Sensitivity of Vegetation on Alpine and Subalpine Timberline in Qinling Mountains to Temperature Change

Round 1

Reviewer 1 Report

The manuscript ID forests-605705 is a resubmission of the former manuscript ID forests-605705 which I reviewed some weeks ago. Overall the paper is improved but there are still some adjustments to be done through the text.

Positive things I detected
• A much clearer Introduction chapter was add
• An explanation why climate change is affecting forest systems and why NDVI can be useful to study the timberline dynamics seems to be added in the discussion section properly
• The methods are more understandable now
• the discussion is more focused on the study

Remaining shortcomings
• The paper is still too focused on China only and needs to be placed in a broader context to be also read by an international audience which should be the real aim of a research paper.
• The chapter concerning the spatial interpolation of climate is fragmented and not clear. For instance on L216 the interpolation method (O-Kriging) suddenly appears without any introduction about it. It is not easy to undertand this was the selected method
• What’s the real meaning of adding a fourth or fifth order polynomial curve on Figure 4 without explaining it? And even if explained, does it have a real sense? I suggest to add just a trend line (moving average) to summarise the trend graphically
• L462-470: The Authors refer to “certain studies” but no references are provided. Here references are mandatory. Then on L266 a reference is provided but not as MDPI requests

Author Response

Response to Reviewer 1 Comments

 

Thank you very much for your suggestions. We revised the article in detail according to each of your suggestions and replied to each of them.

 

Point 1: The paper is still too focused on China only and needs to be placed in a broader context to be also read by an international audience which should be the real aim of a research paper.

Response 1: This issue has been modified in the revised draft. In the introduction, the response research on climate change and forest ecosystem has been added. Meanwhile, the international related research has been enhanced, and the international popularity of this research has been described.

 

Point 2: The chapter concerning the spatial interpolation of climate is fragmented and not clear. For instance on L216 the interpolation method (O-Kriging) suddenly appears without any introduction about it. It is not easy to undertand this was the selected method

Response 2:

Kriging method, also known as spatial local interpolation method, is a method of unbiased optimal estimation of regionalized variables in a limited area based on the theory of variation function and structural analysis. Its essence is to use the original data of regionalized variables and the structural characteristics of variation function to make linear unbiased and optimal estimation of unknown samples. That is to say, Kriging method is a kind of linear unbiased optimal estimation of unknown sample points based on the data of some known sample points in the limited neighborhood of unknown sample points, considering the shape, size and spatial orientation of sample points, the spatial position relationship with unknown sample points, and the structural information provided by the variation function.

This issue has been revised and explained in the revised version.

 

Point 3: What’s the real meaning of adding a fourth or fifth order polynomial curve on Figure 4 without explaining it? And even if explained, does it have a real sense? I suggest to add just a trend line (moving average) to summarise the trend graphically

Response 3:

For this problem, adopt the expert opinion, add the moving average curve to figure 4 to represent the change trend, which has been modified in the revised version.

 

Point 4: L462-470: The Authors refer to “certain studies” but no references are provided. Here references are mandatory. Then on L266 a reference is provided but not as MDPI requests

Response 4:

Relevant references have been added to the revised version.

L266 is not a reference format, but an interpretation of the chronological sequence of Lake sedimentation and the study site.

Author Response File: Author Response.doc

Reviewer 2 Report

General comment :

The authors present a study to evaluate the Senssivity of vegetation on alpine and subalpine timberline to temperature change. From my understanding, the technical parts of this work were done carefully and correctly, following adequate approaches. The manuscript is well written and have a good structure. I appreciate the effort the author put in the originality of this experience. Therefore, the research question is very interesting. This study provides an important contribution in forest science.

 

However, this article has some weaknesses that could be improved that I list below:

 

- More keywords must to be added

- Some Figures are blurry. Thus, Figures has not enough quality.

- The hypothesis are not presented.

- Result section is very long.

- In the introduction and discussion, doesn’t describes the international context. Also, in the discussion is lacking the management implication and recommendations for the future

- Many Figures…

 

I have also provided the following specific suggestions that would help to improve the quality of this manuscript. At this stage, I propose the authors to consider these suggestions in a moderate revision, and request the editor not to accept the manuscript until and unless the authors make the changes. I encourage the author to incorporate these suggestions, and I want to say congratulations for this interesting and original research.

