Effects of Close-to-Nature Transformation on Soil Enzyme Activities and Organic Carbon Fractions in Cuninghamia lanceolata and Pinus massoniana Plantations

Round 1

Reviewer 1 Report

The topic of this paper is relevant, the data are important, and could be interesting to the international readership.

lines 105-115 - please revise this very long sentence; it should be divided into shorter ideas/sentences.

table 1 - the abbreviations CCK, CCN, etc. given in the table should be described next to the table.

what is the number of replications in your study? I van find only the information "A total of sampling points were randomly selected in the sample plot. The soil surface covering was removed, the 0-10cm soil sample was drilled by a soil drill with an inner diameter of 8.7cm..." but how many samples have you taken in the field? were they sampled each sample from one place or were they mixed? how have you selected the places for sampling - randomly or systematically? you have mentioned only 0-10 cm soil layer in Methods but in figure 1 there are also 10-30 and 30-50 cm soil layers. 

Table 2 - what kind of data is included here? is it from 0-10 cm layer? 0-50 cm??

what parameters do the authors show as "soil physical properties"? I see only chemical properties given in Chapter 3.1 and table 2.

lines 230-231 - when you talk about correlations, you should show the data in Chapter 3.4 better than in the Discussion part.

the abstract and conclusions should be shorter, more accurate and specific; do not try to repeat the results in the conclusions, but give insights derived from your results.

Overall, I liked this paper but still ask the authors to correct some places (given above, especially Methodological aspects), and also to reveal two issues: what was the hypothesis of this study and how, possibly, the results could be applied in practical forestry.

Author Response

Dear editor

 

Please find below our responses to the comments of the reviewers and explanations how we addressed the critical points. We are grateful for the very constructive suggestions, which certainly helped to improve our manuscript.

Below, you will find our responses in italics to the respective comments.

 

With best regards,

Weiwei Shu

On behalf co-authors

 

Responses to Reviewer # 1 ##

The topic of this paper is relevant, the data are important, and could be interesting to the international readership.

lines 105-115 - please revise this very long sentence; it should be divided into shorter ideas/sentences.

Re: Thank very much for the comments and suggestions, which is quite helpful to improve our manuscript. The long sentence has been modified into short sentences as suggested.

table 1 - the abbreviations CCK, CCN, etc. given in the table should be described next to the table.

Re: Describe in the figure and table as suggested.

what is the number of replications in your study? I van find only the information "A total of sampling points were randomly selected in the sample plot. The soil surface covering was removed, the 0-10cm soil sample was drilled by a soil drill with an inner diameter of 8.7cm..." but how many samples have you taken in the field? were they sampled each sample from one place or were they mixed? how have you selected the places for sampling - randomly or systematically? you have mentioned only 0-10 cm soil layer in Methods but in figure 1 there are also 10-30 and 30-50 cm soil layers.

 Re: Corrected as suggested. In total, 144 soil-sampling points were randomly selected within the 16 sampling plots in each of the 4 stands. Nine soil core samples were collected from each plot at depths of 0–10, 10–30 and 30–50 cm. They were then combined according to soil depth. See 2.3. Samplings and measurements.

Table 2 - what kind of data is included here? is it from 0-10 cm layer? 0-50 cm??

what parameters do the authors show as "soil physical properties"? I see only chemical properties given in Chapter 3.1 and table 2.

 Re: It is our carelessness. There is no physical property in Table 2 and it has been corrected. See the header description in Table 2

lines 230-231 - when you talk about correlations, you should show the data in Chapter 3.4 better than in the Discussion part.

Re: Corrected as suggested.

the abstract and conclusions should be shorter, more accurate and specific; do not try to repeat the results in the conclusions, but give insights derived from your results.

Re: You are right about this part. We have refined the abstract part. See abstract.

Overall, I liked this paper but still ask the authors to correct some places (given above, especially Methodological aspects), and also to reveal two issues: what was the hypothesis of this study and how, possibly, the results could be applied in practical forestry.

Re: Here we added hypothesis. We hypothesized that: (1) CNT can increase soil organic carbon and stability; (2)The change of soil organic carbon was regulated by enzyme activity.

