Influence of Vegetation Types on the C, N, and P Stoichiometric Characteristics of Litter and Soil and Soil Enzyme Activity in Karst Ecosystems

Round 1

Reviewer 1 Report

Manuscript ID: forests-2256064

Type: Article

Title: Influence of vegetation types on litter and soil C, N, P stoichiometric characteristics and soil enzyme activity in karst ecosystem

Authors: Min Zhao , Quanhou Dai * , Liekun Zhu , Pengwei Ding , Zeyin Hu , Hong Zhou

 

Dear Assistant Editor of Forests

 

The manuscript entitled " Influence of vegetation types on litter and soil C, N, P stoichiometric characteristics and soil enzyme activity in karst ecosystem " has studied the carbon, nitrogen and phosphorus contents of litter and soil, the activities of alkaline phosphatase, sucrase, urease and catalase of soil were measured in grassland, shrubland, arbor-shrub mixed forest and arbor forest in Shiban Town, Huaxi District, Guiyang City, Guizhou Province. Statistical analyses have done. Results showed the the litter N content and soil C and N contents were the highest in arbor forest among all vegetation types. The C:P and N:P ratios in litter and soil in arbor forest and arbor-shrub mixed forest were significantly or slightly higher than those in the other two vegetation types. The activity of four soil enzymes was : arbor forest > arbor-shrub compound forest > shrubland > grassland.

The subject of the research work is original and has been able to provide a lot of new information in the field of soil and litter ecological stoichiometry and soil enzyme activities under different vegetation types in karst area. The authors were able to answer the research questions due to the review of suitable sources, the study method of the region and the sufficient number of samples, and there is no need for additional items in the method and also other controls. The authors were able to match the research conclusions well with the evidence and arguments presented and address the main question raised. References were well presented and good previous researches were listed, however, some related references proposed that should be mentioned in the manuscript. Tables and figures are well organized and logically consistent with the content of the text.

The study design is robust and the topic fits well to the scope of the journal. The manuscript is generally clearly designed, written and illustrated. The discussion of the manuscript also well written. I recommend this paper for publishing after addressing some minor comments presented on the PDF file.

 

Best regards

 

Comments for author File: Comments.pdf

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

The paper examines the responses of litter and soil carbon, nitrogen, phosphorus, and soil enzyme activities to four plant types in a Karst ecosystem. This study is interesting but there are several issues related to the manuscript presentation and data presentation and interpretation. Although this study is appropriate for publication in the journal, I have a few concerns with aspects of the paper. In addition, the writing has a lot of errors and the manuscript needs major improvement by a native speaker. There are many long sentences that make me confused and so many “of” in this manuscript.

- Abstract - this needs to be revised or rewritten. The authors must give more convincing background information about the necessity of their study. You said that “The interaction between soil……in karst area remain poorly understood”. Only “poorly understood” is not necessary. Meanwhile, it is easy to search some articles about these topics conducted in Karst areas (such as: DOI: 10.13227/j.hjkx.201812221, DOI：10.13287/j.1001-9332.2014.0068, and DOI: 10.17520/biods.2017148), thus, it seems that this topic is not poor.

- Introduction - the introduction is general. The authors should give more detailed background information about this topic. For instance, in the second paragraph, the author said the response of nutrient stoichiometry to changes in vegetation types is quite complex and mainly depends on the initial nutritional status, climatic characteristics, and altitude. However, there is not any detailed information describing how vegetation types affecting nutrient stoichiometry and the specific roles of nutritional status, climatic characteristics, and altitude during these processes. The background on mechanisms presented as a motivation for the study is thus not sufficient. Meanwhile, there should be hypothesizes at the end of the Introduction section.

- Materials and methods - the material and methods section needs some more information and explanations (see my specific comments).

- Data presentation and interpretation - The authors have tried to correlate the different measured variables but are not doing so mechanistically. There needs to be more effort to provide a mechanistic explanation to the observed trends rather than just focusing on correlation. There is not enough explanation for why these trends exist and because of this. This makes the overall discussion section of the manuscript very weak.

- Discussion - This part needs major revision.

Specific comments:

Line 14: “The” should be “the”.

