Comparison of the Radial Growth Response of Picea crassifolia to Climate Change in Different Regions of the Central and Eastern Qilian Mountains

Round 1

Reviewer 1 Report

This work is suitable for Journal scope analyzing climate growth relationships in different Central and Eastern Qilian Mountains regions. Several issues must be improved before acceptance for publication. The English is poor and needs to be revised, and the following punctiform aspects need to be solved:

 

L11 – Please change “established” with “constructed”

L18 – pleased change “is significantly” with “was significantly”.

L36 – please change the reference “Jiao, L.; Jiang, Y.; Zhang, W.-T.; Wang, M.-C.; Zhang, L.-N.; Zhao, S.-D. Divergent responses to climate factors in the radial 467 growth of Larix sibirica in the eastern Tianshan Mountains, northwest China. Trees 2015,29, 1673-1686. 468 https://doi.org/10.1007/s00468-015-1248-6” with “IPCC (Intergovernmental Panel on Climate Change) (2001) Climate Change 2001: Synthesis Report. A contribution of working groups I, II and III to the third assessment report of the Intergovernmental Panel on Climate Change (ed. by R. T. Watson and the Core Writing Team). Cambridge University Press, Cambridge, UK.”

L60 – please add a space after “In contrast,”

L102 – please add space after the ending phrase.

L105 – please change “we established” with “we constructed”

L109 –space is needed after “3)”

L123 – a dot is missing after “respectively”

L125 – please explain the “a” in the sentence “6.01mm/10a”

L138 --Figure 3 - please add space in the figure label between explanation and units, e.g. Precipitation and (mm). Also, the correct unit must be (mm/year)

L136 - Interannual variabilities of the mean maximum, mean minimum, mean temperatures, and total precipitation for 1957-2018 in three Central and Eastern Qilian Mountains regions.

L138 - Figure 3. Monthly mean maximum, mean minimum, mean temperatures, and total precipitation, during1957-2018 in the three Central and Eastern Qilian Mountains regions.

L139 – please ad space in the sentence “during1957-2018”

L141 – please change “were collected using grid data from CRU TS4.04 (land) covering the study area from 1957 to 2018” with “were extracted fromCRUTS4.04 climate datagrid for the period 1957-2018”

L159-160 – please change “drill holes” with “increment borer”

L161- please change “taken” with “investigated”

L162 – Table 1. Would you mind double-check the space between “Table 1” and “Information about ….” Also, the capitalization of “Information”. In the table explanation, please add information regarding “CC(%), TD(m), DHB9cm) and TH(m).

L164, L165 – please delete “sample”

L170 -L172. The standardization method selected in your study is unclear justified. It is difficult to understand what you have used: exponential curves or linear regression…

L220 – space after Figure 4 is needed…

Would you please double-check the use of short line (-), and medium line (‒) throughout the manuscript and be consistent? It appears confusion between the minus sign and the line between numbers.

L221 - L227 increasing trend with an increasing rate / decreasing trend with a decreasing rate = these sentences are confusing, broadly explaining the direction and rate of similar action; please rephrase.

L228 – Figure 4 – Please change the figure “Number” with “Sample depth” and the “year” with “Year”.Also, a similar font for all numbers in x and y axes for all panels. I suggest increasing the x axe count the numbered axis is very crowded. In the figure caption, please indicate “Interannual variabilities of tree ring width and basal area increment (BAI) in the three Central and Eastern Qilian Mountains regions.

L231- L232 “Figure5 shows the correlation between the radial growth of Qinghai spruce. And climatic factors in the three regions.” I suggest this version “The correlation between radial growth of Qinghai spruce and climatic factors are illustrated in Figure 5.”

L233 – please change “R” with standard used “r” indicating the correlation relationship and be consistent in the manuscript.

L237 – “However, But” please delete one of these words

L244 - Figure 5. Correlations between tree-ring width chronologies and climatic factors in the three Central and Eastern Qilian Mountains regions.

L250 – There are two verbs, “please double-check”

L252 – “of the growing season of the current year” please change “current year growing season”

L259 - Figure 6. Correlations between tree-ring width chronologies and standardized precipitation evapotranspiration index (SPEI) in the three Central and Eastern Qilian Mountains regions.