 

 

Author Response File: Author Response.docx

Reviewer 2 Report

General

The manuscript titled “Effects of soil enzyme activities and organic carbon fractions 2 after close-to-nature transformed plantations of Cuninghamia lanceolata and Pinus massoniana” investigates high number of soil variables in two types of treated and untreated plantations. The study works on interesting and actual problem, however, I think that the Authors grasp all and lose all.

I suggest to the Authors to reconsider the whole concept of this manuscript. I think there are two large issues here and it is too difficult and extensive to process all of them. The Authors should first reveal the relationships among soil properties, and after that, the most important properties and relationships can be used to reveal the effects of “close-to-nature” transformation on soil properties.

Detailed comments

Title

Cuninghamia lanceolate

I miss the object from the title. Effects of something on what?

 

Abstract

Too long and wordy.

The introduction part is too long.

I miss the material and methods part. I see that it is the sentence of lines 18-21 but it is too superficial.

You should find out the most important 4-5 results and write them into the Abstract. The results part is too wordy and reflects that the Authors do not know, what is really important among the many results.

 

Introduction

(You find later, that many pieces of information taken place in the Discussion section, should be transferred into the Introduction section.)

Lines 47-56: Where are the references? All the known statements needs a reference. This information is not originated from the Authors, as I think.

Line 60 better that what?

Line 75: has changed: compared to what?

Line 78: “Previous studies indicated” Avoid these noise words.

Line 80: “Some studies also showed”: noise words…

Line 84: change? After what?

Line 88-89: not rather mineralizing and decomposing enzymes?

Line 99-101: Reconsider this sentence.

Line 101 to improving?

 

Materials and methods

When were the samples taken?

How many samples were taken?

You didn’t mention the different soil levels in this section but in the Results section , all the results were from three soil layers.

It is inacceptable that the methodology is described without real references. The paragraph (line 153-162) includes no references! It must be added.

The reference number 21 is also inacceptable. It is a book. The Authors should name the original literature of these methods.

Statistical analyses:

I missed the indication of number of samples.

I suggest to use general linear models, or two-way ANOVAs instead of many-many one-way ANOVAs. E.G pH ~ Plantation* Soil level. Then you have 10 models instead of 70 models having higher risk of false positive result. That is why it is very difficult to find out the important results from these many- many results.

Did the Authors make any model diagnostics?

Which R functions were used? With reference! R needs also reference!

 

Results

Line 191f Reconsider this sentence!

Tables and Figures: Add all abbreviations to the captions!

Line199: “It can be found that” leave it! Noise words again…

Line 202-203 Reword the sentence.

Line 205, 219: increases: Compared to what? Did you measure it earlier as well? It is not a process, it is just a state, what you compared in the same time! It did not increase but rather was higher than in the control.

Line 208: “change rule” What does it mean?

Lines 219, 230: “It is showed that” leave it! Noise words again…

Lines 243-245: these lines should belong to the Material and Methods section!

Figure 3: I suggest to display the samples indicating the four plantations, as well.

 

Discussion

My problem is that I think that the Authors did not decide that what is important for them. Is it about the relationship among soil chemical variables or is it about the effects of the “close-to-nature” transformation on these soil properties. Sometimes we can read about the previous topic then comes the other. That is why there is no logical chain of ideas. We can see it also in the Title: Effects of… Yes, effects of something but on what? On each other? Please, reconsider the all concept of the manuscript. In this state, it is too wordy and untraceable.

In addition, in chapter Discussion, we normally start with our main results. We repeat them shortly, and then, we compare them with other results and we discuss the conclusions. And then another results come, and another conclusions etc. Please, don’t start with known results. These parts should be taken into the Introduction or after your results. You should start with line 272.

Line 255f Reference?

Line 256-259. Reconsider this sentence. Effects of forest ecosystems?

Line 260. Too many of the word “transformation”.

Lines 259-268. I missed this part from the Introduction chapter. This part rather belongs to there.

Line 264: “Studies showed that” unnecessary words…

 Line 268: “The previous studies showed” unnecessary words…

Line 281: What do you mean “is not long”?

Line 281: What kind of difference?

Line 280: I suggest to compare the study durations among Your and the referred studies.

Line 288-290: it is also such information which should have been in Introduction.

Line 290. Start the paragraph with this sentence: “In this study…”

Line 292: I still do not like this word “increased”. You did not study a process but rather one state.

Line 293-294: Reference? Full stop?

