Temporal and Spatial Variation of Vegetation in Net Primary Productivity of the Shendong Coal Mining Area, Inner Mongolia Autonomous Region

Round 1

Reviewer 1 Report

I have read your study. The paper focuses on the spatial-temporal evolution and influencing factors of vegetation NPP in Shendong mining area. In general, the paper has a certain reference value. However, there are still many problems in the paper. It is suggested to Accept after modification. The specific comments are listed below.

（1）The Foundation Item should indicate the specific source of the foundation, such as the National Nature Science Foundation of China.

（2）Mengdong and Mengxi mining areas，Is this statement appropriate?

（3）The references in the last line of the first page are not standardized.

（4）The evaluation of various NPP estimation models did not cite any references.

（5）The paper does not cite relevant references in many places.

（6）There are many grammatical problems in the paper,.

（7）The study also analyzed climate factors to determine both qualitative and quantitative aspects of environmental health in Shendong. What are the quantitative aspects in the paper?

（8）Because the paper discusses the impact of meteorological factors on NPP in the follow-up, precipitation and temperature should be emphasized in the introduction of the study area.

（9）Figure 1 can be merged into one figure, and the title of Figure 1 also has problems.

（11）How to obtain monthly NPP data based on MOD13Q1?

（12）The introduction of ground sample data collection process is not comprehensive, and the relationship between 25*25 and 1*1 cannot be understood through the paper.

（13）The introduction of meteorological data does not introduce which meteorological data are obtained, what is its time scale, monthly or yearly?

（14）What is the meaning of variable projection importance discrimination index (VIP)? What is the purpose of introducing this parameter?

（15）Why are 55 sample points selected for verification with MOD17A3?

（16）How to obtain the data used in Figure 4? It should be detailed in the paper.

（17）How to determine the extremely significant and weakly significant in Figure 6?

（18）Why is the legend in Figure 9 inconsistent with the value range described in the paper?

（19）All the result figures in the paper do not explain how to obtain the results. Although many methods are introduced in the research methods, in order to better let readers understand, it is best to explain how to obtain the results in the text, and then express them with figures.

（20）It is suggested to add the range of directly affected area and natural growth area to the result figures.

Author Response

To Reviewer #1:

Thanks for your valuable comments on our paper. Your comments are of great assistance to us for improving and revising our manuscript so as to be acceptable for publication. We had tried to revise and improve the manuscript in line with the suggestions made by you and other reviewers. The changes to each point were listed below.

Reviewers' comments:

Reviewer #1: Dear Authors,

I have read your study. The paper focuses on the spatial-temporal evolution and influencing factors of vegetation NPP in Shendong mining area. In general, the paper has a certain reference value. However, there are still many problems in the paper. It is suggested to Accept after modification. The specific comments are listed below. 

1.The Foundation Item should indicate the specific source of the foundation, such as the National Nature Science Foundation of China.

Responses: Thanks for your suggestions. According to your modification suggestion, we have added the source of foundation in the foundation item.The foundation is Inner Mongolia Autonomous Region key research and development project.

2. Mengdong and Mengxi mining areas，Is this statement appropriate?

Responses: This is very nice and constructive comments.  We searched relevant literature and found that Inner Mongolia was divided into eastern Mongolia, Central Mongolia and western Mongolia according to its economic development. We found relevant literature and introduced it into the article. The study area is located in central Mongolia, and we have also made modifications.

Please check file titled 'Revision, changes marked' on page 2, lines 3–5: ' Its coal resources are widely but densely distributed in the Mengdong and Mengxi Mengzhong mining areas(Wang et al. , 2012). Together these represent a hundred mil-lion tons of the national large coal base. The Mengzhongxi mining area is located in Ordos City, Inner Mongolia and includes the Shendong coal fields.' 

3. The references in the last line of the first page are not standardized..

Responses: Thank you for your comments. We found the problem with your index and changed the format of the reference.

In the paper, this portion had been added to the page 2, lines 2–3: ' The Inner Mongolia Autonomous Region is a key area of China's westward migrating coal mining strategy (Xiao et al., 2019).'

4. The evaluation of various NPP estimation models did not cite any references.

Responses: This is very advisable comments. We reintroduced references to the NPP evaluation model.For details of the revisions please check this in the file titled 'Revision, changes marked' on page 2, lines 24-27. 'Climate models produce results with relatively high uncertainty terms because they do not consider vegetation related information (Zhou et al., 1995). Light energy utilization models include light energy transfer and conversion processes but these remain somewhat uncertain (Field et al., 1995). Process models require many parameters that are either uncertain or difficult to obtain (Wang et al., 2002). '

Zhou, G.S., Zhang, X.S., 1995. Model of net primary productivity of natural vegetation. Chinese Journal of Plant Ecology. 1995(03):193-200. https://CNKI:SUN:ZWSB.0.1995-03-000.