L263 – please ad dot at ending line

L298 – please change “conclusion” with “founding”

L436 – please add dot between this words “climate Therefore”

L437 – also, between “region However”

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 2 Report

Dear Authors,

Please find the comments in the attached file

Regards

Comments for author File: Comments.pdf

Author Response

Response to Reviewer 2

Dear Authors,

Please find the comments in the attached file

Regards

1) I think you could mention here something from the methods part before going to the main conclusions

Thank you for your suggestion. We've added some method notes in the manuscript. We use Pearson correlation and moving correlation to analyze the main climate factors limiting radial growth of trees and the temporal stability of the growth-climate relationship, while spatial correlation is the result of further testing the first two terms in space. (Please see lines 12-14).

2) Do you need this task, because I found no results answering this research question.

Answer:

Many thanks for the careful review and the constructive comments. As for the future trend of tree growth, there is no in-depth study in this manuscript. But a simple explanation of the future trend of tree growth is made from the response relationship between tree growth and climate and the mechanism of tree growth under different regional climate background (Please see lines 444-446).

3) You do not need to write conclusions here right?

Answer:

Thanks! We have fully accepted your suggestion. And we have deleted this conclusion here to make the writing more scientific and standard.

4) Please relate your research tasks with materials and methods, now it is difficult to find which method belong to which research task.

Answer:

Thanks! We have modified the manuscript according to your suggestions. We specially added the method description in the second part as follow: (Please see lines 138-147).

 

To test the growth-climate relationship, we calculated the Pearson correlation coefficients between tree-ring width chronologies of the trees in three regions during 1957-2018. Additionally, we accurately depicted the growth-climate temporal relationship with a moving correlation function using DendroClim 2002. We employed a fixed 30-year period starting from 1957 that slid across time to compute the correlation coefficients between tree-ring and climate factors in tree regions. Finally, we also calculated the spatial Pearson correlation with the Climate Explorer website(http://climexp.knmi.nl/) to estimate the stability of radial growth responses and test the accuracy of the moving correlation results. Spatial Pearson correlations reflect large-scale response patterns driving the radial growth of trees.

36. Biondi, F.; Waikul, K. DENDROCLIM2002: A C++ program for statistical calibration of climate signals in tree-ring chronologies. Comput geosci-uk 2004, 30, 303-311. https://doi.org/ 10.1016/j.cageo.2003.11.004.

5) I think you need more details here, don’t make readers to go to search for it in other publications.

Answer:

Thank you for your suggestion.We further supplement the explanation of "SPEI", so that readers can have a deeper understanding of the analytical value of this index in the article.Supplements as follow: The monthly standardized precipitation-evapotranspiration index (SPEI) were calculated using climate data (precipitation, temperature, relative humidity, solar radiation, water vapor pressure, and wind speed) for the analysis of the radial growth responses of trees to drought and the evaluation the effects of drought at different time scales on the radial growth of trees. (Please see lines 153-158).

6) How many cores did you take per tree, It seems that for some trees you take 2 samples and from other only 1, why?

Answer:

Thanks! According to the rules of sample sampling, each tree needs to collect two cores in the East-West and North-South directions.However, there are some reasons such as rotten core or tree-ring width is different from the main sequence, so some of are removed in the process of sample collection and processing.

7) You do not describe what means this P? Is it a sample plot or what?

Answer:

Thanks you for checking so carefully,and we neglected to add the explanation of "P". "P" means the sampling place of Picea crassifolia. Since the initial letter of Picea crassifolia is "P", we defined "P" as the sampling place. We will supplement the explanation of this letter in this article.

8) I think you have to clarify in detail how this parameter was calculated, formula would be useful.

Answer:

Thank you very much! The calculation of the STD chronology is the direct result of the ARSTAN software program, and there is no specific formula to show.Standardized chronology (STD) is a chronology obtained by standardizing the ring width, eliminating the growth trend related to tree age and the influence of individual differences of trees, and then eliminating the samples with poor correlation with most sequences according to the correlation coefficient between index series and main series, and finally combining the two weight average method. (Please see lines 184-188).