I have a problem with this paragraph. The chain of ideas. First two sentences: two statements about WSOC. Then two sentences about the results. And then, another two sentences. They are in one paragraph, but I cannot find the chain of ideas. What did you want to tell us? These sentences are almost incoherent. Please, rethink it!

Line 297-302: Perfect starting and then an understandable argument. I liked it! I think something similar for the previous and following paragraphs.

Line 303 Difference of what?

Line 305f: Why?

Line 305-309: Can you refer to some studies from where these ideas may come? OR are these just your intuitions?

Line 310-312: take this sentence into the Introduction or take it after your results…

Line 314: Increased compared to what? In time? In space?

Line 316: Did you measure these variables, the litterfall and the decomposition? So, from where do you know it?

Line 314-318: Do you think you used an inadequate method to measure the particulate organic carbon?

Line 320-321. What do you think about the carbon pool and the soil fertility of the plantations? You mentioned, that the POC is a good indicator for these. What is the conclusion?

 

Line: 323-325. Into Introduction or into the arguing.

Line 330. Decrease? You didn’t know the starting values, did you? Then you know only differences between treated and untreated plantations.

Line: 328-333: I don’t understand this sentence. What do you mean that “basically consistent with the response of ROC”? ROC did not differ between PCK and PCN, so there was no “response”. The mentioned nutrient “decreased after” the treatment, but there was no difference between the plantations.

Line 336: Causing? Are you sure that soil carbon content changes because of the changes of soil physical and chemical characters? You found correlations, that’s all. It doesn’t mean causality.

Line 349-351: This is the same result as in lines 333f… You should summarize the results and explanations more effectively… The Discussion part is too long. You should point out the most important results and avoid redundancy like this.

Line 358: You previously discussed the different variables and their relations, and now comes the plantations… What is now important?

Line 367-371. Introduction or explanation…

Line 373-374: Increased again…

Line 396: Please, leave this: “it is found in the study”: if you refer to a study/article/work, it means the same. It is enough to write down the main result and then write the reference number [42]. That’s it.

Line 402 Why is it a problem that the samples were taken in the growing season?

 

Conclusion

A conclusion is a short and tight summary of the results and the consequences. Not a list of results. Please, reconsider this paragraph and reconsider the concept of the manuscript.

Author Response

Dear editor

 

Please find below our responses to the comments of the reviewers and explanations how we addressed the critical points. We are grateful for the very constructive suggestions, which certainly helped to improve our manuscript.

Below, you will find our responses in italics to the respective comments.

 

With best regards,

Weiwei Shu

On behalf co-authors

 

Responses to Reviewer # 2 ##

General

The manuscript titled “Effects of soil enzyme activities and organic carbon fractions 2 after close-to-nature transformed plantations of Cuninghamia lanceolata and Pinus massoniana” investigates high number of soil variables in two types of treated and untreated plantations. The study works on interesting and actual problem, however, I think that the Authors grasp all and lose all.

I suggest to the Authors to reconsider the whole concept of this manuscript. I think there are two large issues here and it is too difficult and extensive to process all of them. The Authors should first reveal the relationships among soil properties, and after that, the most important properties and relationships can be used to reveal the effects of “close-to-nature” transformation on soil properties.

Detailed comments

Title

Cuninghamia lanceolate

I miss the object from the title. Effects of something on what?

 Re: Corrected as suggested. We rephrase this title as “Effects of close to natural transformation on soil enzyme activities and organic carbon fractions in Cuninghamia lanceolata and Pinus massoniana plantations”.

Abstract

Too long and wordy.

The introduction part is too long.

I miss the material and methods part. I see that it is the sentence of lines 18-21 but it is too superficial.

You should find out the most important 4-5 results and write them into the Abstract. The results part is too wordy and reflects that the Authors do not know, what is really important among the many results.

  Re: Abstract has been modified according to the revision opinions. We reorganize the original too long results, select the important research results to four aspects, and on this basis, summarize and extract the research conclusions and suggestions related to forest management practice.

 (You find later, that many pieces of information taken place in the Discussion section, should be transferred into the Introduction section.)

Lines 47-56: Where are the references? All the known statements needs a reference. This information is not originated from the Authors, as I think.

Re: Reference has been added. See reference [2]and [3].

Line 60 better that what?

Re: Here we rephrased as” However, due to the high background value of soil organic carbon, the response to changes in the short-term management mode shows a certain lag, which cannot accurately reflect the change of soil quality and transformation rate in a short time”.

