Simulation of Grassland SOC under Future-Climate Scenarios in Gansu, China
Round 1
Reviewer 1 Report
General Comments
1. In the methods section,
I got no file related to Supplementary document, but just to remind the author to ensure all data use is similar to those mentioned in the methods section. Particularly data for SOM sub-model, if used SOM pool fraction, mentioned methods used for SOM fractionation methods
2. Results section need some additional information and adjustments
- graph in Fig 6 need more clarity. The mini graph in map that represent SOC (gC/m2) should put with y and x axis for unit value references. Moreover, the color confusing reader because use similar with colour of simulation scenario
3. Discussion section
This part needs some adjustment additional discussion
Author needs to explain more what the implication of the prediction related to recent management and utilization of the grassland
4. Conclusion section
I suggest author to add implication of the research in management and utilization grassland area in the future.
Minor comments
Line 13-14: change into “Pearson coefficient diagram was used to analyze …..”
Line 205: please check and re write again the caption in more clarity. In for fig 4. Is the simulation A-F or A-E as explained in table 1?
Line 218-219: please check again, is fig 5d represent CO2 and temperature increase? as table 1, this should represent simulation C
Line 220-221: similar to previous comment, please check again, should this fig 5e represent simulation D?
Line 221: decrease in SOC
Line 240: Check again legend of map in figure 6. duration of simulation 2019-2048 or 2019-2044?
Line 306: similar to previous comment, is this correct 2019-2048?
Author Response
Point 1: In the methods section
I got no file related to Supplementary document, but just to remind the author to ensure all data use is similar to those mentioned in the methods section. Particularly data for SOM sub-model, if used SOM pool fraction, mentioned methods used for SOM fractionation methods
Response 1: Thank you for drawing our attention to that. Sorry for the mistake, we have uploaded the supplementary document now, and we make sure that all data use is similar to those mentioned in the methods section.
Point 2: Results section need some additional information and adjustments
graph in Fig 6 need more clarity. The mini graph in map that represent SOC (gC/m2) should put with y and x axis for unit value references. Moreover, the color confusing reader because use similar with colour of simulation scenario
Response 2: Thank you for your careful review. We have added the y and x axis for unit value references in the Fig 6, and change the color of mini bar, thanks a lot.
Point 3: Discussion section
This part needs some adjustment additional discussion
Author needs to explain more what the implication of the prediction related to recent management and utilization of the grassland
Response 3: Thanks for your advice. We have explained more about it in the discussion from line 296 to line 307, and added two more references.
Pont 4: Conclusion section
I suggest author to add implication of the research in management and utilization grassland area in the future.
Response 4: Thank you for pointing this out. We have added implication of the research in management and utilization grassland area in the future from line 332 to line 336.
Minor comments
Line 13-14: change into “Pearson coefficient diagram was used to analyze …..”
Response: Thank you for pointing this out. We have changed it.
Line 205: please check and re write again the caption in more clarity. In for fig 4. Is the simulation A-F or A-E as explained in table 1?
Response: We apologize for the oversight. We have checked all the caption and changed the mistakes. In for fig 4, the simulation A-E is as explained in table 1. We have modified the table 1 caption and fig 4 caption. Thank you!
Line 218-219: please check again, is fig 5d represent CO2 and temperature increase? as table 1, this should represent simulation C
Response: Thank you for your careful review. Fig 5d represent simulation C, so we changed to “increasing precipitation” in line 219. Sorry for the mistake.
Line 220-221: similar to previous comment, please check again, should this fig 5e represent simulation D?
Response: Yes, the fig5e represent simulation D, so we changed to “increasing temperature and precipitation” in line 220-221, thank you so much!
Line 221: decrease in SOC
Response: Thanks a lot, we have changed it.
Line 240: Check again legend of map in figure 6. duration of simulation 2019-2048 or 2019-2044?
Response: The duration of simulation is 2019-2048, we have checked all the manuscript and make sure it. Thank you for your careful review.
Line 306: similar to previous comment, is this correct 2019-2048?
Response: 2019-2048 is correct, thanks a lot.
Thank you for your constructive comments and suggestions. We believe they have contributed immensely to the quality of our manuscript.
Author Response File: 
Author Response.docx
Reviewer 2 Report
This is an interesting paper showing spatiotemporal variations of grassland soil organic carbon (SOC) in response to five climate scenario. The model in this study predicted decrease in SOC for 25 years regardless of applied climate scenario and showed a dominant impact of temperature on SOC.