 

Specific comments

 

Keywords: Keywords must to follow alphabetic order. modify it, please. Also, you could add other keywords as sustainable forest management, remote sensing, NDVI, natural disturbances, dendroecology. Remove the keywords that you repeated in your title: e.g. Qinling mountains… Introduction:

L44: Before to present Alpine Timberline. I suggest start the introduction talking about climate change versus forest ecosystems. Climate change is not only affecting timerline. You could talk about other changes: natural disturbances, distribution area of species… You could say that disturbances frequency and severity will increase under climate change in forest ecosystems. This could help to improve the international scopus of this paper. Please add here theses references:

Seild et al. 2017. Forest disturbances under climate change. Nature Climate Change. Navarro, L., Morin, H., Bergeron, Y., and Montoro Girona, M. (2018). Changes in spatiotemporal patterns of 20th century spruce budworm outbreaks in eastern Canadian boreal forests.  Plant Sci. 9:1905. doi: 10.3389/fpls.2018.01905

L61-68. You are describing a study: simplify it and add more references please

L69-70: Many abreviations: ITEX, OTC,… I think that these abreviations are not necessary here.

L82-83: 96.3 (one decimal), 31.42 (2 decimals)… one or two but not both decimals… to be cosistent

L100-106 : I like the objective style. However, I recommended the author to explain, justify and present the hypothesis.

L110: Nice Figure but it is a bit blurry… solve it, pleae.

L111-112: (a)Quinling… (b)Niubeilang.. (c)Tabai.. Add a space after (), please

L137: Cand… add space here.

L146: replace Data sources by data compilation, please

L161-163: Add reference of a study that use it!

174: table1: space is lacking. The same for other tables and figures

Table 1: replace lake by Lake.

Figure 2: Many labels.. overlapping and blurry… solve it, please.

L194: Replace it by location of study sites

Figure 3: very nice!

Results section is so long… reduce and simplify it, please!

Figure 4: blurry, difficoult to read… Remove the equations, please, b) years in X axis is overlapping with the graph… solve it!

L277 remove space after (a).

Figure 5. Nice Figure, but blurry. Month labels are very small… zoom it!

Figure 6: Great!

Figure 9: remove this Figure. Not important and low quality.

Discussion: Good! However, Authors must to add references, management implications is lacking, future recommendations and some study limitations. I suggest:

Start the discussion talking about climate change-international context and after present your major contribution. 435-449: any reference? 462-464: Which studies? Add references 476-492: any references? Figure 11: remove it!

Conclusion: Very nice.

L503-504: . Add the following references:…lake sediments and tree ring chonology (REFERENCES here),…

Girona M, Rossi S, Lussier J-M, Walsh D, Morin H (2017) Understanding tree growth responses after partial cuttings: A new approach. PLoS ONE 12(2): e0172653. https://doi.org/10.1371/journal.pone.0172653

Montoro Girona, M.; Morin, H.; Lussier, J.-M.; Walsh, D. Radial Growth Response of Black Spruce Stands Ten Years after Experimental Shelterwoods and Seed-Tree Cuttings in Boreal Forest. Forests 2016, 7, 1-20, doi:10.3390/f7100240.

Montoro Girona, M., Navarro, L., & Morin, H. (2018). A secret hidden in the sediments: lepidoptera scales. Frontiers in Ecology and Evolution, 6, 2.

L518-522: The size of police is different! Solve it!

Author Response

Response to Reviewer 2 Comments

Thank you very much for your suggestions. We revised the article in detail according to each of your suggestions and replied to each of them.

 

Point 1: More keywords must to be added

Response 1: Revised in draft.

 

Point 2: Some Figures are blurry. Thus, Figures has not enough quality.

Response 2: Revised in draft.

 

Point 3: Result section is very long.

Response 2: The result part has been reduced in the modification.

