Quantifying the Contributions of Climate Change and Human Activities to Maize Yield Dynamics at Multiple Timescales

Round 1

Reviewer 1 Report

This manuscript is original and will be of interest to readers globally. The analysis is really novel and will be helpful to understanding factors of crop production at different time scales. The manuscript needs extensive edits with relation to the presentation of the english language. There are many areas/sentences of the paper that are awkwardly written and need editing. The Methods Section (2.2.1) has many undefined abbreviations. There are numerous sentences that begin with abbreviations, this should never be done, also there are sentences that begin with a conjunction (e.g., and, but, if, etc...) this should also never be done. The individual figures in Fig. 4 and Fig. 5 are far too small to see. The figures in Fig. 4 need to be identified, what is a), b), etc....? 

Specific edits.

Lines 31-38: this is an awkward, difficult to read paragraph and needs to be re-written.

Line 46: Scale should not be plural, should be "Single time scale analysis".

Line 56-57: should read, "....interaction had resulted in yield...."

Line 58: one decimal place is sufficient.

Line 58-60: this sentence is awkward, re-write.

Line 60-61: This sentence is awkward, re-write.

Line 63: replace "projects," with "practices".

Line 74: replace "characteristic" with "characterization".

Line 75: replace "Therefore, this" with "In this study we employ"

Line 76: delete "a"

Line 78: replace "physically reveal" with "quantify".

Line 82: Do not start a sentence with a conjunction "And".

Line 82-84: awkward sentence, re-write.

Line 84-87: awkward sentence, re-write.

Line 87-89: This sentence seems out of place.

Line 95-96: beginning with "It is .....be irrigated [41]. These sentences are out of place or perhaps not even needed.

Line 100: replace "crops" with "crop"; delete "Since its" and start the sentence with "Fertile".

Line 101-103 seems redundant with line 80-84.

Line 104: what is "mu"?

Line 110: do not start a sentence with "And". "The daily.....

Line 113: why is wet day precipitation defined as R95?

Equation 1 "c" and "r" not defined.

Check all abbreviations in section 2.2.

Line 138: replace "applyed" with "applied"

Line 142: define residue? This is a bit confusing. Was it supposed to be residual or error?

Lines 172-175: lettering is of "variance" is not in the same line;

Lines 179-188: same "simple variance" is not in the same line.

Line 191: begin the sentence with "The DVVD...."

Line 193: what was 3% used and not 2%, or 4%, or 5%? Justify.

Line 247: should this be "Table 2"?

Line 249, 251, and 255: Do not start sentences with abbreviations.

Figure 4 and Figure 5: too small hard to read.

Figure 4: what does a), b).....f) represent? Define in caption.

Table 3: in the text there is frequent reference to "long-term trend", this seems to be meaning "Residue" in the table. Is this correct?

Line 302: replace "had more sensitive" with "showed more sensitivity".

Line359: replace "underestimates" with "underestimate", not plural.

 

 

 

Author Response

Reviewer #1: This manuscript is original and will be of interest to readers globally. The analysis is really novel and will be helpful to understanding factors of crop production at different time scales. The manuscript needs extensive edits with relation to the presentation of the English language. There are many areas/sentences of the paper that are awkwardly written and need editing. The Methods Section (2.2.1) has many undefined abbreviations. There are numerous sentences that begin with abbreviations, this should never be done, also there are sentences that begin with a conjunction (e.g., and, but, if, etc...) this should also never be done. The individual figures in Fig. 4 and Fig. 5 are far too small to see. The figures in Fig. 4 need to be identified, what is a), b), etc....?

 

Response: We sincerely appreciate the reviewer for his/her thoughtful and encouraging comments on our manuscript, which we all think are valuable and constructive for improving our manuscript. According to the comment, we have revised the manuscript item by item.

 

(1) Lines 31-38: this is an awkward, difficult to read paragraph and needs to be re-written.

Response: Thanks for your help, and we are really grateful. According to the comments of reviewers, the author further revised the corresponding expressions (marked in red) in the revision. The specific modifications are displayed in the lines 31 – 37 of the revised manuscript.

1) Line 51. The "s" should be removed to the word "droughts"

Response: Corrected.

 

2) Line 46: Scale should not be plural, should be "Single time scale analysis".

Response: Corrected.

 

3) Line 56-57: should read, "....interaction had resulted in yield...."

Response: Corrected.

 

4) Line 58: one decimal place is sufficient.

Response: Corrected.

 

5) Line 60-61: This sentence is awkward, re-write.

Response: Corrected.

 

6) Line 63: replace "projects," with "practices".

Response: Corrected.

 

7) Line 74: replace "characteristic" with "characterization".

Response: Corrected.

 

8) Line 75: replace "Therefore, this" with "In this study we employ"

Response: Corrected.

 

9) Line 76: delete "a"

Response: Corrected.

 

10) Line 78: replace "physically reveal" with "quantify".

Response: Corrected.

 

11) Line 82: Do not start a sentence with a conjunction "And".

Response: Corrected.

 

12) Line 82-84: awkward sentence, re-write.

Response: Corrected.

