Contribution of the Order Ericales to Improving Paleoclimate Reconstructions

Round 1

Reviewer 1 Report

General Comments:

• I’m not sure if this journal is the appropriate choice for this manuscript. It seems like it would be more appropriate for a journal focused on Paleobotany and/or paleoclimate.
• There is discussion about using this study for paleoclimate. It would be good to have some background information on the geologic range of the Order Ericales. What time intervals can this be used for in the fossil record?
• it is not clear to me what “woody dicotyledonous across-species” means. This is awkward wording. It sounds like how does woodiness varies across different species? I don’t think this is what the authors mean and this needs to be clarified since it is throughout paper.
• Authors need to establish what r-squared values they consider to be significant up front in the paper, before results, and justify the significance level they choose by citing previous similar studies. The highest r-squared value reported in section 3.1 is r-squared = 0.48, which seems low. However, maybe this isn’t low based on other studies but the authors need to explain the normal range of values found in similar studies.

Line #: Comment

13: it is not clear to me what “woody dicotyledonous across-species” means.

14-15:  need to define WDS and WDS-E before using abbreviations

20-21: need to define MART, MAP, and MAT before using abbreviations

45-48: sentences start with However, But, However. Try to limit use of these words for starting sentences

50-51: Genus and species names need to be italicized. Here it is A. rubrum  and Q. kelloggii. This needs to be fixed throughout manuscript and I will not point out the other times so that authors will need to find all names to be italicized.

54: avoid using the word proved.  Instead say Studies also showed…

58: remove also

63: what other patterns? Give examples

65: what is the ‘other pattern’ you refer to here?

67: with its members distributed

77: This study will test: (1) ….

90: is there new data in this paper, or is it all from a pre-existing dataset?

91: what characters? I would like to know exactly what features of the leaves are used. What are the 27 variables??

109: all other abbreviations are defined here, but not MAP. MAT, MART, and MAP were all defined in first paragraph. GSP is the only one defined here for the first time. I recommend defining all abbreviations once in the first paragraph and then not defining again to avoid redundancy.

111: extra spaces on this line

122: models {22    there is a space missing

133: missing space

136: should p be italicized?

138: space missing before reference; I will not point out this in following parts of the manuscript. The authors need to make sure they are consistently adding a space before the references.

141: should r be italicized?

153: R as in the R statisitcal package? Need to explain this better and say what version you used

154: MASS has yet to be defined as an abbreviation

165: what is RMSE? Not defined

172: sub-data

182-187: various short paragraphs that need to be combined into a larger paragraph. Try not to start a paragraph with a lowercase r-squared.

Line 202: what is the threshold used for a significant positive correlation? That should be defined in the methods. These r-squared values seem low to me.

Line 207: not sure what is meant by woody dicotyledonous here. Is this in reference to one of the models?

222: extra colon to delete

226: Figure. 5     delete ‘

272: Ericales

290 two classes models? Two class-models?

298: don’t use word proved. Don’t have a single-sentence paragraph

302-303: modern

319: probably? Awkward wording

331: extra period

339: for

Author Response

Mar 20, 2022 

Dear reviewer,

Thank you very much for your valuable comments and suggestions concerning our manuscript entitled “Contribution of the order Ericales to improving paleoclimate reconstructions”. We have studied comments carefully and have made corrections in the paper. The revised manuscript has been improved as a result of your constructive advice.                                                                                                                                                                                                                                                                   The following outlines the changes we have made point by point.

General Comments:

1. I’m not sure if this journal is the appropriate choice for this manuscript. It seems like it would be more appropriate for a journal focused on Paleobotany and/or paleoclimate.

Response: Thank you for your advice. This manuscript was submitted under the section “Air, Climate Change and sustainability”.

“With global warming and the frequent occurrence of extreme weather (such as drought), climate change is becoming the main threat to the sustainable development of human beings in the next few decades. Accurate paleoclimate estimation can help scientists to study and understand how environmental factors, such as greenhouse gases in the atmosphere, affect the earth's climate over time. Then, they can develop models to help predict how the increase of greenhouse gases and other changes may affect the future global climate. This will help the government to formulate sustainable development measures” (Please see lines 23-30).

