Variations and Mutual Relations of Vegetation–Soil–Microbes of Alpine Meadow in the Qinghai-Tibet Plateau under Degradation and Cultivation
Round 1
Reviewer 1 Report
The authors presented an interesting paper, made at a high scientific level.
The work can be published with minor changes:
1) The terms "land" should be replaced with "soil" where possible.
2) The information in the paragraph (lines 80-93) describing sampling sites would be better transferred to Materials and methods section.
3) In the legend of figures and tables, it is desirable to explain the abbreviations, because they are not generally accepted.
4) In section 2.3. what units are we talking about? mm is millimeter
Author Response
Point 1: The terms "land" should be replaced with "soil" where possible.
Response 1: Thanks for your suggestion. We have replaced the terms ‘land’ with ‘soil’ in some sentenes and marked in red font. And the terms ‘land’ were deleted in some sentences.
Point 2: The information in the paragraph (lines 80-93) describing sampling sites would be better transferred to Materials and methods section.
Response 2: Thanks for your suggestion. We have transferred the sentences describing sampling sites to Materials and methods section. And the transferred sentences are marked in red font.
Point 3: In the legend of figures and tables, it is desirable to explain the abbreviations, because they are not generally accepted.
Response 3: Thanks for your suggestion. We have explained the abbreviations in the legend of figures and tables.
Point 4: In section 2.3. what units are we talking about? mm is millimeter.
Response 4: Thanks for your query. the unit ‘mm’ is the abbreviations of ‘millimeter’, which is general usage in the articles. Therefore, we decides to keep it as it is.
Reviewer 2 Report
- This study mainly explores variations and mutual relations of vegetation-soil-microbes of alpine meadow in the Qinghai-Tibet Plateau under degradation and cultivation. However only statistical analysis was performed on general sampling, and there was no appropriate experimental design for research gaps. The discussion of interrelationships and cause and effect is not convincing.
- The description in the abstract "Combined with vegetation and soil variables, we speculated that the unstable AAG was obviously improving from degraded meadow but not significantly, and there was still a large gap between IAM and AAG.". This is not scientific writing; it violates the statement of the level of statistical significance.
- Correlation analysis, redundancy analysis, and partial mantel test analysis should be discussed in relation to the experimental purpose of the research gap, indicating whether it conforms to the hypothesis of the original experimental design. A passive or selective discussion of outcomes alone cannot address causal relationships between parameters.
- The variation of vegetation-soil-microbes in alpine meadows and their relationship is a systematic study, and the relationship of vegetation-soil-microbes cannot be discussed separately. If causality is involved, independent and dependent variables should be clearly defined.
- The authors adopted many experimental and statistical analysis methods, but did not carry out field trial design and statistical analysis to address the gaps in previous studies. The results and discussions throughout the article are a bit messy. It is recommended that the author conduct a focused discussion on the problems that need to be solved.
- This study should have its own experimental design. The slope variation of each treatment plot and sampling interval in Table S1 is too large, especially the slope of the AAG plot is 0, and the experimental design is greatly affected by the terrain.
- The writing of Figure or Fig in the full text should be consistent.
- In an ecosystem, the environment and organisms influence each other, and the result cannot be the cause. The description of " Together these results provide important insights that soil pH, WC, TN, TOC, C/N, BD, vegetation coverage, and aboveground biomass are the key factors affecting the microbial alpha diversity and gene copy number under community level. " is inappropriate.
Author Response
Point 1: This study mainly explores variations and mutual relations of vegetation-soil-microbes of alpine meadow in the Qinghai-Tibet Plateau under degradation and cultivation. However only statistical analysis was performed on general sampling, and there was no appropriate experimental design for research gaps. The discussion of interrelationships and cause and effect is not convincing.
Response 1: Thanks for your comment. These comments deepen the reflection about the out article. The purpose of this article is to analyze the characteristics of vegetation-soil-soil bacterial changes in the context of degradation and recultivation, especially the degraded alpine meadow are always transformed to the artificial grassland to improve grass productivity and relieve the grazing pressure on the natural meadow. And it is significant to evaluate whether artificial cultivation of degraded alpine meadow can effectively improve degraded environments. Based on this background and purpose, degradation and reconstruction are analyzed as a completed successional series to understand the changes in biotic and abiotic factors and identify the key environmental factors to regulate the bacterial community under different taxonomic levels. Selection of typical county units can reduce the influence of climatic factors, ie. temperature and precipitation. Typical vegetation types including intact alpine meadow (IAM), moderately degraded meadow (MDAM), extreme degraded meadow (black soil beach (BSB)), and artificial alpine grassland (AAG) were adopted. The classification and determination of degraded meadows refer to You et al. (2014). that is, the intact alpine meadow (IAM) was adopted with >90% vegetation coverage, averages 5 cm tall, and >80% edible forage coverage; Approved MADM was characteristics of 50-70% vegetation coverage and 20-50% edible forage coverage; the vegetation and edible forage coverage of the BSB was below 50% and 5%, respectively. The artifical grassland cultivated by Elymus nutans always cover in flat land are also adopted. 6-11 plots (20×50 m) were applied to each style with different degradation and cultivation, and three random quadrats (50 cm×50 cm) (replicates) were arranged within each plot. In each plot, vegetation investigation and soil collection (please refer to the manuscript for details of the sampling process) follows the relevant protocols. Topographic factors, such as slope in each plot, is inevitable in the process of sampling, which is overlooked in the previous studies. Therefore, the slope and altitude are recorded in Table S1 and evaluated the relationships with soil bacteria. Although the the slope of sampling plots span large, it correted with soil bacteria under non-significant level (Table 3). Concerning the interrelationships and cause and effect, there is a little imprecise in presentation in our article. We calibrate the presentation to avoid being unconvincing througout the manuscript. All modification is presented in red font.