Field C.B., Randerson J.T., Malmströ m CM. 1995. Global net primary production: Combining ecology and remote sensing. Remote Sensing of Environment, 51(1). https://doi.org/10.1016/0034-4257(94)00066-V.

Wang Z.M., Liang Y.L., 2002. Progress in Vegetation Net Primary Productivity Model Research. Journal of Northwest Forestry University. (02):22-25. https://doi.org/10.3969/j.issn.1005-3409.2005.03.041

5. The paper does not cite relevant references in many places.

Responses: Your suggestion is very necessary, and we have added several references in the paper. For example, references (Zhou et al., 1995), (Field et al., 1995) and (Wang et al., 2002) were introduced in the research background. References (Shao et al., 2022) are introduced into the survey of the research area. References (Han et al., 2019), (Xiao et al., 2019), (Wang et al., 2012) and so on were introduced into the research methods.For details of the revisions please check the references in the file titled 'Revision, changes marked'.

6. There are many grammatical problems in the paper,.

Responses: Thank you for your advice. we use one of the editing services (https://www.mdpi.com/authors/english) . and a lot of grammatical corrections have been made to the article.For details of the revisions please check this in the file titled 'Revision, changes marked'.

7. The study also analyzed climate factors to determine both qualitative and quantitative aspects of environmental health in Shendong. What are the quantitative aspects in the paper?

Responses: This is very advisable comments. Indeed, we did not express too much quantitative analysis of meteorological factors, because considering that the main research content of this paper is the inversion and influence of NPP, the increase of quantitative research content will make us feel that the paper is not refined enough. We also decided to reduce this part of the content after discussion. The suggestions you give us will be refined and quantified in future research. Thank you for your understanding.'The annual average precipitation in the area is 320~400mm, and the inter-annual var-iation of precipitation is great. The precipitation in wet years is about 3 times that in dry years. The annual distribution is uneven, and the precipitation is small and con-centrated, mainly in June to September, accounting for about 3/4 of the whole year, mostly in the form of heavy rain, with strong bursts. The annual average temperature is 7.3℃, the annual extreme maximum temperature is 38.8℃, and the annual extreme minimum temperature is -28.1℃.'

8. Because the paper discusses the impact of meteorological factors on NPP in the follow-up, precipitation and temperature should be emphasized in the introduction of the study area.

Responses: This is a very important suggestion.Combined with the previous research, we introduced the precipitation and temperature in the study area.For details of the revisions please check this in the file titled 'Revision, changes marked' on page 3, lines 24-30.

9. Figure 1 can be merged into one figure, and the title of Figure 1 also has problems.

Responses: This is a nice and interesting comment. We have made changes based on your comments, merging Figure 1 and changing the content of the title.For details of the revisions please check this in the file titled 'Revision, changes marked' on page 5, lines 1-2.

10. How to obtain monthly NPP data based on MOD13Q1?

Responses: According to the comments, We combed the whole paper and found that the NDVI data required in this paper are MOD13Q1, 250M and 16D. NPP data is MOD17A3, 1Km, 1A. The data came from NASA.(https://ladsweb.modaps.eosdis.nasa.gov/search/order/2). Among them, we did not obtain monthly NPP data. In this paper, MOD17A3 was selected to obtain annual NPP, which was used to verify our simulated annual NPP value.Thank you very much for your proposal. We will conduct model verification from the perspective of monthly in the future research.

11. The introduction of ground sample data collection process is not comprehensive, and the relationship between 25*25 and 1*1 cannot be understood through the paper.

Responses: Your opinion is very reasonable. Indeed, this part of the content is not clearly expressed. We selected 25*25m as a large quadrat, including herbs, trees and other vegetation. Within this range, we selected three 1* 1M quadrats to measure the average NPP of grassland, so as to reduce the error caused by one 1*1m quadrats. At the same time, we estimated the NPP of tree vegetation in the large square. In this way, we can estimate the NPP of the large square by combining the coverage of each vegetation, and finally determine the NPP value per unit area.

