Effects of Snow Cover on Carbon Dioxide Emissions and Their δ¹³C Values of Temperate Forest Soils with and without Litter

Round 1

Reviewer 1 Report

The authors studied effects of snow-cover and litter removal of soil heterotrophic respiration and 13C values of soil-respired CO2 in non-growing and growing seasons using lab simulation method and found that their effects vary with seasons and differ between the soil cores of BKPF and WBF.  These results help us to better understand how climate change induced snow cover change affect soil CO2 emission and decomposition of different types of organic matters. This paper is generally well written. 

The main issues are that the abstract and conclusions are too long. Please condense each of them into 200 to 300 words. In addition, Figure 6 could be interpretated in different ways as the R2 values are too low and some points in the figures can be considered as outliers. The correlations between CO2 and CO2-derived C13 have limited prediction capacity. 

 

English needs editing. For examples, Lines 364, 517, 604. Lines 364-367 should be deleted. 

Author Response

 

The authors studied effects of snow-cover and litter removal of soil heterotrophic respiration and 13C values of soil-respired CO2 in non-growing and growing seasons using lab simulation method and found that their effects vary with seasons and differ between the soil cores of BKPF and WBF. These results help us to better understand how climate change induced snow cover change affect soil CO2 emission and decomposition of different types of organic matters. This paper is generally well written. 

 

Responses: Thanks due to the reviewer’s encouragement.

 

The main issues are that the abstract and conclusions are too long. Please condense each of them into 200 to 300 words. In addition, Figure 6 could be interpretated in different ways as the R2 values are too low and some points in the figures can be considered as outliers. The correlations between CO2 and CO2-derived C13 have limited prediction capacity. 

 

Responses: Both abstract and conclusion are moderately revised. Figure 6 shows relationships between CO₂ emissions from snow-covered large forest soil columns and their corresponding δ¹³C values in the presence and absence of litter during the whole incubation. Under experimental conditions, the δ¹³C values of soil-respired CO₂ had a relatively large variability when the soil CO₂ emissions were less than 1.0 mmol CO₂ m^-2 s^-1. The large variability in the δ¹³C-CO₂ values would make the correlations between soil CO₂ emissions and their δ¹³C values more complicate. In fact, besides soil CO₂ emissions, air temperature and air humidity as well as soil properties would have impacts on the δ¹³C values of soil-respired CO₂. Some necessary field observations over the year should be done in the future to explore the critical intrinsic influencing mechanisms, by moderately considering the functions of soil physicochemical and microbial properties as well as priming effects caused by fine root biomass in regulating the δ¹³C of soil respiration and soil C dynamics. These contents have been mentioned in the section 5: Conclusion and future perspectives.

 

English needs editing. For examples, Lines 364, 517, 604. Lines 364-367 should be deleted. 

 

Responses: Thanks again due to the reviewer’s comments. These contents have been revised or removed in the revised version of this manuscript.

 

 

Author Response File: Author Response.docx

Reviewer 2 Report

I have read the article titled “Effects of snow cover on carbon dioxide emissions and their 13C values of temperate forest soils with and without litter”. The English of the article is moderate level and needs revision with the grammatical rules. And some physical misusage was detected. But, I realized that there were minor problems with the writing of this article. However, if these minor problems are resolved and rewritten and designed by answering the questions, I think that the article will be very important and contribute to the literature. Also, I added some minor suggestions in the PDF file.

 

Title

The title is good and illustrated the study.

Abstract

Written well, but it is too long and the last sentence needs to mention your study's key points.

 

Introduction

There is also a grammatical problem here. Some important sentences should be cited from more recent studies. I think a better literature review is needed in this part.

Material and Method

There is also a grammatical problem here. Some physical and chemical properties of soils affect the amount of carbon storage in soils. Therefore, some of these properties, especially pH, pH class, soil texture, clay type and percentage should be known. Information about these features is required.

Results

This section of the manuscript is clear, relevant, and presented well. But, there is also a grammatical problem here.

Discussion

This section of the manuscript is clear, relevant, and presented well but the manuscript needs to be discussed with the most recent studies on the side of clear, relevant and presented well. And, there is also a grammatical problem here.

Conclusion

A sufficient conclusion has not been reached about the importance of this study for now and for the future. This part should be revised.

The figures/tables/images/schemes are appropriate and they are properly showing the data. And, I would like to see the study site map.

Overall, this article has a very good research topic in terms of a soil carbon budget and increasing soil C storage capacity. however, some important points that I have mentioned need to be clarified. I believe that when these deficiencies are eliminated, this paper will make great contributions to the literature.

I would like to reconsider after minor revision in line with the recommendations.