You, Q.G., Xue, X., Peng, F., Xu, M.H., Duan, H.C., Dong, S.Y. 2014. Comparison of ecosystem characteristics between degraded and intact alpine meadow in the Qinghai-Tibetan Plateau, China. Ecol. Eng. 71, 133–143.
Point 2: The description in the abstract "Combined with vegetation and soil variables, we speculated that the unstable AAG was obviously improving from degraded meadow but not significantly, and there was still a large gap between IAM and AAG.". This is not scientific writing; it violates the statement of the level of statistical significance.
Response 2: Thanks for your comment. Please forgive us for imprecise presentation. We have replaced the previous sentence as ‘……, it was speculated that the unstable AAG was not significantly improving from degraded meadow, and also lagged a large gap to IAM ’. Also the similar presentation is modified in the manuscript. The modification in presented in red font.
Point 3: Correlation analysis, redundancy analysis, and partial mantel test analysis should be discussed in relation to the experimental purpose of the research gap, indicating whether it conforms to the hypothesis of the original experimental design. A passive or selective discussion of outcomes alone cannot address causal relationships between parameters.
Response 3: Thanks for your comment. Correlation analysis, redundancy analysis, and partial mantel test analysis are applied to evulate the relationships among the biotic and abiotic factors under degradation and cultivation. And redundancey analysis also applied to compare the importance of different environmental factors to regulate the bacterial community under different taxonomic levels. The results from correlation and partial mantel test in former submitted manuscript can not address causal relationships between biotic and abiotic factors. Therefore, we carefully revised the related expression throughout the manuscript to conforms to the hypothesis of the original experimental design. All anaysis conforms to the purpose of this manscript. All modifications in presented in red font.
Point 4: The variation of vegetation-soil-microbes in alpine meadows and their relationship is a systematic study, and the relationship of vegetation-soil-microbes cannot be discussed separately. If causality is involved, independent and dependent variables should be clearly defined.
Response 4: Thanks for your comment. The mutual relationships between two parameters along the degradation and cultivation are considered in this study. Further analysis foucus on the effect of vegetation and soil variables on soil bacteria with the help of RDA. Please forgive us for abiguous expression. We have rejusted the structure of the manuscript and the relationship of vegetation-soil-microbes are presented and dicussion in together. Also independent and dependent variables are clearly defined based on the RDA result. All modifications in presented in red font.
Point 5: The authors adopted many experimental and statistical analysis methods, but did not carry out field trial design and statistical analysis to address the gaps in previous studies. The results and discussions throughout the article are a bit messy. It is recommended that the author conduct a focused discussion on the problems that need to be solved.
Response 5: Thanks for your comment. Degradation and cultivation are selected as a completed successional series to understand the changes in biotic and abiotic factors and explore their relationships under diffent taxonomic levels in this study.The typical county in the Qinghai-Tibet Pleatue and typical degradation and cultivation styles are selected to achieve this purpose. As a significant improvement for the alpine meadow degradation, the artificial cultivation was always neglected in the previous studies, which is not conducive to fully and accurately understand the change rules of soil factors along the alpine meadow degradation and cultivation. Furthermore, the relationships between soil microbe and factors under different taxonomic levels were always neglected in previous studies. These expression also presented in the Introducation part. Therefore, the varations of biotic and abiotic, and their relationships under different taxonomic levels are the focus of discussion. And we have rejusted the structure of manuscript to keep the Result and Discussion in consistent. All modifications in presented in red font.
Point 6: This study should have its own experimental design. The slope variation of each treatment plot and sampling interval in Table S1 is too large, especially the slope of the AAG plot is 0, and the experimental design is greatly affected by the terrain.
Response 6: Thanks for your comment. Terrain factors, such as slope, is inevitable in the process of sampling, which is overlooked in the previous studies. Although the the slope of sampling plots span large, it was proven that it correted with soil bacteria under non-significant level (Table 3).
Point 7: The writing of Figure or Fig in the full text should be consistent..
Response 7: Thanks for your comment. We have kept the writing in consistent throughout the manuscript.
Point 8: In an ecosystem, the environment and organisms influence each other, and the result cannot be the cause. The description of " Together these results provide important insights that soil pH, WC, TN, TOC, C/N, BD, vegetation coverage, and aboveground biomass are the key factors affecting the microbial alpha diversity and gene copy number under community level. " is inappropriate..
Response 8: Thanks for your comment. As you suggested, the results of the correlation analysis cannot be the cause of the causality. We have cheacked the manuscript to delete the related expression. The description of ‘Together these results provide important insights that soil pH, WC, TN, TOC, C/N, BD, vegetation coverage, and aboveground biomass are the key factors affecting the microbial alpha diversity and gene copy number under community level’ are replaced by ‘Together these results provide important insights that soil pH, WC, TN, TOC, C/N, BD, vegetation coverage, and aboveground biomass are the important factors closely associating with microbial diversity and biomass under community level.’
Reviewer 3 Report
The manuscript is well written and the analysis is soilidate. I have few comments: 1. The figure of the study area should appear in the content but not the supplementary file. 2. Some sampling photos should be added to show the measures in this study. 3. The figure quality should be improved.Author Response
Point 1: The figure of the study area should appear in the content but not the supplementary file.
Response 1: Thanks for your suggestion. We have put the figure of the study area in the content.
Point 2: Some sampling photos should be added to show the measures in this study.
Response 2: Thanks for your suggestion. We have provided photos about the four types of alpine meadows in the manuscript.
Point 3: The figure quality should be improved.
Response 3: Thanks for your suggestion. We have improved the resolution of the figure.
Round 2
Reviewer 2 Report
Dear Authors,
Thank you for considering all suggestions.
I think your work can be published.
Good luck!