For details of the revisions please check this in the file titled 'Revision, changes marked' on page 5-6, The title 2.2.2.'Considering the diversity of vegetation types in the study area, 25 × 25 m was selected as the large plot. In these areas, three 1 x 1 m grassland plots were selected for biomass sampling, and the average value was later taken as grassland biomass. The plots measured 25 × 25 m. Within these, three 1 x 1 m plots of grassland along the greater plot’s diagonal were sampled for biomass. Biomass was collected, weighed immediately, labeled and transported back to the laboratory for analysis. In the lab, samples were dried at 75℃ to obtain biomass dry weight data. NPP was estimated from each sample square as proportions of above-ground biomass relative to be-low-ground biomass assuming a NPP conversion coefficient of 0.475 (Li et al., 2021). Trees found in the study area include sand willow and poplars. Trees within large plots include sand willow and poplar trees.We counted the number of trees in each plot and estimated the size of each individual from its diameter at 1.3 m above the ground. Bi-omass and corresponding NPP of the forested land was estimated according to the al-gorithm proposed by Fan Wenyi and others (Fyllas et al., 2017). This rate combined with forest cover was integrated into areal estimates of total NPP per sample plot.Finally, the coverage of grassland and trees was integrated into the total NPP area of each plot.Finally, NPP per unit area is determined by combining the area of the large square.'

12. The introduction of meteorological data does not introduce which meteorological data are obtained, what is its time scale, monthly or yearly?

Responses: The daily data of precipitation and temperature from 2000 to 2019 were collected from six standard meteorological stations in the study area and its surrounding areas. After calculating monthly precipitation and average temperature data by summing and averaging methods.. Using ANUSPLIN to break it into a grid Data were parsed into a grid to match the projection for the study area and resolution of NPP da-ta.

13. What is the meaning of variable projection importance discrimination index (VIP)? What is the purpose of introducing this parameter?

Responses: Thank you for your question. We use VIP namely Variable Influence on Projection. It is an important index in partial least squares, and has the advantages of principal component analysis and multiple regression. The score of the original variable was evaluated by VIP value, and then the variables with strong correlation with the dependent variable were found. The larger the value, the stronger the explanatory power. This index is used in this paper to judge the influence of temperature, precipitation and human activities on NPP, which can effectively avoid the multivariate collinearity problem caused by strong interaction between precipitation, temperature and human activities.

14. Why are 55 sample points selected for verification with MOD17A3?

Responses: We selected 55 sample points for NPP verification, considering that the accuracy of Modis NPP finished data is 1KM, in order to better apply to model verification and reduce errors. Combined with the scope of the study area, we divided a grid of 7 vertical and 8 horizontal with an interval of 10KM, and selected 55 sample points in the study area.

15. How to obtain the data used in Figure 4? It should be detailed in the paper.

Responses: Your suggestion is very necessary. Figure 4 shows the inter-annual variation of NPP in the study area from 2000 to 2019. In this paper, the CASA model was used to simulate the monthly NPP value. After accumulating the NPP value of 12 months each year, the average value of the whole study area was taken as the annual NPP value of that year.

For details of the revisions please check this in the file titled 'Revision, changes marked' on page 9, The title 3.2.'According to the monthly NPP data simulated by CASA model, the total value of NPP over the past years was obtained, and then the average value of NPP in the study area was taken as the annual value of NPP over the past years. '

16. How to determine the extremely significant and weakly significant in Figure 6?

Responses: On this issue, we do not fully express in the text. We have updated the definition of highly significant and salient in title 2.3.2. For details of the revisions please check this in the file titled 'Revision, changes marked' on page 7.'For a given confidence interval (significance level) α, absolute values of Z equal to or exceeding 1.65, 1.96, and 2.58 give respective significance levels of 90%, 95%, and 99%. If | Z |≥ Z1-α/2, the assumption of an upward or downward trend cannot be re-jected (the null hypothesis does not obtain). Positive values indicate an upward trend, and negative values indicate a downward trend. According to the t-test cutoff value, When | Z |> 1.65, the increasing or decreasing trend is weak significant at the 0.1 level. when | Z |> 1.96, the increasing or decreasing trend is significant at the 0.05 level. When | Z |> 2.58, the increasing or decreasing trend is extremely significant at the 0.01 level.'

At the same time, we improved the quality of Figure 7.

17. Why is the legend in Figure 9 inconsistent with the value range described in the paper?

Responses: This problem does exist in the paper. Due to our negligence, the content of the paper was not filled in according to the figure, so we revised the content of the text in time. Change '-0.6 to -0.92' and '-0.72 to -0.77' to '-0.60 to 0.92' and '-0.72 to 0.77'.Thank you for your modification suggestions, so that we can timely modify.