So we think our manuscript is appropriate for this journal.

2. There is discussion about using this study for paleoclimate. It would be good to have some background information on the geologic range of the Order Ericales. What time intervals can this be used for in the fossil record?

Response: Thank you for pointing this out. We have revised it as suggested.

We have added some background information on the geologic range of the order Ericales (Please see lines 63-68).

We also have given the time intervals that WDS-E model can be used in the fossil record based on other similar studies (Peppe et al., 2011; Seyfullah, 2012) (Please see lines 274).

Peppe, D.J.; Royer, D.L.; Cariglino, B.; Oliver, S.Y.; Newman, S.; Leight, E.; Enikolopov, G.;  Fernandez-Burgos, M.; Herrera, F.; Adams, J.M.; Correa, E.; Currano, E.D.; Erickson, J.M.; Hinojosa, L.F.; Hoganson, J.W.; Iglesias, A.; Jaramillo, C.A.; Johnson, K.R.; Jordan, G.J.; Kraft, N.J.; Lovelock, E.C.; Lusk, C.H.; Niinemets, U.; Penuelas, J.; Rapson, G.; Wing, S.L.; Wright, I.J. Sensitivity of leaf size and shape to climate: global patterns and paleoclimatic applications. New Phytol. 2011, 190, 724–739.

Seyfullah, L. Fossil Focus: Using plant fossils to understand past climates and environments. Palaeontology Online, 2012, Volume 2, Article 7, 1-8.

3. it is not clear to me what “woody dicotyledonous across-species” means. This is awkward wording. It sounds like how does woodiness varies across different species? I don’t think this is what the authors mean and this needs to be clarified since it is throughout paper.

Response: Thank you for pointing this out. We are very sorry for this unclear expression and we have changed it to “woody dicotyledonous species”. For example, the sentence “Paleobotanists have long built leaf climate models based on site mean of leaf physiognomic characteristics of woody dicotyledons species (WDS) for estimating past climate.” (Please also see lines 10-11). 

4. Authors need to establish what r-squared values they consider to be significant up front in the paper, before results, and justify the significance level they choose by citing previous similar studies. The highest r-squared value reported in section 3.1 is r-squared = 0.48, which seems low. However, maybe this isn’t low based on other studies but the authors need to explain the normal range of values found in similar studies.

 Response: Thank you for pointing this out. The statistically significant of r-squared value is measured by P-value. Generally, when the P-value is no more than 0.05, the statistical correlation is considered to be significant (Royer et al., 2008) (Please also see line 109) .

In the similar study of Peppe et al. (2011), percent of untoothed species has the highest r-squared value with mean annual temperature (MAT) (r² = 0.58, P < 0.001), r-squared values of other leaf physiognomic variables with MAT are concentrated in 0.2~0.4 (P < 0.05; In fact, the second highest r² is 0.37). There are similar results in the study of Royer et al. (2008).

In the study of Peppe et al. (2011), only several physiognomic variables correlated significantly with mean annual precipitation (natural logarithmic transformed), the highest r² is 0.24, other r² are between 0.05 and 0.2 (P < 0.05).

The normal range of r² of physiognomic variables and growing season precipitation (GSP) is 0.05 to 0.16 (P < 0.05) (Peppe et al. 2011).

The normal range of r² of physiognomic variables and mean annual range in temperature (MART) is 0.1 to 0.3 (P < 0.05) (Peppe et al. 2011). 

Peppe, D.J.; Royer, D.L.; Cariglino, B.; Oliver, S.Y.; Newman, S.; Leight, E.; Enikolopov, G.;  Fernandez-Burgos, M.; Herrera, F.; Adams, J.M.; Correa, E.; Currano, E.D.; Erickson, J.M.; Hinojosa, L.F.; Hoganson, J.W.; Iglesias, A.; Jaramillo, C.A.; Johnson, K.R.; Jordan, G.J.; Kraft, N.J.; Lovelock, E.C.; Lusk, C.H.; Niinemets, U.; Penuelas, J.; Rapson, G.; Wing, S.L.; Wright, I.J. Sensitivity of leaf size and shape to climate: global patterns and paleoclimatic applications. New Phytol. 2011, 190, 724–739.