Line 14: the carbon(C), nitrogen(N) and phosphorus(P) contents should be the carbon(C), nitrogen(N), and phosphorus(P) contents. Please note the use of "comma" before the and.

Line 23: please give an accurate description here than “significantly or slightly”.

Line 24: same as line 23: significantly or marginally.

Line 26: what´s the meaning of the sentence “P element showed a delayed effect in litter and soil”?

Line 27-28: this sentence makes me confused. You said that The activity of four soil enzymes was: arbor forest……> grassland. The activity of four soil enzymes was forest types? The sentence should be The activity of four soil enzymes in four vegetation types ranked: arbor forest……> grassland.

Line 30: what´s the meaning of this sentence? what´s the “plants of each vegetation types”? How does the way of N element coupled with the plant? What does nitrogen regulate plants?

Line 39: nitrogen(N) and phosphorus(P) contents should be the carbon(C), nitrogen(N), and phosphorus(P) contents. Please note the use of "comma" before the and. Please revise it in the whole paper.

Line 40: the comma behind “growth” should be a period.

Line 49: please replace the first “and” with a comma.

Line 58: affect should be affected

Line 64: enzymes should be enzyme

Line 70-73: this sentence needs to be rewritten.

Line 77-78: research should be researches. Focuses should be focus.

Line 86: explore should be exploring

Line 89: reveal should be revealing

Line 96-98: please rewrite this sentence to make it more logical. Meanwhile, please provide detailed information of soil classification.

Line 107: why is the “may be” here?

Line 108-117: how to establish the sample plot in the sample point? Is the sample point equal to vegetation types? why are the total samples 240? Should not it be 6 (sample points) ×5 (one-square-meter quadrats) ×4 (vegetation types)=120?

Line 137-141: please rewrite this paragraph. Please provide detailed information of these analysis softwares. What is the mean of “preliminary statistical analysis”? Do you test the differences in soil and litter stoichiometry and soil enzyme activity across the vegetation types using ANOVA? Please provide detailed information about dimension reduction analysis.

Line 149 and 151: what are the “TN” and “TP”?

Line 153: please add which in before the abor.

Line 157-159: what is the meaning of this sentence-“the distribution law of litter and soil nutrients was not obvious with the change of vegetation type”? You described the significant difference in the 3.1.1 section.

Line 178-180: why do you conclude this? Please give specific information.

Line 271-273: please provide the reference.

Line 279-281: the spatial heterogeneity of litter C, N, and P in karst areas is a result or phenomenon. Here, what you should do is explain why it is different among different karst areas.

Line 284-287: please provide the reference. Meanwhile, you said that the sampling time is spring, thus there was higher litter N and P content in our study area than the global average. So, does our result really reflect the litter characteristics in our study area?

Line 292-294: please provide the reference.

Line 294-295: please provide the reference.

Line 334-335: please provide the reference.

Line 361-363: our result can conclude this?

 

 

 

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

The manuscript presents the results of small local experiment and very simple combination of factors. Although I know plenty of similar experiments and papers with much broader combinations of factors, it may be accepted as a kind of case study. In this sense the manuscript is original. 

However, the analysis of results and the evaluation of conclusions suffer from insufficient background information. Maybe these factors are not important i this case and don't influence the final conclusions, but the reader cannot judge it until these data are not presented.

Authors should provide at least:

- soil name/classification using internationally accepted standards. "Yellow soil" means nothing for researchers in Europe or Africa. If you don't have your own recognition, you may check the dominant soils (by FAO-WRB classification) in the area of your study in the SOILGRIDS platform (check: soil classes):

https://soilgrids.org/

- soil texture - at least dominant texture classes for particular land use types (follow an international standard by USDA)

- soil pH!!!

All above mentioned factors are important for biochemical processes and and create the frame for interpretation of similar results in various climate, vegetation and soil zones.

Moreover, I suggest to avoid political statements in the scientific journal. Therefore, I suggest modifying the map in fig. 1 to omit political questions in a marine area that have nothing to your study area and topic...  

 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

Line26-28：please give the significant level when you compare something.

Line58: “Their” should be “their”.

 

Line 167-169: please add detailed information of the software, such as Canoco 5.0 (Centre for Biome- try, Wageningen, the Netherlands). You should give this information about SPSS 21.0 and Origin 2021.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf