Influence of Phoebe bournei (Hemsl.) Replanting on Soil Carbon Content and Microbial Processes in a Degraded Fir Forest
Round 1
Reviewer 1 Report
Comments and Suggestions for Authors"Phoebe bournei (Hemsl.) Yang replanting in degraded Chinese fir forests enhances soil carbon content by reducing soil phosphorus content" is a good presentation of cluster of related data. However few quarries to be answered carefully.
1. "Chinese fir forests enhances soil carbon content by reducing soil phosphorus content", this thing is very loosely described. The C: N: P: S stoichiometry is an important factor for soil fertility and productivity; then redistribution of N and P due to replanting is only reason?
2. If possible please provide soil information (initial condition ) for U, S1, S2, S3.
Author Response
Dear reviewer1
We reorganized the figure1 and 2 to make them more readable according to your valuable suggestions, Thanks a lot.
Reviewer 2 Report
Comments and Suggestions for AuthorsI reviewed the article “Phoebe bournei (Hemsl.) Yang replanting in degraded Chinese fir forests enhances soil carbon content by reducing soil phosphorus content" and I found it sufficiently well prepared. Research conducted by the Authors was prepared in comprehensive manner. Provided manuscript was interesting to read. Conceptualization was done accordingly to proper manners in agronomy sciences which I find vital. Presentation of the results is on a high level. Still, the topic cannot be regarded as the one of global importance. In spite of that, the background was nicely introduced in pinpointing crucial problems that need to be solved. Methods selected by the authors have been properly chosen according to the actual state of knowledge but it’s description needs some corrections. As for the results section, it is worth mentioning that obtained results are indeed scientifically valuable. Descriptive presentation of obtained outcomes is pleasant to read and easy to understand. There are some minor corrections that have to be implemented before recommending the manuscript to be published. Overall, provided paper can be surely recommended to publication after minor revision, mostly in M&M section.
In details, it should be stated that the study methods were selected appropriately to the given research goal. The methodology itself will allow to recreate the conditions of the conducted experiment if the authors complete missing information. Altogether novelty and significance of content as well as scientific soundness of the manuscript are on a proper, level. Unfortunately the opportunity to highlight future key-needed research were not fulfilled at all. This should be corrected.
Please see detailed review below:
Title:
I strongly advice to rephrase the title to give it more focus on carbon turnover instead of indicating debatable causation between soil phosphorous reduction and carbon stock increase. Something like: “Influence of Phoebe bournei Replanting on Soil Carbon Sequestration and Microbial Processes in a Degraded Fir Forest” convey the research message much better than the initial title.
Introduction:
The research background and aims were presented clearly and transparently. It is clear which topics had to be broaden in order to enrich scientific knowledge. Given reasoning is easy to follow which makes the perception of the introduction very positive.
In my opinion this section doesn’t need any corrections.
Materials and Methods:
This section was written nicely. It is easy to read and comprehend most of given subsections.
[98-100] I strongly advice to use actual climate classification i.e. Koppen with a proper abbreviation for better reader’s comprehension of the study climatic zone.
[110] Does the transport was done at 4°C? Or was it lab temperature. It is not clear for me.
[128-130] This method should be described in more elaborative way.
[144-150] There is no mention of PCA analysis done in the statistical analysis description despite utilizing this method (i.e. Figure 3). Please correct that.
Results
I have positive feelings after reading the results section. The descriptive part of the section significantly completes presented data. I see no flaws
Discussion
Discussion section was written properly. It has to be said that the presented statements follow the reasoning from previous section. It is also understandable why and what authors wanted to explain here. The chance to enrich the scientific knowledge with critical discussion using properly chosen references was used to the fullest.
Conclusions
The conclusions result directly from the authors findings and are supported by the discussion section, which is proper. Unfortunately, the opportunity to inform about the future research demands was not fulfilled. This should be corrected.
Author Response
Dear reviewer2:
We sincerely thank your patient and careful review work on our manuscript, especially the remind of highlighting the future key-needed research work, which improved this paper a lot. And we will respond to your detailed corrections and suggestions one by one in the following part.
Title:
I strongly advice to rephrase the title to give it more focus on carbon turnover instead of indicating debatable causation between soil phosphorous reduction and carbon stock increase. Something like: “Influence of Phoebe bournei Replanting on Soil Carbon Sequestration and Microbial Processes in a Degraded Fir Forest” convey the research message much better than the initial title.
Response:
Wow! We can not say more appreciation for the title you selected for our manuscript, and we had changed the title accordingly.
Materials and Methods:
[98-100] I strongly advice to use actual climate classification i.e. Koppen with a proper abbreviation for better reader’s comprehension of the study climatic zone.
Response: We had changed the sentence to “The site is humid and is in a mid-subtropical zone” according to the suggestion.
[110] Does the transport was done at 4°C? Or was it lab temperature. It is not clear for me.
Response: Thanks for the reminds, we changed it as “then stored under 4°C.”
[128-130] This method should be described in more elaborative way.