 

Point 4: In the introduction and discussion, doesn’t describes the international context. Also, in the discussion is lacking the management implication and recommendations for the future

Response 2:

Revised in draft. In the introduction, the impact of climate change on forest ecosystem and related literature were added, which reduced the regional research in China and strengthened the international research. At the end of the discussion, suggestions and measures for forest management were added

 

Point 5: Many Figures…

Response 2: Figure 9 and Figure 11 have been deleted

 

Point 6: Keywords must to follow alphabetic order. modify it, please. Also, you could add other keywords as sustainable forest management, remote sensing, NDVI, natural disturbances, dendroecology. Remove the keywords that you repeated in your title: e.g. Qinling mountains…

Response 2: Revised in draft

 

Point 7: L44: Before to present Alpine Timberline. I suggest start the introduction talking about climate change versus forest ecosystems. Climate change is not only affecting timerline. You could talk about other changes: natural disturbances, distribution area of species… You could say that disturbances frequency and severity will increase under climate change in forest ecosystems. This could help to improve the international scopus of this paper. Please add here theses references: Seild et al. 2017. Forest disturbances under climate change. Nature Climate Change. Navarro, L., Morin, H., Bergeron, Y., and Montoro Girona, M. (2018). Changes in spatiotemporal patterns of 20th century spruce budworm outbreaks in eastern Canadian boreal forests.  Plant Sci. 9:1905. doi: 10.3389/fpls.2018.01905

Response 2: Revised in draft. In the introduction, the impact of climate change on forest ecosystem and related literature were added, which reduced the regional research in China and strengthened the international research.

 

Point 8: L61-68. You are describing a study: simplify it and add more references please

Response 2: Revised in draft.

 

Point 9: L69-70: Many abreviations: ITEX, OTC,… I think that these abreviations are not necessary here.

Response 2: Revised in draft.

 

Point 10: L82-83: 96.3 (one decimal), 31.42 (2 decimals) … one or two but not both decimals… to be cosistent

Response 2: Revised in draft.

 

Point 11: L100-106 : I like the objective style. However, I recommended the author to explain, justify and present the hypothesis.

Response 2: The scientific hypothesis has been added to the last paragraph of the introduction and marked in red in the revised version. L91-98

 

Point 12: L110: Nice Figure but it is a bit blurry… solve it, pleae.

Response 2: Revised in draft

 

Point 13: L111-112: (a)Quinling… (b)Niubeilang.. (c)Tabai.. Add a space after (), please

Response 2: This has been modified as required

 

Point 14: L137: Cand… add space here.

Response 2: Revised in draft

 

Point 15: L146: replace Data sources by data compilation, please

Response 2: Revised in draft

 

Point 16: L161-163: Add reference of a study that use it!

Response 2: Added to revision, see references 17, 18.

 

Point 17: 174: table1: space is lacking. The same for other tables and figures

Table 1: replace lake by Lake.

Figure 2: Many labels. overlapping and blurry… solve it, please.

Response 2: These problems have been revised in the revised version.

The author provides the original pictures of each picture. Some pictures will be reduced in word, so it will be unclear. The author will provide all the original pictures after changing the font size. Figure 2 is the footprints of field investigation, Some investigation points will overlap after the pictures in word are reduced

 

Point 18: L194: Replace it by location of study sites

Response 2: Modified in revision.

 

Point 19: Results section is so long… reduce and simplify it, please!

Response 2: The result part has been reduced in the modification.

 

Point 20: Figure 4: blurry, difficoult to read… Remove the equations, please, b) years in X axis is overlapping with the graph… solve it!

Response 2: Modified in revision

 

Point 21: L277 remove space after (a). Figure 5. Nice Figure, but blurry. Month labels are very small… zoom it!  Figure 6: Great!  Figure 9: remove this Figure. Not important and low quality.

Response 21: All questions have been revised in the revised version.

 

Point 22: Discussion: Good! However, Authors must to add references, management implications is lacking, future recommendations and some study limitations. I suggest: Start the discussion talking about climate change-international context and after present your major contribution. 435-449: any reference? 462-464: Which studies? Add references 476-492: any references? Figure 11: remove it! Conclusion: Very nice.

Response 22:

In the first paragraph of the discussion, the discussion of global climate change has been put at the end of the summary of the results of the paper. Lines 435-449 mainly describe the results of the study and do not involve references;

Lines 462-464 have added references to citation studies, see references 5, 30, 31, 32; lines 476-492 have cited references 34;

Figure 11 has been deleted as required.

 

Point 23: L503-504: . Add the following references:…lake sediments and tree ring chonology (REFERENCES here),…Girona M, Rossi S, Lussier J-M, Walsh D, Morin H (2017) Understanding tree growth responses after partial cuttings: A new approach. PLoS ONE 12(2): e0172653. https://doi.org/10.1371/journal.pone.0172653

Montoro Girona, M.; Morin, H.; Lussier, J.-M.; Walsh, D. Radial Growth Response of Black Spruce Stands Ten Years after Experimental Shelterwoods and Seed-Tree Cuttings in Boreal Forest. Forests 2016, 7, 1-20, doi:10.3390/f7100240.

