I would first thank you for the sound and high-quality (scientifically sound) manuscript you presented for publication. It is of great significance to achieve the target of carbon peaking and carbon neutrality within a predetermined time. However, it needs some few changes before I can accept it for publication.

1. I recommend writing figure 1 in the section of appendix.

2. Try to make this figure or leg-ends more visible and readable.

3. The author should put forward some countermeasures and suggestions based on the analysis results and the carbon neutralization goal.

Author Response

We greatly appreciate your valuable suggestions. We have made a deep revision of our manuscript; these changes have been marked in red in the revised manuscript and our point-by-point responses to specific comments are provided below:

1. I recommend writing figure 1 in the section of appendix.

     Thanks for your valuable suggestion. As suggested, figure1 was written in the section of appendix.

2. Try to make this figure or leg-ends more visible and readable.

     As suggested, the figure was revised.

3. The author should put forward some countermeasures and suggestions based on the analysis results and the carbon neutralization goal.

      Thank you for carefully reading our manuscript and your valuable suggestion. We added suggestions in the end of the conclusion in L518-L534 and marked in red in the revised manuscript with track changes.

Author Response File: Author Response.pdf

Reviewer 3 Report

This is a very interesting article. I think it should be revised before publication.

1. The contribution of the article to the academic community is not well performed. I suggest that the innovation of this paper be explained in the last paragraph of the introduction. In addition, many problems are listed in the penultimate paragraph of the introduction, but this article does not solve them. I suggest that the authors revise this paragraph to match the conclusion.

2. The approach used in this article is the InVEST model. This method is imprecise, and I suggest that authors compare it with other methods and point out the reasons for choosing it.

3. I noticed the word "mechanism" in the title. But the article only reports correlations between factors. There is some speculation in the discussion section, but it is not enough to say "mechanism".

4. I suggest adding some policy recommendations.

Author Response

Reviewer #3：

We greatly appreciate your valuable suggestions. We have made a deep revision of our manuscript; these changes have been marked in red in the revised manuscript and our point-by-point responses to specific comments are provided below:

1. The contribution of the article to the academic community is not well performed. I suggest that the innovation of this paper be explained in the last paragraph of the introduction. In addition, many problems are listed in the penultimate paragraph of the introduction, but this article does not solve them. I suggest that the authors revise this paragraph to match the conclusion.

       We greatly appreciate your suggestion. As suggested, the innovation of this paper was explained in L101-L110 of the introduction. In addition, the penultimate paragraph of the introduction was revised to match the conclusion and marked in red in the revised manuscript.

2. The approach used in this article is the InVEST model. This method is imprecise, and I suggest that authors compare it with other methods and point out the reasons for choosing it.

       Thank you for carefully reading our manuscript and your valuable suggestion. As suggested, the reasons for choosing the InVEST model were pointed out in L158-L161 and marked in red in the revised manuscript with track changes.

3. I noticed the word "mechanism" in the title. But the article only reports correlations between factors. There is some speculation in the discussion section, but it is not enough to say "mechanism".

       Thank you very much for your constructive suggestion. As suggested, the mechanism is replaced by the driving factors in the revised manuscript with track changes.

4. I suggest adding some policy recommendations.

    Thank you for carefully reading our manuscript and your valuable suggestion. We added some policy recommendations and marked in red in the revised manuscript with track changes(L518-L534).

 

 

Author Response File: Author Response.pdf

Reviewer 4 Report

I am pleased to read this paper. It will be a very good addition to the existing literature on the assessment of carbon stocks in China. However, I have the following comments/suggestions:

1.      The paper seems to be focusing more on land use change rather than carbon storage which shall be given more attention.

2.      Terms such as ‘‘multicore fragmentation to mononuclear agglomeration, with obvious regional accumulation, a weakened degree of fragmentation, and uniform distribution’’ etc. shall be mentioned and described quantitatively in the abstract (may be in units such as tons of carbon-lost or gained as a result of land use transition).

3.      Another impression from the paper is that Carbon loss or gain has not been focused because throughout the paper there is no description of Chinese laws/regulations pertaining to land use change.

4.      Figure 4. Shows land use change of higher magnitude from Forest to Cultivated land rather than unused land or other land uses which seems strange given that there are strict regulation of forest protection/conservation in the country. This paper must discuss the land use changes under the spectrum of Chinese laws. If there are gaps or no regulatory mechanisms regarding forests conversion to croplands, then this must be suggested.

5.      Since carbon storage in soils and biomass requires field knowledge and verification then the authors must comment on how was this performed and how the carbon storage estimated from invest model was verified/calibrated from field observations.

Author Response

Reviewer #4：

We greatly appreciate your valuable suggestions. We have made a deep revision of our manuscript; these changes have been marked in red in the revised manuscript and our point-by-point responses to specific comments are provided below:

1. The paper seems to be focusing more on land use change rather than carbon storage which shall be given more attention.

     Thanks for your valuable suggestion. As suggested, more attention on carbon storage were given and marked in red in the revised manuscript with track changes. Since the changes in carbon storage are caused by the transformation of cultivated land use, carbon storage and land use change are inseparable.

2. Terms such as ‘‘multicore fragmentation to mononuclear agglomeration, with obvious regional accumulation, a weakened degree of fragmentation, and uniform distribution’’ etc. shall be mentioned and described quantitatively in the abstract (may be in units such as tons of carbon-lost or gained as a result of land use transition).