18. All the result figures in the paper do not explain how to obtain the results. Although many methods are introduced in the research methods, in order to better let readers understand, it is best to explain how to obtain the results in the text, and then express them with figures.

Responses: Thank you for your suggestion. According to your modification suggestion, we have explained the calculation results of trend analysis, human activities and partial correlation analysis in the paper. For details of the revisions please check this in the file titled 'Revision, changes marked'.The amendments include sections 3.2, 3.3 and 3.4.

19. It is suggested to add the range of directly affected area and natural growth area to the result figures.

Responses: Your suggestion is very necessary. We have revised all the drawings in the article to increase the scope of natural recovery area and direct impact area.And improve the quality of all the figure.

I am very appreciating all your suggestions, comments and favorable consideration again. We have answered the above questions carefully and also reflected in the article. Please check the answers above.

I hope that these revisions and the improved text will be satisfactory and make the paper be acceptable for publication.

Reviewer 2 Report

Paper entitled “Temporal and spatial variation in net primary productivity of the Shendong coal mining area, Inner Mongolia Autonomous Region” meets the necessary standards for publication in this journal.

Please check the entire manuscript carefully for eventual typographical errors.

Attention when writing references. They are not unitary.

Final Conclusion: The paper meets the necessary standards for publication.

Author Response

To Reviewer #2:

Thanks for your valuable comments on our paper. Your comments are of great assistance to us for improving and revising our manuscript so as to be acceptable for publication. We had tried to revise and improve the manuscript in line with your suggestions.

Reviewers' comments:

Reviewer #2: Dear Authors,

Paper entitled 'Temporal and spatial variation in net primary productivity of the Shendong coal mining area, Inner Mongolia Autonomous Region' meets the necessary standards for publication in this journal.

Please check the entire manuscript carefully for eventual typographical errors.

Attention when writing references. They are not unitary.

Final Conclusion: The paper meets the necessary standards for publication..

Responses: Thanks for your very positive and advisable suggestions. we use one of the editing services (https://www.mdpi.com/authors/english) . and a lot of grammatical corrections have been made to the article.For details of the revisions please check this in the file titled 'Revision, changes marked'.

I am very appreciating all your suggestions, comments and favorable consideration again. We have answered the above questions carefully and also reflected in the article. Please check the answers above.

I hope that these revisions and the improved text will be satisfactory and make the paper be acceptable for publication.

Reviewer 3 Report

Good research work.

There are improvement could be done.

1. Suggest 'vegetaion' in the title, Temporal and spatial variation of vegetation in net primary productivity of the Shendong coal mining area, ...

2. page 1, line 34, 'Yao et al., 2012' --> missing reference.

3. page 2, line 32, 'areas.By' --> missing space after dot.

4. page 3, line 27, 'mining, In' --> 'mining, in'

5. page 3, line 34, 'so on.Combined' --> missing space after dot.

6. page 5, line 7, 'Fan Wenyi' --> reference?

7. page 5, line 19, '2019).Distri-' --> missing space after dot.

8. page 5, line 34, 'where' --> no indentation.

9. page 5, line 39, 'where' --> no indentation.

10. page 6, line 9, 'where' --> no indentation.

11. page 6, line 9, 18, 24, 36, 'where' --> no indentation.

12. page 7, line 1, 12, 22, 'where' --> no indentation.

13. page 7, line 17, '(Wang et al., 1999)' --> missing reference.

14. page 10, line 26, 'Figure 8a' --> 'Figure 9a' ?

15. page 10, line 29, 'Figure 8b' --> 'Figure 9b' ?

16. page 15, reference 3. Hu et al., 2018 --> no citation in paper.

17. page 15, reference 4. Yang et al., 2019 --> no citation in paper.

18. page 17, reference 25. Luo et al., 2002 --> no citation in paper.

19, page 17, reference 31. --> missing 2015 between 'J. G.' and 'NPP'.

20. page 17, reference 31. --> missing space between '2010.' and 'Journal'.

 

Author Response

To Reviewer #3:

Thanks for your valuable comments on our paper. Your comments are of great assistance to us for improving and revising our manuscript so as to be acceptable for publication. We had tried to revise and improve the manuscript in line with your suggestions.

Reviewers' comments:

Reviewer #3: Dear Authors,

Good research work.There are improvement could be done.

1. Suggest 'vegetaion' in the title, Temporal and spatial variation of vegetation in net primary productivity of the Shendong coal mining area, ...

