Contrasting Effects of Temperature and Precipitation on Vegetation Greenness along Elevation Gradients of the Tibetan Plateau

Round 1

Reviewer 1 Report

The manuscript titled "Elevationally contrasting effects of temperature and precipitation on vegetation greenness across the Tibetan Plateau" presented a work on the regulation of temperature and precipitation on vegetation ecosystems. It is very useful to understand the climate applications.

The manuscript is clearly written and organized. In addition to the organization, the results are clearly presented and discussed. However, in overall, after reading the manuscript, I felt there are few minor things which needs clarification.

1. The Introduction and literature review section can be elaborated considering the most recent works.
2. In addition, it would nice, if author(s) could introduce a small section in the introduction highlighting the key contributions. (I am being specific here based on the topic of interest with the community, as it a climate and global weather related one, many policy makers, IPCCC etc would be interested in reading, so please highlight the key contributions)
3. In many places, just after the equations, the notations are briefly presented, but author(s) failed to give the units. (for example, h is altitude, so its units can feet, meters etc.) Please check manuscript carefully and provide units for all notations wherever it is applicable. 
4. As I mentioned earlier in Point 1, the author(s) should refer to most recent works (2016,17,18,19, 20). I knew that, the data used in this study is up to 2015, but literature study can be extended to 2020.

Author Response

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Author Response File: Author Response.docx

Reviewer 2 Report

A nice paper to show NDVI relationship with temperature and precipitation.

Author Response

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Author Response File: Author Response.docx

Reviewer 3 Report

This manuscript provides insights on the contrasting impacts on temperature and precipitation on vegetation greenness over the Tibetan Plateau. The research is quite interesting and the manuscript is well prepared. However, I two main questions. However, I recommend publishing the manuscript after addressing the below remarks. 

1. The authors stated that most of the studies on this issue have focused on the temperature effect and did not put lots of emphasize in precipitation effect. I think this is not entirely true, as a quick search can result in many previous studies that analyzed the impact of precipitation. Below are some examples: 

   https://doi.org/10.1111/gcb.12961

   https://doi.org/10.1029/2019JD030481

   https://doi.org/10.1038/s41598-020-57910-1

   https://doi.org/10.1007/s00376-018-7064-3

   https://dx.doi.org/10.3390%2Fijerph16234709

2. How did the authors deal with the different spatial resolutions of the several datasets used in the current analysis? Did you unify the resolution in order to provide a robust correlation between the variables? 
3. Can you discuss your results in view of a previously published paper by Zhang et al., 2019?

   https://dx.doi.org/10.3390%2Fijerph16234709

4. Lines 109-111: Why did you use two NDVI values (0.1 and 0.4) to define vegetated areas? For this, you need either to cite references or to show how did you come with the thresholds from your own analysis. 
5.  I think the manuscript can benefit from some language editing. 

6. Line 49: 2.5 × 10⁶ km² instead of 2.5 × 106 km²

7. Line 119: 51 100-m is This figure correct?

8. Line 123: then instead of than

Author Response

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Author Response File: Author Response.docx

Reviewer 4 Report

The manuscripts titled “Elevationally contrasting effects of temperature and precipitation on vegetation greenness across the Tibetan Plateau” reports an investigation of NDVI in the Tibetan Plateau based on remote sensing products. Overall, it provides a detailed analysis, although not earth breaking. Its novelty is not explicit to me. Maybe need a paragraph in the introduction or conclusion to emphasize it.

My comments:

1. The analysis using different NDVI and Precipitation products at different resolutions seems to be an addition to the research topic. I won’t expect any significant difference between results from different products. Instead, as a reader, I would like to see some in-depth analysis of the spatial pattern and time-series analysis. For example, at Lines 355-356, this paper could explore more to support this statement that biotic and abiotic factors affect the elevational movement of greenness.
2. Lines 110-111: How do you determine these thresholds for NDVI, any reference, or investigation? If other values are selected, how will your results change accordingly?
3. Line 141, the coefficient of Pgs(h) is not defined in the text.
4. English should be polished. I found several obvious typo and grammar errors throughout the texts, e.g., Line 306 “CO2”, Line 221, “the rates was about 10 m/ year.”

Author Response

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Author Response File: Author Response.docx

Round 2

Reviewer 4 Report

Thanks for your great work and detailed response to my comments.