Response: Thanks, we added “The 5g of soil sample (dry weight) was added to 50ml bottle, then 1ml methylbenzene, 5ml disodium benzene phosphate (6.75g dissolved in 1L water) and 5ml NaAc-HAc buffer (pH 5.0) were added and evenly mixed. Another control sample were added by water instead of the mixed solution. After a 24h 37°C incubation, the mixed soil and solution were filtrated. 1ml of filtrated solution was transferred to 100ml bottle, added with 5ml pH 9.0 boric acid buffer, 3ml 2.5% potassium ferricyanide and 3ml 0.5% 4- aminoantipyrine. After even mixing, the solution was measured colorimetric under 570nm by a Ultraviolet photometer (Shimatsu, UV1900i).”
[144-150] There is no mention of PCA analysis done in the statistical analysis description despite utilizing this method (i.e. Figure 3). Please correct that.
Response: Thanks, we corrected it as “Using the online platform https://cloud.majorbio.com (accessed on 20 May 2023), the Richness, Shannon index, the analysis of similarities among microbial communities (PERMENOVA) and the principal coordinates analysis (PCoA) based on Bray-Curtis distances at OTU-level were all conducted.”
The conclusions result directly from the authors findings and are supported by the discussion section, which is proper. Unfortunately, the opportunity to inform about the future research demands was not fulfilled. This should be corrected.
Response: Thanks, We added “The future studies will further explore the effects of replanting on SOM of degraded forest, especially focusing on the changes in MAOM and POM composition distributed on soil profile and aggregate structures, and resolving the relationship to microbial communities, these results will offer a comprehensive understanding on the micro-ecological mechanism of carbon sequestration in forest on red soil region and provide theoretical guidance for enhancing soil carbon sink of degraded forests.”
Lastly, we thanks again for the valuable correction and suggestion you offered for us.
Author Response File: 
Author Response.docx
Reviewer 3 Report
Comments and Suggestions for AuthorsThe topic is relevant and interesting. The manuscript is quite well prepared. After minor corrections, it is fit for publication.
It is necessary to change the font size of the letters and numbers in Figure 1 and Figure 2. The current size is unreadable.
Author Response
Dear reviewer3:
Thanks for your scientific and helpful reminds, and we’ll respond to the two comments.
- "Chinese fir forests enhances soil carbon content by reducing soil phosphorus content", this thing is very loosely described. The C: N: P: S stoichiometry is an important factor for soil fertility and productivity; then redistribution of N and P due to replanting is only reason?
Response: Thanks for the valuable suggestion, coupled with the suggestion from reviewer2, we changed the title accordingly. A relatively balancing stoichiometry as well as a sufficient nutrient content are the key to most terrestrial ecosystems, so just as you mentioned, the N and P limitation might not the only reason for the soil carbon accumulation. The enhanced primary productivity, the less run-off offered by the higher shelter, and other possible factors introduced by replanting, are all potential contributor to the SOM accumulation. Yet, in this paper, we mainly focusing on the microbial process and N and P limitation variation.
- If possible please provide soil information (initial condition) for U, S1, S2, S3.
Response: I feel sorry that we can’t, as we used a space for time method, and didn’t sample the soil sample of original (initial condition) state. This really reminds us the importance of long-term observation, and we’ll fixed this problem in the future research.
Thanks again for your helpful suggestions.
Reviewer 4 Report
Comments and Suggestions for Authors
Phoebe bournei (Hemsl.) Yang replanting in degraded Chinese fir forests enhances soil carbon content by reducing soil phosphorus content
In general, land or soil degradation even under forest condition is very important topic and replanting the tree is crucial strategy against this situation.
Furthermore, long term studies is very vital for this topic as well, but this study needs more major concern to be ready for publication:
- Keywords: please do not use any word already mentioned in the title
- Introduction section, please needs to apply update refs. (mainly 2024, 2023, 2022, 2021) or even the last 5-7 years, please
Please the whole MS must include update refs. may be within the last 10 years not more as you can
- Introduction section needs a paragraph on soil (land) degradation, which should include cause, impacts, its mitigation
- Materials sections, in Table 1, please mention details on all symbols (abbreviations) a, U, and S in the footnote of this table
- the authors measured Soil total phosphorus/or nitrogen content, why you did not measure available to be more fit parameter in soil handling?
- first impression, please add a table to include the basic soil parameters for studied areas including soil pH, EC, texture, available nutrients (mainly NPK and others)
- a flowchart is needed please to explain the amin treatments, measurement and some photos for these locations are needed, please
- Results section:
Very general comment, please a text must be mentioned first and then a Table or a Figure comes later as possible. Not accepted to start any section or part in your MS with figure or table, please
- Figure 1, why the red dotted line of threshold was not in all figures?