Line 75: has changed: compared to what?

Re: The comparison object refers to the pure forest that has not been transformed and managed in a traditional way.

Line 78: “Previous studies indicated” Avoid these noise words.

Line 80: “Some studies also showed”: noise words…

Re: Corrected as suggested.

Line 84: change? After what?

Line 88-89: not rather mineralizing and decomposing enzymes?

Re: This part is deleted and the relationship between organic carbon and enzyme activity is restated.

Line 99-101: Reconsider this sentence.

Line 101 to improving?

Re: Corrected as suggested. Here we rephrased as“Although the relationship between soil enzyme activities and soil organic carbon components has been widely concerned, what are the effects of close-to-nature transformation on soil organic carbon components and enzyme activities? Is it beneficial to improve soil carbon sequestration and stability of stand?” 

Materials and methods

When were the samples taken?

How many samples were taken?

You didn’t mention the different soil levels in this section but in the Results section , all the results were from three soil layers.

Re: In this part, we apologize for the confusion. Corrected as suggested. Soil samples were collected in August 2018 to determine soil chemical properties. In total, 144 soil-sampling points were randomly selected within the 16 sampling plots in each of the 4 stands. Nine soil core samples were collected from each plot at depths of 0–10, 10–30 and 30–50 cm. They were then combined according to soil depth. See 2.3. Samplings and measurements.

It is inacceptable that the methodology is described without real references. The paragraph (line 153-162) includes no references! It must be added.

Re: References 18, 19 and 20 have been added here.

The reference number 21 is also inacceptable. It is a book. The Authors should name the original literature of these methods.

Re: Thank very much for the suggestions. We consulted a lot of relevant literature, and the original literature of the detection method we used basically came from this book. Therefore, we did not replace the reference.

Statistical analyses:

I missed the indication of number of samples.

Re: Added as suggested. Total 144 soil samples. See 2.3. Samplings and measurements.

I suggest to use general linear models, or two-way ANOVAs instead of many-many one-way ANOVAs. E.G pH ~ Plantation* Soil level. Then you have 10 models instead of 70 models having higher risk of false positive result. That is why it is very difficult to find out the important results from these many- many results.

Did the Authors make any model diagnostics?

Re: Our focus is to explore the differences between the pure and close natural transformed .The indexes for comparison are mainly enzyme activity and carbon composition, while soil properties serve only as basic background indexes to understand and explain the differences between stands. Therefore, conventional one-way ANOVA was sufficient to satisfy this study.

Which R functions were used? With reference! R needs also reference!

 Re: Added as suggested.

Results

Line 191f Reconsider this sentence!

Re: Corrected as suggested. Here we rephrased as”However, no significant dierence was detected in the contents of all nutrients of P. massoniana and C. lanceolata between the close to natural and pure forests”. See 3.1. Soil physical and chemical properties

Tables and Figures: Add all abbreviations to the captions!

Re: Describe in the figure and table as suggested. CCK, CCN, PCK and PCN represent the pure and close natural transformed C. lanceolata plan-ta-tion and the pure and close natural transformed P. massoniana plantation, respectively.

Line199: “It can be found that” leave it! Noise words again…

Line 202-203 Reword the sentence.

Line 205, 219: increases: Compared to what? Did you measure it earlier as well? It is not a process, it is just a state, what you compared in the same time! It did not increase but rather was higher than in the control.

Re: Corrected as suggested.

Line 208: “change rule” What does it mean?

Re: We deleted it and replaced this words with “change law”.

Lines 219, 230: “It is showed that” leave it! Noise words again…

Re: Corrected as suggested.

Lines 243-245: these lines should belong to the Material and Methods section!

Re: We deleted the sentences

Figure 3: I suggest to display the samples indicating the four plantations, as well.

Re: We added the sample site in Figure 3 as suggested.

 Discussion

My problem is that I think that the Authors did not decide that what is important for them. Is it about the relationship among soil chemical variables or is it about the effects of the “close-to-nature” transformation on these soil properties. Sometimes we can read about the previous topic then comes the other. That is why there is no logical chain of ideas. We can see it also in the Title: Effects of… Yes, effects of something but on what? On each other? Please, reconsider the all concept of the manuscript. In this state, it is too wordy and untraceable.