Responses: Thanks for your very positive and advisable suggestions.We think your suggestion is very necessary.We changed the title of 'Temporal and spatial variation of vegetation in net primary productivity of the Shendong coal mining area, Inner Mongolia Autonomous Region'.For details of the revisions please check this in the file titled 'Revision, changes marked'.

2. page 1, line 34, 'Yao et al., 2012' --> missing reference.

Responses: Thank you for reminding us that we have added this article to the reference.

(Yao, G.Z. Effect of coal mining subsidence on ecological environment and recovery technique. doctoral thesis. Beijing forestry university. Beijing. 2012.)For details of the revisions please check this in the file titled 'Revision, changes marked'.

3. page 2, line 32, 'areas.By' --> missing space after dot.

Responses: Thank you for your comments. We have added a space here in the text.For details of the revisions please check this in the file titled 'Revision, changes marked'.

4. page 3, line 27, 'mining, In' --> 'mining, in'

Responses: Thank you for your comments. We have changed 'mining, In 'to 'mining, in'.For details of the revisions please check this in the file titled 'Revision, changes marked'.

5. page 3, line 34, 'so on.Combined' --> missing space after dot.

Responses: Thank you for your comments. We have added a space here in the text.For details of the revisions please check this in the file titled 'Revision, changes marked'.

6. page 5, line 7, 'Fan Wenyi' --> reference?

Responses: Thank you for reminding us that we have added this article to the reference.For details of the revisions please check this in the file titled 'Revision, changes marked'.

(Fan, W.Y.; Zhang, H.Y. Comparison of three models of forest biomass estimation. Chinese Journal of Plant Ecology, 2011, 35(04):402-410, https://doi.org/10.3724/SP.J.1258.2011.00402).

7. page 5, line 19, '2019).Distri-' --> missing space after dot.

Responses: Thank you for your comments. We have added a space here in the text.For details of the revisions please check this in the file titled 'Revision, changes marked'.

8. page 5, line 34, 'where' --> no indentation.
9. page 5, line 39, 'where' --> no indentation.
10. page 6, line 9, 'where' --> no indentation.
11. page 6, line 9, 18, 24, 36, 'where' --> no indentation.
12. page 7, line 1, 12, 22, 'where' --> no indentation.

Responses: Thanks for your very positive and advisable suggestions.About 8-12 tips. We changed it to not indent.For details of the revisions please check this in the file titled 'Revision, changes marked'.

13. page 7, line 17, '(Wang et al., 1999)' --> missing reference.

Responses: Thanks for your very positive and advisable suggestions.

We have updated the reference here to (Wang et al., 2000) and we have added this article to the reference.For details of the revisions please check this in the file titled 'Revision, changes marked'.

(Wang, H.W.; Zhang, Q. Identification of optimal subspace from PLS regression. Journal of Beijing University of Aeronautics and Astronautics 2000, (04), 473-476. DOI:10.13700/j.bh.1001-5965.2000.04.027.)

14. page 10, line 26, 'Figure 8a' --> 'Figure 9a' ?
15. page 10, line 29, 'Figure 8b' --> 'Figure 9b' ?

Responses: You are absolutely right. We did write the names of the two pictures wrong. We have changed the names of the two pictures to 'Figure 9a' and 'Figure 9b' respectively. For details of the revisions please check this in the file titled 'Revision, changes marked'.

16. page 15, reference 3. Hu et al., 2018 --> no citation in paper.
17. page 15, reference 4. Yang et al., 2019 --> no citation in paper.
18. page 17, reference 25. Luo et al., 2002 --> no citation in paper.

Responses: Thanks for your very positive and advisable suggestions.We have deleted the three references you mentioned, and the paper does not involve these references. For details of the revisions please check this in the file titled 'Revision, changes marked'.

19.page 17, reference 31. --> missing 2015 between 'J. G.' and 'NPP'.

Responses: Thanks for your very advisable suggestions. We have added 2015 to reference 31. For details of the revisions please check this in the file titled 'Revision, changes marked'.

20. page 17, reference 31. --> missing space between '2010.' and 'Journal'.

Responses: Thanks for your very positive suggestions. We have added a space here in the text. For details of the revisions please check this in the file titled 'Revision, changes marked'.

I am very appreciating for your careful review and constructive suggestions again. We have carefully tried our best to revise and improve the discussion, and also reflected in the discussion sections of the article.

 I hope that these revisions and the improved text will be satisfactory and make the paper be acceptable for publication.

