Contribution of Climatic Factors and Human Activities to Vegetation Changes in Arid Grassland

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Dear Authors,

I reviewed your manuscript. The topic is interesting and you made good efforts concerning topic discussion, extensive analysis with obvious conclusion. For the manuscript to be ready for publication, I would like to ask you to address the following points:

1 - Reference should be in number throughout the manuscript as required by the journal.

2 - In section 3.4, it is mentioned that the H-Index is used to characterize the future vegetation changes, you need to mention what is meant by the future changes and with respect to what?

3 - In line 382, it is mentioned that superimposing the H-Index, NDVI development trend, and significance during 382 2000–2020, the above results were divided into seven categories, can you demonstrate more what is meant by this sentence?

4 - Kindly remove all lines in the reference list.

Best Regards

 

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The manuscript “Contribution of climatic factors and human activities to vegetation changes in arid grassland” is well structured, the objectives are met according to the results, great data processing and analysis is demonstrated, the methodology is interesting and timely, so it would be very interesting for the scientific community and to decision makers. However, the deficiency lies in the analysis of human influence on vegetation changes, which may be insufficient to reach conclusions. Specific comments below:

- Verify the correct form of citation and references.
- Cite line 97.
- In Figure 1 you can be invert the DEM color scale.
- Explicitly explain the statistical analysis with human factor data.
- Why were only population densitie considered as human factors in the analysis?
- In what software or program were the statistical analyzes performed?
- In the introduction some variables related to the climatic influence on the NDVI are mentioned but examples of variables consider as human factors are not mentioned.
- Improve the conclusion with the scope of the study worldwide.
- If other variables of human influence are not used, can it be stated that the main determinant of changes in vegetation was climate?

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

The paper is interesting and uses a very important and useful set of data for hydrological cycle processes related to vegetation change.

The submitted paper should be published, after the authors have answered some questions.

The specific comments for the authors are related to the three objectives of the work:

1. To analyze the dynamic changes and future evolution of the vegetation cover trend in the grassland region. This objective is not completed. The authors do not show the results of a statistic or any statistical test to determine scientifically and categorically the trend of the time series. The authors mention it, but how the trend tests were performed is not explicitly shown. A linear plot of the time series and a correlation coefficient is not enough.

2. To study the characteristics of temporal and spatial variation of climatic factors in the region and their correlation with NDVI. This objective is not completed; spatial results are shown but not temporal ones. Usually cartography shows the spatial results. And the use of tables relates the temporal results (it is a recommendation-suggestion).

For example, the results shown in section 3.2.1 should be presented in tabular form. This would allow a clearer comparison of the temporal variation of temperature and precipitation.

3. Quantify all-year and growing season weather conditions and human activity to NDVI. This objective is satisfied, showing evidence of how human activities contribute to changes in vegetation through space and time.

Methodology. The statistical methodology is basic but correct. The application of the Hurst index is interesting and well applied.

The paper should be accepted, once the authors answer the above questions.

Author Response

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Author Response File: Author Response.pdf

Reviewer 4 Report

Comments and Suggestions for Authors

1. The study examines the influence of specific climatic parameters and the human intervention factor to the Yinshanbeilu grassland region vegetation changes based on correlations to Normalized Difference Vegetation Index (NDVI) in the past 21 years. The results offer useful information and provide guidance towards the protection and restoration of the Yinshanbeilu grassland region. In this context the paper is evaluated as deserving acceptance for publication after considering a few followed minor recommendations. 

2. In Abstract: Line 11, a more complete description of the Yinshanbeilu area should be given (i.e. in north-northeastern China). 

3. Abstract: Lines 12-13 needs some correction in “We focused examined”. 

4. Abstract: Line 13, the words “the years” should be added before 2000. 

5. In Abstract: Line 14, the full words of acronym NDVI should be giving since it is first appeared in the text. 

6. In 1. Introduction: Lines 58-61, the expression “This region is semi-arid……etc.” has some confusing meaning and needs a better syntax or dividing in two separate expressions. 