40. Helama, S. Expressing Tree-Ring Chronology as Age-Standardized Growth Measurements. Forest Sci 2015, 61, 817-828. https://doi:10.5849/forsci.14-139.

9) Please provide information which tool was used to calculate these statistical parameters.

Answer:

Thanks! Similar to the calculation process of the above-mentioned STD chronology, the ARSTAN software program also runs out the statistical parameters related to the chronology data with Rtot.

42. Ahmed, M.; Palmer, J.; Khan, N.; Wahab, M.; Fenwick, P.; Esper, J.; Cook, E. The dendroclimatic potential of conifers from northern Pakistan. Dendrochronologia 2011, 29, 77-88. https://10.1016/j.dendro.2010.08.007.
43. Yang, B.; He, M.; Melvin, T.M.; Zhao, Y.; Briffa, K.R. Climate control on tree growth at the upper and lower treelines: a case study in the Qilian Mountains, Tibetan Plateau. PLoS One 2013, 8, e69065.

10) Here it is quite confusing point. I think you should not use term radial tree growth in your manuscript but rather use basal area increase or simple abbreviation BAI. That would be more clear. Or add sentence clarifying that in your manuscript everywhere radial tree growth means BAI.

Answer:

Many thanks for the careful review and the constructive comments! We have used the “basal area increase” instead of “term radial tree growth” (Please see line 220). "Increase in sectional area" is an important reference to trees reflecting the growth trend of trees, but "radial growth" is a more scientific description, but "increase in sectional area" in this sentence is more scientific and reasonable.

11) Space needed

Answer:

Many thanks for the careful review! And we have added space after Figure 4. (Please see line 237)

12) Space needed

Answer:

Thanks you for checking carefully, and we have added space after Figure 5.

13) I think you need some sentences in methods part regarding these results. How it was calculated?

Answer:

Many thanks for the careful review and the constructive comments.The correlation between SPEI and radial growth is mainly calculated by Pearson correlation in SPSS software. We will supplement the explanation of the research method in this paper appropriately.

14) You need to describe in methods part how spatial correlations were estimated!!! Also which research task it is associated? Which tool was used to calculate it?

Answer:

Many thanks for constructive comments.We ignored the explanation of spatial correlation in the method description. In this paper, the spatial correlation result (Figure 5) is calculated on this website(http://climexp.knmi.nl/). Through the calculation of spatial correlation, we can know the spatial performance of the response relationship between radial growth and climate, and further analyze the main factors affecting tree growth in Qilian Mountain.This is also a supplement and expansion of Pearson's results above.

15) Why eastern region is missing here?

Answer:

Thanks! The correlation between tree growth and climate factors in the Eastern Qilian Mountains is not significant according to the Pearson correlation results in this manuscript.While the correlation results in the other two regions are more prominent. Therefore, the value of studying the spatial correlation in Eastern Qilian Mountains is not great as an extension of Pearson correlation results.

16) I think you have to define calculation procedure in your methods part. Presently, there is nothing there. Which tool was used to produce the figures?

Answer:

Many thanks for your suggestion. The moving correlation is calculated by placing chronological data and climate data in the software named “DendroCrim 2002” by setting the moving window to 30 years. After the program runs, the moving correlation results of 30 years are obtained. The results are used to analyze the time stability of the correlation between tree growth and climate factors.

17) Please clarify what black dots indicate in your graph.

Answer:

Thank you very much! The black spot indicates that there is a significant correlation between tree radial growth and climatic factors during this period.

18) Your research tasks were: 1) Compare the difference of growth patterns of Qinghai 107 spruce 2) Determine the main climate factors affecting the growth of Qinghai spruce and 108 their response stability 3)Predict the future growth trends of the Qinghai spruce

I think the main problem with your conclusions is that they do no not relate with your research tasks or at least 2 (monthly effects)and 3 task is not answered here.

Answer:

Many thanks for the careful review and the constructive comments.We also supplemented the contents of the conclusion and combined with the three questions raised at the beginning of the article to make the whole article more scientific and coherent.

 

Author Response File: Author Response.docx