In addition, in chapter Discussion, we normally start with our main results. We repeat them shortly, and then, we compare them with other results and we discuss the conclusions. And then another results come, and another conclusions etc. Please, don’t start with known results. These parts should be taken into the Introduction or after your results. You should start with line 272.

Line 255f Reference?

Line 256-259. Reconsider this sentence. Effects of forest ecosystems?

Line 260. Too many of the word “transformation”.

Re: This part has been modified according to the suggestion.

Lines 259-268. I missed this part from the Introduction chapter. This part rather belongs to there.

Re: References have been added to the introduction section。

Line 264: “Studies showed that” unnecessary words…

 Line 268: “The previous studies showed” unnecessary words…

Re: This part has been revised and adjusted

Line 281: What do you mean “is not long”?

Line 281: What kind of difference?

Line 280: I suggest to compare the study durations among Your and the referred studies.

Re: This section has been modified and time has been added.

 Line 288-290: it is also such information which should have been in Introduction.

Line 290. Start the paragraph with this sentence: “In this study…”

Line 292: I still do not like this word “increased”. You did not study a process but rather one state.

Line 293-294: Reference? Full stop?

I have a problem with this paragraph. The chain of ideas. First two sentences: two statements about WSOC. Then two sentences about the results. And then, another two sentences. They are in one paragraph, but I cannot find the chain of ideas. What did you want to tell us? These sentences are almost incoherent. Please, rethink it!

Re: Delete the discussion about water-soluble organic carbon from the article. This part originally discussed whether there is an internal connection between changes in water-soluble organic carbon and soil microorganisms, but it is difficult to find the entry point in the research content of this paper, and the discussion value is not high.

Line 297-302: Perfect starting and then an understandable argument. I liked it! I think something similar for the previous and following paragraphs.

Line 303 Difference of what?

Re: Here we rephrased as “The readily oxidation organic carbon content no significant difference between the transformed C. lanceolata and P. massoniana plantations and their reference plantations”.

Line 305f: Why?

Line 305-309: Can you refer to some studies from where these ideas may come? OR are these just your intuitions?

Re: We reinterpreted it and added references[27].

 Line 310-312: take this sentence into the Introduction or take it after your results…

Re: There was a description in the introduction, so we deleted the sentence.

 Line 314: Increased compared to what? In time? In space?

Re: In space. All of comparations in this study are “in space”.

Line 316: Did you measure these variables, the litterfall and the decomposition? So, from where do you know it?

Re: Part of our experiment was the decomposition dynamics of litters, and the conclusions were drawn based on reference [28]. However, the data of litter quantity are not reflected in this paper.

Line 314-318: Do you think you used an inadequate method to measure the particulate organic carbon?

Re: Our measurement method of organic carbon refers to the industry standard, and the data is reliable. See reference [21].

 Line 320-321. What do you think about the carbon pool and the soil fertility of the plantations? You mentioned, that the POC is a good indicator for these. What is the conclusion?

Re: Corrected as suggested. Here we rephrased as “CNT had significantly increased the particulate organic carbon content of the 10-30cm soil layer. The results showed that the close to-natural transformation was not only beneficial to the accumulation of soil organic carbon, but also could effectively improve soil quality.”

Line: 323-325. Into Introduction or into the arguing.

Line 330. Decrease? You didn’t know the starting values, did you? Then you know only differences between treated and untreated plantations.

Line: 328-333: I don’t understand this sentence. What do you mean that “basically consistent with the response of ROC”? ROC did not differ between PCK and PCN, so there was no “response”. The mentioned nutrient “decreased after” the treatment, but there was no difference between the plantations.

Line 336: Causing? Are you sure that soil carbon content changes because of the changes of soil physical and chemical characters? You found correlations, that’s all. It doesn’t mean causality.

Re: We have revised this part of the discussion.

 Line 349-351: This is the same result as in lines 333f… You should summarize the results and explanations more effectively… The Discussion part is too long. You should point out the most important results and avoid redundancy like this.

Re: We have simplified this sentence

Line 358: You previously discussed the different variables and their relations, and now comes the plantations… What is now important?

Re: Discussed above is two kinds of plantation (Cuninghamia lLanceolata and Pinus massoniana plantations) soil nutrient and organic carbon, the relationship between these variables is caused by the two stand transformation processing, but two stand on the same transform processing has a different response, and thus presumably transformation between the two kinds of tree species to the effect of nutrient and organic carbon also vary accordingly, there is only one possible explanation.