 

13) Line 84-87: awkward sentence, re-write.

Response: Corrected.

 

14) Line 87-89: This sentence seems out of place.

Response: Corrected.

 

15) Line 95-96: beginning with "It is .....be irrigated [41]. These sentences are out of place or perhaps not even needed.

Response: Corrected. The author deleted these sentences.

 

16) Line 100: replace "crops" with "crop"; delete "Since its" and start the sentence with "Fertile".

Response: Corrected.

 

17) Line 101-103 seems redundant with line 80-84.

Response: Corrected. The author deleted these sentences.

 

18) Line 104: what is "mu"?

Response: Thanks for your help, and we are really grateful. According to the comments of reviewers, the author has converted the unit ‘mu’ into ‘acre’ (marked in red) in the revision. The specific modifications are displayed in the line 99 of the revised manuscript.

 

19) Line 110: do not start a sentence with "And". "The daily.....

Response: Corrected.

 

20) Line 113: why is wet day precipitation defined as R95?

Response: Thanks for your help, and we are really grateful. According to the comments of reviewers, the author has converted R95 into GEP (marked in red) in the revision. The specific modifications are displayed in the lines 15, 108, 227, 230, 233, 246, 247, 285, 287 and 322 of the revised manuscript.

 

21) Equation 1 "c" and "r" not defined.

Response: Corrected.

 

22) Check all abbreviations in section 2.2.

Response: Corrected. The author checked all abbreviations in section 2.2.

 

23) Line 138: replace "applyed" with "applied"

Response: Corrected.

 

24) Line 142: define residue? This is a bit confusing. Was it supposed to be residual or error?

Response: Thanks for your help, and we are really grateful. According to the comments of reviewers, the author defined the residue (marked in red) in the revision. The specific modifications are displayed in the line 73 of the revised manuscript.

 

25) Lines 172-175: lettering is of "variance" is not in the same line;

Response: Corrected.

 

26) Lines 179-188: same "simple variance" is not in the same line.

Response: Corrected.

 

27) Line 191: begin the sentence with "The DVVD...."

Response: Corrected.

 

28) Line 193: what was 3% used and not 2%, or 4%, or 5%? Justify.

Response: ​Thank you for your help, we are very grateful. Some scholars have found that despite significant advances in technology and crop yields, food production and safety remain deeply dependent on weather and climate change [1-3]. Firstly, climate factors have a significant impact on maize yield fluctuations [2, 3], the minimum value of the impact of climate factors on maize yield components is selected as the value principle of the threshold (e.g., the impact of GEP on IMF3 of maize yield); Secondly, the threshold value should not be too small. If the threshold value is too small, the sensitivity of influencing factors to maize yield components cannot be reflected. Overall consideration, this study takes the threshold as 3%. The impact of climate change and human activities on maize yield components is shown in Table 1 below.

Table 1 The sensitivity analysis of maize yield to climate change and human activities at different timescales based on the DVVD method.

	Original	IMF1	IMF3	r
GSMAT	1.08%	19.07%	0.02%	15.75%
GSMT	8.00%	25.91%	0.36%	15.66%
GST	0.93%	16.47%	1.31%	14.61%
GSP,	0.88%	2.55%	9.42%	4.47%
GEP	0	2.84%	3.62%	12.08%
CDD	13.15%	16.51%	37.15%	16.67%
EIA	23.72%	8.68%	2.36%	8.41%
CFF	52.26%	7.96%	45.52%	11.63%

 

Reference:

[1] Rosenzweig, C., Iglesias, A., Yang, X.B., Epstein, P.R. Chivian, E. Climate change and extreme weather events - implications for food production, plant diseases, and pests. Glob. Change Hum. Health. 2001, 2(2), 90-104.

 

[2] Richard, P., Hasenauer, H. Climate input parameters for real-time online risk assessment. Nat. Hazards, 2014, 70(3):1749-1762.

 

[3] Zou, J., Xie, Z., Zhan, C., Chen,F., Qin, P.H., Hu, T., Xie, J.B. Coupling of a Regional Climate Model with a Crop Development Model and Evaluation of the Coupled Model across China. Adv. Atmos. Sci. 2019, 36(5):527-540.

 

29) Line 247: should this be "Table 2"?

Response: Corrected.

 

30) Line 249, 251, and 255: Do not start sentences with abbreviations.

Response: Corrected.

 

31) Figure 4 and Figure 5: too small hard to read.

Response: ​Thank you for your help, we are very grateful. According to the comments of reviewers, the author redraw Figures 4 and 5 in the revision. The specific modifications are displayed in the lines 242 and 260 of the revised manuscript.

 

32) Figure 4: what does a), b).....f) represent? Define in caption.

Response: ​Thank you for your help, we are very grateful. According to the comments of reviewers, the author defined subgraphs of Figure 4 in the revision. The specific modifications are displayed in the line 243 of the revised manuscript.

 

33) Table 3: in the text there is frequent reference to "long-term trend", this seems to be meaning "Residue" in the table. Is this correct?