My principal concern is with one of the main results to show temporal changes of SOC in different scenario. First, there’re no uncertainty for each prediction in Figure 3, which make it hard to show the difference among the scenarios. The baseline covers up to 2018 and the five future predictions starts in 2019. However, the end values from the baseline (ca. 4000) is too low compared to the starting values of the five future predictions (ca. 5600). In lines 147-151, the authors mentioned increases of SOC in A and C but I was not able to find these increase of SOC in the corresponding figure. Is this decreases and increases indicates values other than the changes of SOC from 2019 to 2044? Are these rates of change?
In the abstract and conclusion sections, the paragraphs were hard to read and focused too much on listing results. Adding statements to show what the simulation results may imply would be more helpful for readers to understand the objectives and novelty of this study. I also suggest avoiding repeating detailed results (e.g. numbers) in conclusion.
In the results section, some of figures are hard to interpret and may be more appropriate as supporting information. For example, figure 4 includes 24 panels of heatmap and it’s really hard to capture the idea or values that the authors wanted to deliver. I suggest to move it to supporting information. Or, is it possible to modify the figure to show normalized (by baseline) value and/or in response to one factor (CO2, temp, precipitation) at a time (e.g. A vs B for temperature effect).
Figure captions does not include sufficient information for readers. For example, in figure 5, it is unclear what the colors and values mean in the map. Does red mean smaller decline of precited SOC? If it is, between what years? Figure 6 is extremely hard to read. The bar charts does not provide any information.
Minor comments:
L11: remove ‘Next,’
L13-14: The sentence starting with ‘Meanwhile,’ is incomplete.
L15: remove stat results from abstract.
L31: ‘carbon’ was mentioned already and seemed to be used more later. Need to choose between ‘carbon’ and ‘C’, and use consistently.
L40-43: too long sentence and the idea is unclear.
L88-90: The sentence needs to be revised.
Figure 2: add 1:1 line
L142: What dose each symbol means in the plot?
L142: use lower case ‘p’ for ‘predicted’
L153-156: any evidence to support the relationships with temperature or precipitation?
Fig. 7: need more info in the caption. What are the shapes? What are the colors?
L269-272: Too long sentence.
L280-282: sentence not completed.
L302: What does ‘good simulation effect’ mean?
Author Response
Response to Reviewer 2 comments
General Comments
Point 1: This is an interesting paper showing spatiotemporal variations of grassland soil organic carbon (SOC) in response to five climate scenarios. The model in this study predicted decrease in SOC for 25 years regardless of applied climate scenario and showed a dominant impact of temperature on SOC.
Response 1: Thank you so much for your constructive comments and time!
Point 2: My principal concern is with one of the main results to show temporal changes of SOC in different scenario. First, there’re no uncertainty for each prediction in Figure 3, which make it hard to show the difference among the scenarios. The baseline covers up to 2018 and the five future predictions starts in 2019. However, the end values from the baseline (ca. 4000) is too low compared to the starting values of the five future predictions (ca. 5600). In lines 147-151, the authors mentioned increases of SOC in A and C but I was not able to find these increase of SOC in the corresponding figure. Is this decreases and increases indicates values other than the changes of SOC from 2019 to 2044? Are these rates of change?
Response 2: Thank you for your careful review. In Figure 3, There is no uncertainty in each forecast because we judge and eliminate the abnormal values in the data in the process of processing the data, which makes the content of SOC value in each scenario have small differences in different years and different quarters. The research period is from 1989-2018 and 2019-2048, we have added the 2018 and 2048 on the x axis in Figure 3, thanks! The final value of the baseline in 2018 is about 4,000, and the five future predicted values from 2019 are about 5,600. This is because we use the future climate scenarios from 2019, there may be some deviation in the future predicted values, which is also mentioned in the uncertainty analysis of the article. In lines 147-151, The increase of Scenario A and Scenario C is relative to the baseline, we have changed it in the manuscript, thanks a lot for your careful review. Thank you so much for your insightful suggestions.
Point 3: In the abstract and conclusion sections, the paragraphs were hard to read and focused too much on listing results. Adding statements to show what the simulation results may imply would be more helpful for readers to understand the objectives and novelty of this study. I also suggest avoiding repeating detailed results (e.g. numbers) in conclusion.