- what does mean “Variation in soil enzyme activity” Figure 2 did not explain that
I mean as a long-term study; authors need to explain (not this figure) the variation rate of each parameter by time
- Figure 31. (d) please not that values of soil pH cannot follow statistical analyses, these are not real values (- log) please remove these letters on each column
Major revision is needed
Comments on the Quality of English Language
minor edits
Author Response
Dear reviwer4:
We sincerely thank you for the valuable and scientific suggestions and corrections offered, they tough us a lot and helped improving the quality of this manuscript. And we’ll respond to them one by one.
- Keywords: please do not use any word already mentioned in the title
Response: We changed the title as “Influence of Phoebe bournei (Hemsl.) Replanting on Soil Carbon Content and Microbial Processes in a Degraded Fir Forest”, and changed the keywords as “degraded forest; soil phosphorus limitation; soil carbon; microbial community; replantation”
- Introduction section, please needs to apply update refs. (mainly 2024, 2023, 2022, 2021) or even the last 5-7 years, please
Please the whole MS must include update refs. may be within the last 10 years not more as you can
Response: We added several newly published references, Such as “Zhou H, Ma A, Zhou X, Chen X, Zhang J, Zhang Q, Qi X, Liu G, Zhuang G: Phosphorus shapes soil microbial community composition and network properties during grassland expansion into shrubs in Tibetan dry valleys. Frontiers in Plant Sciences 2022, 13.
Kpemoua TPI, Leclerc S, Barré P, Houot S, Pouteau V, Plessis C, Chenu C: Are carbon-storing soils more sensitive to climate change? A laboratory evaluation for agricultural temperate soils. Soil Biology and Biochemistry 2023, 183:109043.” We hope some classic references from nature, science and PNAS could be remained, as they may suggest our idea more powerfully.
- Introduction section needs a paragraph on soil (land) degradation, which should include cause, impacts, its mitigation
Response: Thanks for the important suggestion, we added a paragraph as “Generally, the forest degradation may be attributed to the pollution, overly afforestation or unreasonable fertilization caused by anthropogenic activities. The soil nutrient depletion, pathogen and disease, and the death due to climate change were also reported as main reasons for forest degradation. Chinese fir forest degradation was mainly caused by long-term consecutive monoculture, resulting in reduced soil fertility, decreased primary productivity, and less soil organic matter accumulation. This issue cannot be solved solely by using chemical fertilizers, and microbial communities may hold the key to mitigating degradation. Replanting broadleaf trees in degraded fir forests has been reported to help mitigate monoculture-induced degradation,”
- Materials sections, in Table 1, please mention details on all symbols (abbreviations) a, U, and S in the footnote of this table
Response: We add the footnote according to the reminds, thank you so much.
- the authors measured Soil total phosphorus/or nitrogen content, why you did not measure available to be more fit parameter in soil handling?
Response: We also measured several available nutrients, such as available phosphorus and alkaline-hydrolytic nitrogen in figure1, and we had added new figure capture so that the reader can catch the indicators more clearly.
- first impression, please add a table to include the basic soil parameters for studied areas including soil pH, EC, texture, available nutrients (mainly NPK and others)
Response: We feel sorry that we can not offer some basic soil parameters of this area, as we didn’t measure them before, like EC and texture, available potassium. Unfortunately, hardly can we make a supplementary measurement because the samples had been disposed before. We use “space for time”, not long-term observation, and we thought that the soil properties of “U” should be the “original properties”, this is really a flaw, thanks for your review, it led us a clearer understanding on future field sampling and testing.
- a flowchart is needed please to explain the amin treatments, measurement and some photos for these locations are needed, please
Response: We had added the sampling sites photos and work flowchart as figure 1, thanks for the suggestion, which lead our work more readily to be understood by readers.
- Results section:
Very general comment, please a text must be mentioned first and then a Table or a Figure comes later as possible. Not accepted to start any section or part in your MS with figure or table, please
Response: We had reorganized the location of figures, thanks for the correction.
- Figure 1, why the red dotted line of threshold was not in all figures?
Response: Because the Redfield ratio is a ratio threshold of C:N:P, so it can not exit in content figures, but in ratio figures.
- what does mean “Variation in soil enzyme activity” Figure 2 did not explain that
I mean as a long-term study; authors need to explain (not this figure) the variation rate of each parameter by time
Response: Thanks for the suggestion. The figure 2 depicts the enzyme activities of different stages, we didn’t choose the variation rate to explain the variation, instead, we marked the detailed value of the enzyme activities of each stage, so the reader could directly get the change of enzyme activity caused by replanting time. Thus, we hope the figure2 could be maintained, but we changed the title of the figure as “Soil enzyme activity of different stages” according to the suggestion.
- Figure 31. (d) please not that values of soil pH cannot follow statistical analyses, these are not real values (- log) please remove these letters on each column
Response: We had deleted the error bars upon pH in figure1, thanks for your correction.
Lastly, we thank again for your help to this manuscript
Author Response File: Author Response.docx
Round 2
Reviewer 4 Report
Comments and Suggestions for Authorsmany thanks for your corrections
all the best
Comments on the Quality of English Languageit is ok