Response: ​Thank you for your help, we are very grateful. In the EMD proposed by Huang et al. [4] and improved EEMD method proposed by Wu and Huang [5], the residual term of the decomposed signal can be used as the long-term trend of the input signal. Therefore, based on the viewpoint of Huang et al. [4], the author utilizes the EEMD method to decompose the sequences such as maize yield, and the IMFS and residue obtained can be used as the long-term trend of the sequence.

 

Reference:

 

[4] Huang, N.E., Shen, Z., Long, S.R. The empirical mode decomposition and the Hilbert spectrum for nonlinear and nonstationary time series analysis. Proc. R. Soc. Lond. A. 1998, 454, 899-955.

 

[5]Wu, Z.H., Huang, N.E. Ensemble empirical mode decomposition: a noise-assisted data analysis method. Adv. Adapt. Data Anal. 2009, 1(1), 1-41.

 

34) Line 302: replace "had more sensitive" with "showed more sensitivity".

Response: Corrected.

 

35) Line359: replace "underestimates" with "underestimate", not plural.

Response: Corrected.

Author Response File: Author Response.pdf

Reviewer 2 Report

The manuscript entitled “Quantifying the Contributions of Climate Change and Human Activities to Maize Yield Dynamics at Multiple Timescales” is well written and interesting. The study is scientifically robust, and the data set extensive. The authors used EEMD method to extract maize yield, climate change and human activity at multiple time scales during 1979-2015. The effects obtained were then explored to provide scientific knowledge for food security. The results showed that the effect of human activities on the original sequence of maize yields has obscured the effect of climate change. This type of study provides better insights into maize yield dynamics affected by human activity and climate change, and therefore the results could be used to improve maize yield forecasting and modelling.

Only minor corrections should be made in this paper.

Specific comments:

In Introduction section the last sentence (lines 95-96) should be deleted.

 

In the Results section, the Table number should be changed (line 247). The Table 3 to which the authors refer in the text is actually Table 2.

Best regards

Author Response

Reviewer #2: The manuscript entitled “Quantifying the Contributions of Climate Change and Human Activities to Maize Yield Dynamics at Multiple Timescales” is well written and interesting. The study is scientifically robust, and the data set extensive. The authors used EEMD method to extract maize yield, climate change and human activity at multiple time scales during 1979-2015. The effects obtained were then explored to provide scientific knowledge for food security. The results showed that the effect of human activities on the original sequence of maize yields has obscured the effect of climate change. This type of study provides better insights into maize yield dynamics affected by human activity and climate change, and therefore the results could be used to improve maize yield forecasting and modelling.

Response: Thank you again for your time and effort, and for helping us improve the manuscript.

 

(1) In Introduction section the last sentence (lines 95-96) should be deleted.

Response: Corrected.

 

(2) In the Results section, the Table number should be changed (line 247). The Table 3 to which the authors refer in the text is actually Table 2.

Response: Corrected.

 

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Round 2

Reviewer 1 Report

Thank you for you attention to edits of this manuscript. There are additional comments for improvement annotated in the manuscript using Track Changes. Please pay special attention to the use of time scale and timescale in the manuscript. They mean different things and seem to be used interchangeably throughout the manuscript. Also, not use use of the term residual.

Comments for author File: Comments.doc

Author Response

Reviewer #1: Thank you for your attention to edits of this manuscript. There are additional comments for improvement annotated in the manuscript using Track Changes. Please pay special attention to the use of time scale and timescale in the manuscript. They mean different things and seem to be used interchangeably throughout the manuscript. Also, not use of the term residual.

Response: We sincerely appreciate the reviewer for his/her thoughtful and encouraging comments on our manuscript, which we all think are valuable and constructive for improving our manuscript. According to the comment, we have revised the manuscript item by item.

(1) Line 99: Should this actually be “per hectare”?

Response: Thanks for your help, and we are really grateful. The data used in this study were corn yield per unit area in Heilongjiang Province in kg/mu, which was converted into kg/acre by the author. Therefore, the use of "per acre" here is accurate.

 

(2) Line 125: Should this be “residual”?

Response: Thanks for your help, and we are really grateful. According to the comments of reviewers, the author changed the word "residue" in the whole article to "residual".

 

(3) Line 133: Should the EED be EEMD?

Response: Corrected.

 

(4) Lines 145-147: Fix the table alignment and text wrapping problem here.

Response: Corrected.

 

(5) Lines 161-162: Redundnat wit lines 161 and 162.

Response: Corrected.

 

(6) Line 300: Check time scale or timescale? Both have been used in the manuscript.

Line 317: Please check the entier manuscript for proper use of time scale and timescale or time scales.

Response: Thanks for your help, and we are really grateful. According to the comments of reviewers, the author changed the words "time scale" in the whole article to "timescales".

 

(7) Lines 306-307: It might be helpful for readers to distinguish human factors from climate factors in this figure by making the text for the human factors a different color than the climatic factors, for example, make the humane factor text EIA and CFF blue and leave the others black.

Response: Thanks for your help, and we are really grateful. According to the comments of reviewers, the author further revised the Figure 6 in the revision. The specific modifications are displayed in the lines 305-307 of the revised manuscript.

Author Response File: Author Response.pdf