Response 3: Thank you so much for your suggestions! We have modified the abstract and conclusion as you suggest, thanks a lot!
Point 4: In the results section, some of figures are hard to interpret and may be more appropriate as supporting information. For example, figure 4 includes 24 panels of heatmap and it’s really hard to capture the idea or values that the authors wanted to deliver. I suggest to move it to supporting information. Or, is it possible to modify the figure to show normalized (by baseline) value and/or in response to one factor (CO2, temp, precipitation) at a time (e.g. A vs B for temperature effect).
Response 4: Thank you so much for your suggestions! We have moved the figure 4 to supplement.
Point 5: Figure captions does not include sufficient information for readers. For example, in figure 5, it is unclear what the colors and values mean in the map. Does red mean smaller decline of precited SOC? If it is, between what years? Figure 6 is extremely hard to read. The bar charts does not provide any information.
Response 5: Thank you for pointing this out. We apologize for the oversight. We have checked all the figure captions and make sure its suitable. In figure 5, the values mean the annual average grassland SOC, the colors represent the level of soil organic carbon, red mean smaller decline of precited SOC, it’s the average value of the research period.
Minor comments:
L11: remove ‘Next,’
Response: Thanks, we have removed it.
L13-14: The sentence starting with ‘Meanwhile,’ is incomplete.
Response: We have modified the sentence to “Meanwhile, Pearson coefficient diagram was used to analyze the main influencing factors of SOC”. Thanks a lot!
L15: remove stat results from abstract.
Response: We have removed it, many thanks!
L31: ‘carbon’ was mentioned already and seemed to be used more later. Need to choose between ‘carbon’ and ‘C’, and use consistently.
Response: Thank you for pointing this out. We changed all the “C” to “carbon” to make it consistent.
L40-43: too long sentence and the idea is unclear.
Response: Thank you for your careful review. We have deleted the “which is because rising temperature itself may produce carbon sources“ from the sentence, thanks!
L88-90: The sentence needs to be revised.
Response: We have revised it, please see the revised manuscript, thanks a lot!
Figure 2: add 1:1 line
Response: The 1:1 line has been added in Figure 2, thanks!
L142: What dose each symbol means in the plot?
Response: The x axis represents the observed SOC, and the y axis represents the predicted SOC, thanks for your questions!
L142: use lower case ‘p’ for ‘predicted’
Response: Thank you for your careful review. We have changed it.
L153-156: any evidence to support the relationships with temperature or precipitation?
Response: We apologize for the oversight. There’s no evidence to support the relationships with temperature or precipitation from Figure 3, so we deleted the sentences, thanks!
Fig. 7: need more info in the caption. What are the shapes? What are the colors?
Response: We have added the shapes and colors information in the Figure caption, thanks for your advice.
L269-272: Too long sentence.
Response: Thank you for your advice. We have modified the sentences as “This is mainly due to warming, which increased soil respiration and causes significant loss of SOC [25], it was consistent with the study of Volk et al. [26]”.
L280-282: sentence not completed.
Response: We have added “concentration rise” at the end of the sentence, many thanks!
L302: What does ‘good simulation effect’ mean?
Response: Sorry for our poor English level, we have changed it to “the CENTURY model has a good simulation result”, many thanks for your time and patients!
Thank you for your candid comment. We are grateful for your constructive comments, insightful suggestions and
Author Response File: Author Response.docx
Reviewer 3 Report
Dear authors,
Your manuscript provides a clean, straightforward analysis of the SOC spatial distribution under different climate changes across the envisaged timeframe. The methodology is well presented and offers the possibility to be rolled-out in future studies.
I would like to recommend that you expand the Discussion section to provide more details on the shortcomings of your methods and ways to address these.
Author Response
Response to Reviewer 3 comments
Dear authors,
Your manuscript provides a clean, straightforward analysis of the SOC spatial distribution under different climate changes across the envisaged timeframe. The methodology is well presented and offers the possibility to be rolled-out in future studies.
I would like to recommend that you expand the Discussion section to provide more details on the shortcomings of your methods and ways to address these.
Response: Thank you for your constructive comments and suggestions. We have added more details on the shortcomings in the discussion, just like “This study only applies to human beings during parameterization animal grazing, fertilization, and irrigation activities were simply regulated, and other human activities are not considered in this article.”, please see line 303-314 for the detail, thanks!
Author Response File: Author Response.docx