7. In 2. Materials and Methods, 2.2. Data Source and preprocessing: Some additional information should be provided i.e. it could be in a form of a Table concerning the various data sets or the total data points or total records used in the analysis followed. 

8. In 3. Results 3.1. Temporal and spatial changes of vegetation in the Yinshanbeilu grassland region, 3.1.2. Seasonal changes of NDVI: In Figure 4 legend, line 225, the indices k and R² should be also mentioned. 

9. In 3. Results, 3.1. Temporal and spatial changes of vegetation in the Yinshanbeilu grassland region, 3.1.2. Seasonal changes of NDVI: In Table 2 under the head of column “Growing Season” should be also added in parentheses the seasons or approximate time included in the growing season. 

10. In 3. Results, 3.3. Impact of climate change and human factors on vegetation changes, 3.3.1. Contribution of climate change to vegetation changes: In line 337 some verb is probably missing, so that give a complete meaning. 

11. In 4. Discussion, 4.2. Impact of climate change factors on vegetation changes, 4.2.1. Precipitation affects vegetation changes: In line 429, some brief comment is recommended adding here about orographic influence on precipitation especially of the southern higher parts of the examined area. 

12. In References: The referenced citations text should not be underlined.

 

Author Response

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Author Response File: Author Response.pdf

Reviewer 5 Report

Comments and Suggestions for Authors

General comments:

·         Manuscript shows an interesting study on a relevant topic regarding sustainability and climate change, however it  needs better representation.

·         English style and vocabulary require corrections for improved readability and clarity.

·         Abbreviations and terms need clarification upon first use (e.g., NDVI, MODIS data, MVC method).

·         Research methods should provide exact equations, clarify terms (e.g., the meaning of "n" from line 129, clarification on "theta" and "E" in rate of change calculations).

Research Methods:

·         Eq 1 needs clarification, resembling Zhang 2016 (eq 7); more detailed explanation required on terms and rate of change (similar to my above point 4).

·         Potential unknown contributors to UF should be discussed, such as wind, landslides, floods.

·         Consider applying a simple graphical flow chart to enhance the visual structure of the methods section.

Specific Queries:

·         Lines 296-296 content seems more suitable for the Research Methods section.

·         Question the meaning of "k" and "R^2" in Figures 4 and 5; discuss the relevance of R^2 in the context of linear functions.

·         Challenge bold conclusions in section 3.4 based on the Hurst coefficient, considering its sensitivity to spatial scale in data averaging.

Figure 9 and Method Explanation:

·         Figure 9 is crucial; method for obtaining results (superimposing H index, NDVI trend, and significance) needs clarification.

·         Define what "superimposing" means – whether it involves simple addition or a more complex process.

·         Address the absence of an explanation for this critical step in the research methods section.

 

Miscellaneous:

Consider avoiding the use of "H index" due to potential confusion regarding the indicator of quality of work for academic author.

Question the significance of R^2 in determining positive or negative trends; its usefulness in light of dataset variations needs clarification.

It is a well-known phenomenon that the Hurst coefficient is directly positively influenced by the spatial scale on which the data series is averaged. This raises the question for the authors whether they are sure that lower values (and 0.41 is not that far from the threshold of 0.5) are the indicator of long-term persistence of data series or rather the result of the rather small spatial scale of 1kmx1km? This should be discussed.

 

To summarise, the manuscript needs to be improved in terms of presentation, language and clarity. Particular attention should be paid to the section on research methods, including equations and graphical presentation, as well as explanations of key figures and results. My main comment concerns Figure 9, which is important to address properly due to the potential implications for future land use planning decisions for the Yinshanbeilu grassland region.

Addressing these points will improve the overall quality and impact of the manuscript.

Comments on the Quality of English Language

English style and vocabulary require corrections for improved readability and clarity.

Author Response

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Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

The suggestions were made.