      Thanks for your valuable suggestion. As suggested, the terms in the abstract were described quantitatively and marked in red in the revised manuscript with track changes.

3. Another impression from the paper is that Carbon loss or gain has not been focused because throughout the paper there is no description of Chinese laws/regulations pertaining to land use change.

     We greatly appreciate your suggestion. As suggested, we supplemented the laws related to land use change in China in introduction and marked in red in the revised manuscript with track changes. China has promulgated the Regulations for the Implementation of the Land Administration Law of the People's Republic of China. However, with the development of the economy and society, China's land use changes significantly, so the carbon reserves will also change.

     L43-L50 were revised and marked in red in the revised manuscript with track changes.

4. Figure 4. Shows land use change of higher magnitude from Forest to Cultivated land rather than unused land or other land uses which seems strange given that there are strict regulation of forest protection/conservation in the country. This paper must discuss the land use changes under the spectrum of Chinese laws. If there are gaps or no regulatory mechanisms regarding forests conversion to croplands, then this must be suggested.

     We greatly appreciate your suggestion. Figure 4 shows the change of carbon storage in the conversion of farmland use, not just the conversion of forest land to farmland. The increase of carbon storage was mainly due to the transition between unused land and cultivated land. The second is forest, although China has introduced forest land protection policies and laws, there is still a certain transformation between cultivated land and forest land from 1990 to 2020. Due to the large carbon density coefficient between cultivated land and forest land, the carbon storage value of the transformation between them is large, and especially the strong implementation of the policy of re-turning farmland to forest and the protection of the red line of 1.8 billion mu of culti-vated land, the carbon storage change between cultivated land and forest land is large.

     L416-L423 were revised and marked in red in the revised manuscript with track changes.

 

5. Since carbon storage in soils and biomass requires field knowledge and verification then the authors must comment on how was this performed and how the carbon storage estimated from invest model was verified/calibrated from field observations.

     Thanks for your valuable suggestion. L188-L194 and L196-L198 were revised and marked in red in the revised manuscript with track changes.

Carbon density data were collected from a dataset of carbon density in Chinese ter-restrial ecosystems (2010s) of the NESDC (National Ecosystem Science Data Center, https://www.cern.ac.cn). The dataset was established by combining carbon density in Chinese terrestrial eco-systems with relevant experimental data between 2004 and 2014. The dataset included grassland, shrub,forest, cropland and wetland ecosystems in China, and encompassed carbon density data of main components such as above-ground biomass, underground biomass, and soil organic carbon density for different soil depths (0–100 cm). These were used in combination with vegetation[44], soil type[45], climate, physical conditions[46], etc., to calculate the carbon density in the study area

InVEST model was applied to the land use/land cover (LULC) maps to calculate the net change in carbon storage over time for each map cell. The basic assumption of the carbon storage module of InVEST model is that the carbon density of a certain land type is regarded as a constant, and the carbon density of different vegetation types is multiplied by the corresponding area to calculate the regional vegetation carbon storage. Which is widely recognized by scholars at home and abroad.

 

 

 

Author Response File: Author Response.pdf

Reviewer 5 Report

I have had a great pleasure reading and evaluating this interesting article.

The topic and presented reasearch are very current and important in the aspect of athropogenic climate change being a result of environmental global crisis. The paper concerns, in general, the possibility of carbon storage by cultivated lands - to reveal machanisms of carbon storage and trends in effectiveness of C sequestration - in correlation of transfer of land-use types in 1990-2020 period; study area: black soil region of the Songhua River basin area in China.

The rich research results as well as the methodical approach are very interesting and useful to widen the knowledge and practice, how to understand such processes and how to use the land in more sustainable way having environmental benefits in the long term. Also, the methodical approach is very interesting (partly new) - basing on the grid method and recognition of carbon storage density (using InVest model and ArcGis software - including good selection of many indicators (indicating / measuring well researched items).

However, I suggest some modifications / corrections in the paper:

In the ABSTRACT: better description of research results should be included (description - more on point). I mean, better correlation between ABSTRACT  and subsection 3. RESULTS is needed.

In the subsection 1. INTRODUCTION the aim of research should be directly formulated (clearly and directly, not blurred).

In general, the paper is very important, as regards cognitive significance in the  methodical approach and rich results helping to solve problems with correlation of land-use structure / quality and carbon storage possibilities to mitigate anthropogenic climate change consequences. The paper is worth of publishing after minor corrections

 

Author Response

Reviewer #5：

We greatly appreciate your valuable suggestions. We have made a deep revision of our manuscript; these changes have been marked in red in the revised manuscript and our point-by-point responses to specific comments are provided below:

1. In the ABSTRACT: better description of research results should be included (description - more on point). I mean, better correlation between ABSTRACT and subsection 3. RESULTS is needed.

      Thanks very much for your constructive suggestions. As suggested, abstract was revised and marked in red in the revised manuscript with track changes.

2. In the subsection 1. INTRODUCTION the aim of research should be directly formulated (clearly and directly, not blurred).

     Thanks a lot for your constructive comments and suggestions. As suggested, the aims of research were clearly and directly formulated in L107-L110 and marked in red in the revised manuscript with track changes.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Appreciate efforts, the manuscript has been significantly improved, I am satisfied with the revisions, however, I have concern about references , the reference style is not consist, please use the "Chicago Style" and revise all the references accordingly. The details about reference styles can also be found here.

https://www.mdpi.com/journal/sustainability/instructions#references