Montoro Girona, M., Navarro, L., & Morin, H. (2018). A secret hidden in the sediments: lepidoptera scales. Frontiers in Ecology and Evolution, 6, 2.

Response 23: Modified in revision.

 

Point 24: L518-522: The size of police is different! Solve it!

Response 24: Modified in revision.

 

Author Response File: Author Response.doc

This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.

Round 1

Reviewer 1 Report

Dear Authors, the manuscript "Sensitivity of Vegetation on Alpine and Subalpine Timberline in Qinling mountains to Temperature Change" is dealing with an important topic of wide interest for the scientific community. However, there are several flaws in the research presented. Methods are not well described, and results interpretation is quite strange. Furthermore your manuscript still appears rather compromised by inadequate English style, that generates potential shortcomings in the construction and in the reading of the manuscript. Therefore I strongly suggest you make use of a professional copy editing service or a native English speaker. Also the manuscript structure needs to be revised with a clear separation between results and discussion. The graphs should be enhanced in order to be more informative (e.g. the significant positive correlation line in fig.8…..). The reference format is not always correct, species scientific names should be in italic. References selection is not the best for the topic, there are several international papers that you can find to improve your discussion and results interpretation.

One of your statements it cannot be correct: in line 247-249 you are saying that vegetation growth in the previous year is affecting the temperature in the year after. This cannot be found from your data. When dealing with correlation values you have always to consider the presence of spurious correlation….. Temperature is not consistently rising because the vegetation growth the year before, but since climate is working like this.

The discussion is not really a discussion. You should discuss your results, not simply report other papers results.

I think you have a nice dataset, and potentially great information can come out from that, but you are still far from that. For these reasons I think the paper is not suitable for publication in its current version.  

Some further remarks (only some, list not exhaustive):

Line 38: latin name in italic

Line 39: are not ae

Line 48: “Zhang Lije studied” not a correct format for citing a study (all over the manuscript)

Line 75: 10?

Lines 78-80: what is correlated with what?

Line 92: 3S: explain

Line 94: timberline spatial law?

Lines 98-105: this is not part of the introduction

Lines 123-124: Define “typical timberline-like areas”

Line 126: do not provide altitude with decimal

Line 128: The average vertical decline? You mean each 100 m?

Line 144: verb is missing

Line 147: define “typical sample plots”

Line 163: Kring?

Line 171-179: here you are providing basic statistical information that are superfluous

 

Reviewer 2 Report

General comment and remarks
While the paper is interesting with an impressive amount of data analysed I believe many adjustments should be done prior publication. In my opinion the paper is too technically written and not organic as necessary for a research article. What I mean is that, for instance, the introduction is more a list of research outputs coming from other research groups more than an explanation why climate change is affecting forest systems and why NDVI can be useful to study the timberline dynamics. The same can be said for the discussion where, in my opinion, a real discussion on the obtained results is missing. Then the paper is too focused on China only and needs to be placed in a broader context to be also read by an international audience which sould be the real aim of a research paper...
I suggest some changes here listed.

Specific comments
ABSTRACT
I suggest to remove the numbers to make a unique speech more than a masked group of bullet points

INTRODUCTION
Even if (probably) true, the first sentence is too dramatic for a scientific journal
L49: use italic for latin name of forest tree species
L104-1055: too early to present your findings

MATERIALS AND METHODS
L123: check the font
L128: why you need to write “celsius degrees”? You can write 0.4 °C and 0.5 °C
L168: do you have a value and a reference to support you “allowable norm”?
L170-179: I suggest to completely remove this part which is well know for any researcher

RESULTS
To call figures you used both “Fig. N” and “Figure N”. Please standardise your paper. Then while figure 4 is never cited there are two Figure 10. Then are your regressions in Figure 3 and 4 statistically significant?

DISCUSSION
For this section I have similar observations to what I wrote into the introduction. It is too general, fragmented, not focused on your data and the meaning of your research

CONCLUSIONS
Nothing to say

Reviewer 3 Report

Please find my comments in the attached PDF document.

Comments for author File: Comments.pdf