Line 367-371. Introduction or explanation…

Re: Here we delete reference 36 and keep reference 37. Reference 37 is the foreshadowing of the following text.

Line 373-374: Increased again…

Re: Comparations here is also compared “in space”.

Line 396: Please, leave this: “it is found in the study”: if you refer to a study/article/work, it means the same. It is enough to write down the main result and then write the reference number [42]. That’s it.

Re: Here we rephrased as “It is found in the study of Sinsabaugh [42] that higher nitrogen availability would promote the degradation of unstable organic carbon”.

Line 402 Why is it a problem that the samples were taken in the growing season?

 Re: As mentioned above, seasonal changes and microbial community changes can affect soil carbon storage and enzyme activities. In this paper, we only sampled in August of the growing season, and did not compare seasonal changes and microbial communities. Therefore, this may be one of the reasons for no difference between near-natural and control stands, rather than sampling problems during the growing season. Here we rephrased as “Due to sampling only in the growing season, this study lacks relevant data to study seasonal changes and microbial community structure.”

Conclusion

A conclusion is a short and tight summary of the results and the consequences. Not a list of results. Please, reconsider this paragraph and reconsider the concept of the manuscript.

 Re: Here we rephrased as”Close to nature transformation can improve the soil organic carbon and enzyme activity in coniferous plantation, and the change components mainly are actively carbon, which was closely related to soil enzyme activities and soil chemical properties, among them, soil pH, total nitrogen and catalase were the main factors affecting organic car-bon components. The results showed that close to nature transformation will promote soil organic carbon accumulation by changing the composition of tree species, but had a negative effect on soil organic carbon stability to a certain extent. Therefore, the effect of tree species configuration on soil carbon stability components should be considered in the practice of forest management.” See 5.Conclusion.

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

The manuscript has been sufficiently revised.

Author Response

Dear reviewer,

Thank you very much for your hard work and valuable suggestions in our manuscript review. We have optimized our manuscript again according to the modification suggestions of reviewers and editors. If you have any new suggestions, please feedback to us again, thank you very much!

With best regards,

Weiwei Shu

On behalf co-authors

Reviewer 2 Report

General

I could see that the Authors made effort to modify their manuscript about my suggestions and questions and the manuscript has developed.

However I missed some explanations and responses of my suggestions and questions. How come that the Authors let many of my comments and questions unanswered? I missed their reaction about my suggestion to reconsider the topic of the manuscript. I can see that the Authors made corrections, however, I expected some direct answer.

I was sorry about that the Author did not take the trouble over writing the numbers of the corrected lines in the manuscript. I know, it takes a lot of time to find the referring lines, I made it for them, but they did not do it for me. It is helpful for the reviewer and it is also about politeness. I suggest to do it in the future.

I have some further comments, corrections and suggestions which should be considered.

Detailed

Abstract

Now it is better than the previous version.

line 24: of effects… I suggest to read again the manuscript, there are some more misspellings.

line 29-30: Reconsider this sentence.

line 35: CNT protease?!

Introduction

line 88: If a reviewer asks something („has changed”), it means that this part is not clear in the manuscript, therefore, the Authors should answer it also in the manuscript.

line 143: Increase? Compared to what?

Material and methods

Lines 188-189: So You had double samples in soil level 0-10cm? Or the first part was 10-50 cm?

Reference 24: I am really sorry that you have only one book for these methods as this book is in Chinese so I cannot decide whether these methods are good for this analyses.

Line 217: package... And I still miss the R citation.

Line 219: I don’t find the justification about one-way ANOVA satisfactory. It is not a justification that these variables are not the focal variables. In addition, You didn’t answer my question about model diagnostics as well.

Statistical analyses

RDA is not correctly described. What happened with the nine sample repetitions within a “sampling point”? Why did you delete the sentence of lines 300-302.

Results

line 225: Physical?

Line 232 I thought that You understood my problem with the word “increase” according to the corrections in section 3.2. But now I see that you did not.

Line 236: dierence?

line 300-301. I didn’t say to delete this sentence, I suggested to transfer into Methods section. It is important information.

Caption of Figure 1. What does ABC and abc mean?