Reviewer 4 Report

Comments for author File: Comments.pdf

Author Response

To Reviewer #4:

Thanks for your valuable comments on our paper. Your comments are of great assistance to us for improving and revising our manuscript so as to be acceptable for publication. We had tried to revise and improve the manuscript in line with your suggestions.

Reviewers' comments:

Reviewer #4: Dear Authors,

The author analyzes Temporal and spatial variation in net primary productivity of the Shendong coal mining area, Inner Mongolia Autonomous. The data is helpful for future ecological restoration of vegetation. here are some specific comments:

1. The authors need to find native English speakers to reorganize the sentence structure and grammar. it is hard to read and understand for the reader.

Responses: Thanks for your very positive and advisable suggestions. we use one of the editing services (https://www.mdpi.com/authors/english) . and a lot of grammatical corrections have been made to the article.For details of the revisions please check this in the file titled 'Revision, changes marked'.

2. The paper can be more complete if the author could give some suggestions on how to restore or protect the vegetation in the discussion section.

Responses: Thanks for your very advisable suggestions.At the end of the paper, we add this part as follows: In general, although the vegetation in the study area has been improved in the past 20 years, considering that the influence of regional climate conditions on vegetation growth is weak, it is necessary to strengthen the protection and restoration of the vegetation in the study area in order to ensure the stability of the ecological environment in the area in the future. It is suggested that the study area should improve its ecological construction in the future. Select plants that can simultaneously tolerate stress from specific metals, drought, and low nutrient levels. At the same time, the mining environment management and supervision should be strengthened to ensure the stable improvement of vegetation ecological management in Shendong mining area.

3. Part of the information should be move to 'introduction'.

Responses: Thanks for your very positive and advisable suggestions.We have moved part of subsection 2.1 into subsection 1. For details of the revisions please check this in the file titled 'Revision, changes marked'. Section 1 Introduction. 'In the case of subsidence and collapse, mining of subsurface coal seams removes support and thereby disrupts the overlying surface. Mine subsidence has harmed  vegetation, soil, and other aspects of the local ecosystem. With the accumulation of time, the original ecological vegetation is gradually degraded and only distributed in sporadic are-as. Relatively speaking,  The proportion of artificial vegetation is 60 per cent year by year (Li et al., 2011).

4. I didn't see Fig 1 in your main text.

Responses: Thanks for your very positive suggestions. We added the expression of Figure 1 in the introduction of the research area.For details of the revisions please check this in the file titled 'Revision, changes marked'. Section 1 Introduction.

5. Please re write it.'Field data howevercan effectively validate models.'

Responses: Thanks for your very positive suggestions. We changed the original 'biomass conversion NPP data are often used instead of field NPP data. Field data however can effectively validate models.' to 'biomass conversion NPP data is usually used instead of field NPP data for data model validation NPP data are often used instead of field NPP data. Field data however can effectively validate models.'

6. Did you collected all kinds of plants or some of them? More detail needs to add it.'Biomass was collected.'

Responses: Thanks for your valuable comments on our paper. We collected all parts of herbaceous vegetation in the plots. So we changed the original 'Biomass was collected.' to 'The biomass of herbaceous vegetation was collected'.

7. How long?'75℃ to obtain'.

Responses: Your suggestion is very necessary.We changed the original ' samples were dried at 75℃ to obtain biomass dry weight data.'to' Biomass dry weight data were obtained after samples were dried at 75°C for 12 hours.'

8. Should be move to introduction.'Due to its utilization of satellite remote sensing technology, the CASA model has become widely used in estimating NPP in terrestrial ecosystems and in global carbon cycle research.'

Responses: Your suggestion is very necessary.We have moved this to the third paragraph of the introduction.For details of the revisions please check this in the file titled 'Revision, changes marked'.

I am very appreciating for your careful review and constructive suggestions again. We have carefully tried our best to revise and improve the discussion, and also reflected in the discussion sections of the article.

 I hope that these revisions and the improved text will be satisfactory and make the paper be acceptable for publication.

Round 2

Reviewer 1 Report

After careful revision by the author, it is recommended to accept in present form.

Author Response

Dear professor,

Thank you for your comments. This manuscript has been edited by a professional English editor.

Best regards,

Jia ke

Reviewer 4 Report

I am impressed with the revisions made to the manuscript by the authors. But there are still some language issues in the manuscript, please double-check the language and grammar.

Author Response

Dear professor,

Thank you for your comments, this manuscript has been edited by a professional

English editor.

Best regards,

Jia Ke