 

 

Comments for author File: Comments.pdf

The English of the article is moderate level and needs revision with the grammatical rules.

Author Response

I have read the article titled “Effects of snow cover on carbon dioxide emissions and their 13C values of temperate forest soils with and without litter”. The English of the article is moderate level and needs revision with the grammatical rules. And some physical misusage was detected. But, I realized that there were minor problems with the writing of this article. However, if these minor problems are resolved and rewritten and designed by answering the questions, I think that the article will be very important and contribute to the literature. Also, I added some minor suggestions in the PDF file.

Responses: Thanks due to the reviewer’s encouragement. The manuscript has been revised by fully considering the comments or corrections by the reviewer.  

 

Title

The title is good and illustrated the study.

Responses: Thanks!

 

Abstract

Written well, but it is too long and the last sentence needs to mention your study's key points.

Responses: Thanks! This abstract is refined, and the key points of this study are mentioned.

 

Introduction

There is also a grammatical problem here. Some important sentences should be cited from more recent studies. I think a better literature review is needed in this part.

Responses: This section is moderately revised by considering more recent studies. Some new references are added in this section and other parts of this manuscript. New references are shown at the bottom:

1. Wu, J.B.; Guan, D.X.; Wang, M.; Pei, T.F.; Han, S.J.; Jin, C.J. Year-round soil and ecosystem respiration in a temperate broad-leaved Korean Pine forest. Ecol. Manage. 2006, 223, 35–44.
2. Liu, X.P.; Dong, W.X.; Wood, J.D.; Wang, Y.Y.; Li, X.X.; Zhang, Y.M.; Hu, C.S.; Gu, L.H. Aboveground and belowground contributions to ecosystem respiration in a temperate deciduous forest. For. Meteorol. 2022, 314, 108807.
3. Guo, N.; Lv, S.J.; Lv, G.Y.; Xu, X.B.; Yao, H.Y.; Yu, Z.H.; Qiu, X.; Wang, Z.Y.; Wang, C.J. Effects of warming and precipitation on soil CO₂ flux and its stable carbon isotope composition in the temperate desert steppe. Sustainability 2022, 14, 3351.
4. Phillips, C.L.; Nickerson, N.; Risk, D.; Kayler, Z.E.; Anderson, C.; Mix, A.; Bond, B.J. Soil moisture effects on the carbon isotope composition of soil respiration. Rapid Commun. Mass Sp. 2010, 24, 1271–1280.
5. Babur E., Dindaroglu, T.; Danish, S.; Haggblom, M.M.; Ozlu, E.; Gozukara, G.; Uslu, O.S. Spatial responses of soil carbon stocks, total nitrogen, and microbial indices to post-wildfire in the Mediterranean red pine forest. Environ. Manage. 2022, 320, 115939.

 

Material and Method

There is also a grammatical problem here. Some physical and chemical properties of soils affect the amount of carbon storage in soils. Therefore, some of these properties, especially pH, pH class, soil texture, clay type and percentage should be known. Information about these features is required.

Responses: This M&M section is moderately revised to reduce the similarity. Main soil properties such as pH, texture, soil organic matter, and bulk density as well as the properties of aboveground litter were described by Xu et al. [45,46] and Wu et al. [19,42].

 

Results

This section of the manuscript is clear, relevant, and presented well. But, there is also a grammatical problem here.

Responses: This results section is moderately revised by fully considering the reviewer’ comments and corrections.

 

Discussion

This section of the manuscript is clear, relevant, and presented well but the manuscript needs to be discussed with the most recent studies on the side of clear, relevant and presented well. And, there is also a grammatical problem here.

Responses: This discussion section is moderately revised by fully considering the reviewer’ comments and corrections. Some additional references are added in this section to give further discussion about the relationships of the δ¹³C values of soil-respired CO₂ and soil moisture. Further studies in the future will be mentioned at the end of this section.

 

Conclusion

A sufficient conclusion has not been reached about the importance of this study for now and for the future. This part should be revised.

Responses: This discussion section is moderately revised. Further studies in the future are mentioned in this section.

 

The figures/tables/images/schemes are appropriate and they are properly showing the data. And, I would like to see the study site map.

Responses: Map of the study site is shown in supplementary materials (please see Figure S1).

 

Overall, this article has a very good research topic in terms of a soil carbon budget and increasing soil C storage capacity. however, some important points that I have mentioned need to be clarified. I believe that when these deficiencies are eliminated, this paper will make great contributions to the literature.

I would like to reconsider after minor revision in line with the recommendations.

Responses: Thanks again due to the reviewer’s encouragement. The manuscript has been revised by fully considering the recommendations or corrections by the reviewer.