Figure 3. I can see that you corrected the figure. However, not all the abbreviations are in the caption. ACP? URE? etc. A figure must be understandable in itself. Another question. I understand that the four signs might mean the 4-4 stands within treatments. Now I don’t understand, what happened with those 9 samples within a “sampling point”. Did you calculate average and these average values were in the model? The RDA description was still superficial. In addition, in your new figure, we can see new results (similarity between treated plantations and dissimilarities between the control plots). I suggest to mention it in the text.

 

Discussion

line 372: the verb is absent from in this sentence.

line 382: need to be further study?

lines 387-388: CNT increased POCC of the 10-30 cm soil layer. Compared to what if you did not find significant differences?

My previous question (previous line 314), and you answered it to me, but it is not enough, if a reviewer asks something it means that it not understandable in the manuscript so you should correct it in the main text…

line 397: where do you know it? Did you measure agglomeration capacity and root exudates?

line 414: hydrolysable n???

line 417: physical properties?

line 439-441: citation? You did not measure microbial variables. Or is it the results of [34]?

lines 446-450: however, this sentence did not justify the difference between the two plantation types.

lines 457-458. Increased again. Did you measure these values previously? You wrote that these differences are in space. How could a variable increase in space? It was higher in transformed and lower in control plantation, but it did not increase.

Conclusion

It is a much better conclusion. I like it.

Author Response

Dear editor

 

Thanks very much for the efforts for the review of our manuscript. Please find below our responses to the comments of the reviewers and explanations how we addressed the critical points. We are grateful for the very constructive suggestions, which certainly helped to improve our manuscript. We hope this revised version is acceptable for publication and please let us know if there is something further needs to be done.

Hereby you will also find our attached response letter in italics as WORD file to the respective comments as supplemental material.

Thank you very much for your patience.

 

With best regards,

Weiwei Shu

On behalf co-authors

 

 

 

Comments and Suggestions for Authors

General

I could see that the Authors made effort to modify their manuscript about my suggestions and questions and the manuscript has developed.

However I missed some explanations and responses of my suggestions and questions. How come that the Authors let many of my comments and questions unanswered? I missed their reaction about my suggestion to reconsider the topic of the manuscript. I can see that the Authors made corrections, however, I expected some direct answer.

I was sorry about that the Author did not take the trouble over writing the numbers of the corrected lines in the manuscript. I know, it takes a lot of time to find the referring lines, I made it for them, but they did not do it for me. It is helpful for the reviewer and it is also about politeness. I suggest to do it in the future.

I have some further comments, corrections and suggestions which should be considered.

Detailed

Abstract

Now it is better than the previous version.

line 24: of effects… I suggest to read again the manuscript, there are some more misspellings.

Re: Corrected as suggested. See line 23-25.

line 29-30: Reconsider this sentence.

 Re: Corrected as suggested. We rephrase this sentence as “Compared with control stands (CCK and PCK), CNT enhanced soil organic carbon”. See line29-30

line 35: CNT protease?!

Re: Corrected as suggested. We rephrase this sentence “After the CNT, the protease, urease and acid phosphatase activities in the C. lanceolata plantations were higher than control stands, while protease and catalase in P. massoniana plantations were higher than control”. See line 36-38.

Introduction

line 88: If a reviewer asks something („has changed”), it means that this part is not clear in the manuscript, therefore, the Authors should answer it also in the manuscript.

Re: Corrected as suggested. See line 89.

line 143: Increase? Compared to what?

Re: Corrected as suggested. We rephrase this sentence “Compared with the control forests, CNT can promote soil organic carbon and stability”. See line 143-144.

Material and methods

Lines 188-189: So You had double samples in soil level 0-10cm? Or the first part was 10-50 cm?

Re: Yes, 0-10cm of soil we mixed and divided into two parts. Air-dried soil was used for the determination of soil organic carbon components and chemical properties. Refrigerated soil was used for determination of enzyme activity, ammonium and nitrate nitrogen. This section is described in more detail. See 192-193.

Reference 24: I am really sorry that you have only one book for these methods as this book is in Chinese so I cannot decide whether these methods are good for this analyses.

Re: We reconfirmed our assay method with the laboratory, corrected the catalase assay method, and added references related to the assay method to all enzymes. References 24, 25, 26 and 27 have been added here.

Line 217: package... And I still miss the R citation.

Re: Reference has been added. See reference [28].

Line 219: I don’t find the justification about one-way ANOVA satisfactory. It is not a justification that these variables are not the focal variables. In addition, You didn’t answer my question about model diagnostics as well.

Re: We have completed normal distribution and homogeneity tests for all the data in the whole paper, and have made relevant descriptions in the manuscript. The RDA model was optimized (some variables with little correlation and collinearity were deleted, and only important factors were retained), and the test results were supplemented in the relevant positions of the manuscript. See 2.4 Statistical analyses.

Statistical analyses

RDA is not correctly described. What happened with the nine sample repetitions within a “sampling point”? Why did you delete the sentence of lines 300-302.

Re: I am really sorry, it is our previous wrong explanation that has brought misunderstanding to you. In this study, we selected 16 sample plots in 4 stands. Nine sampling points were randomly selected from each plot. The fresh and partially decomposed litters on the surface were removed, and then soil samples were collected at three depth, 0–10, 10–30, and 30–50 cm. A total of 27 soil cores were collected using an 8.7-cm-diameter stainlesssteel core from each plot and bulked to one composite sample per depth. We have modified part 2.3. See 185-188. In addition, we replaced lines 300-302 into the caption in Figure 3.

Results

line 225: Physical?

Re: Our research does not involve Physical properties, so "Physical" in the title has been deleted.

Line 232 I thought that You understood my problem with the word “increase” according to the corrections in section 3.2. But now I see that you did not.

Re: Corrected as suggested.

Line 236: dierence?

Re: I'm sorry, this is our spelling error, which has been modified to "difference". See line 242-244 . We have proofread the contents of the manuscript repeatedly, and we hope that this problem will not trouble you again!

line 300-301. I didn’t say to delete this sentence, I suggested to transfer into Methods section. It is important information.

Re: Thank you very much for your suggestion. We read the whole text and finally added this sentence to the description in Figure 3. See line 334-339.

Caption of Figure 1. What does ABC and abc mean?

Re: Added as suggested. See line 275-277.

Figure 3. I can see that you corrected the figure. However, not all the abbreviations are in the caption. ACP? URE? etc. A figure must be understandable in itself. Another question. I understand that the four signs might mean the 4-4 stands within treatments. Now I don’t understand, what happened with those 9 samples within a “sampling point”. Did you calculate average and these average values were in the model? The RDA description was still superficial. In addition, in your new figure, we can see new results (similarity between treated plantations and dissimilarities between the control plots). I suggest to mention it in the text.

 Re: A description of all abbreviations was added to the title as suggested. See line 334-339. The problem of “sampling points” has been explained in the previous paragraph. In addition, we optimized the RDA model (deleting some non-correlated and collinear variables), and supplemented the test results at the relevant locations of the manuscript. See line 311-320.

Discussion

line 372: the verb is absent from in this sentence.

Re: Corrected as suggested. See line 398-400.

line 382: need to be further study?

Re: We rephrase this sentence “However, the more detailed reasons need to be further analyzed”. See line 411-412.

lines 387-388: CNT increased POCC of the 10-30 cm soil layer. Compared to what if you did not find significant differences?

My previous question (previous line 314), and you answered it to me, but it is not enough, if a reviewer asks something it means that it not understandable in the manuscript so you should correct it in the main text… 

Re: Corrected as suggested. We rephrase this sentence“The content of particulate organic carbon in the close to nature transformation plantation at 10-30 cm soil layer was significantly higher than that in the control plantation.”See line 415-417.

line 397: where do you know it? Did you measure agglomeration capacity and root exudates?

Re: This is what we found in the literature. We added the references.

 line 414: hydrolysable n???

Re: Corrected as suggested. See line 445-448.

line 417: physical properties?

Re: Corrected as suggested. Deleted “physical properties”. The whole paper is also examined

line 439-441: citation? You did not measure microbial variables. Or is it the results of [34]?

Re: This is the result of reference 34.

lines 446-450: however, this sentence did not justify the difference between the two plantation types.

Re: Corrected as suggested. See line 477-481.

lines 457-458. Increased again. Did you measure these values previously? You wrote that these differences are in space. How could a variable increase in space? It was higher in transformed and lower in control plantation, but it did not increase.

Re: We have revised the sentences in the manuscript that touch on the relevant issues.

Conclusion

It is a much better conclusion. I like it.

 

Author Response File: Author Response.docx