Royer, D.L.; McElwain, J.C.; Adams, J.M.; Wilf, P.Sensitivity of leaf size and shape to climate within Acer rubrum and Quercus kelloggii. New Phytol. 2008. 179, 808–817. 

Line #: Comment

1. 13: it is not clear to me what “woody dicotyledonous across-species” means.

Response: Thank you for pointing this out. We have modified this unclear expression. For example, “Paleobotanists have long built leaf climate models based on site mean of leaf physiognomic characteristics of woody dicotyledons species (WDS) for estimating past climate”. (Please see lines 10-11).

2. 14-15:  need to define WDS and WDS-E before using abbreviations

   Response: Thank you for pointing this out. We have revised it as suggested (Please see lines 11-13).

3. 20-21: need to define MART, MAP, and MAT before using abbreviations

  Response: Thank you for pointing this out. We have revised it as suggested (Please see lines 14, 15, 17).

4. 45-48: sentences start with However, But, However. Try to limit use of these words for starting sentences

 Response: Thank you for pointing this out. We have revised it as suggested (Please see lines 46-49).

50-51: Genus and species names need to be italicized. Here it is A. rubrum  and Q. kelloggii. This needs to be fixed throughout manuscript and I will not point out the other times so that authors will need to find all names to be italicized.

 Response: Thank you for pointing this out. We have checked our manuscript and revised it as suggested (Please see lines 50-51).

5. 54: avoid using the word proved.  Instead say Studies also showed…

 Response: Thank you for pointing this out. We have revised it as suggested (Please see lines 54, 261). 

6. 58: remove also

 Response: Thank you for pointing this out. We have revised it as suggested (Please see line 56). 

7. 63: what other patterns? Give examples

 Response: Thank you for pointing this out. Other patterns means not interspecific patterns, such as patterns for the order Ericales or the order Rosales. We are very sorry for this unclear expression, and we have revised it (Please see line 60).  

8. 65: what is the ‘other pattern’ you refer to here?

 Response: Thank you for pointing this out. Here the ‘other pattern’ refer to ‘the order Ericales’. We are very sorry for this unclear expression, and we have changed it to “the order Ericales” (Please see line 61). 

9. 67: with its members distributed

 Response: Thank you for pointing this out. We have revised it as suggested (Please see line3 63-64). 

10. 77: This study will test: (1) ….

Response: Thank you for pointing this out. We have revised it as suggested (Please see lines 74-77). 

11. 90: is there new data in this paper, or is it all from a pre-existing dataset?

Response: Thanks for your question. There is no new data in this paper, it is all from the DLP data set (Peppe et al., 2011).

The DLP data set contains the physiognomic scores of all species in the calibration sites. We calculated the physiognomic scores of the order Ericales. In the DLP data set, we first selected the sites with at least 2 species of the order Ericales. For the order Ericales, species means were first calculated, then site means of the order Ericales were derived from the species means.

Peppe, D.J.; Royer, D.L.; Cariglino, B.; Oliver, S.Y.; Newman, S.; Leight, E.; Enikolopov, G.;  Fernandez-Burgos, M.; Herrera, F.; Adams, J.M.; Correa, E.; Currano, E.D.; Erickson, J.M.; Hinojosa, L.F.; Hoganson, J.W.; Iglesias, A.; Jaramillo, C.A.; Johnson, K.R.; Jordan, G.J.; Kraft, N.J.; Lovelock, E.C.; Lusk, C.H.; Niinemets, U.; Penuelas, J.; Rapson, G.; Wing, S.L.; Wright, I.J. Sensitivity of leaf size and shape to climate: global patterns and paleoclimatic applications. New Phytol. 2011, 190, 724–739.

12. 91: what characters? I would like to know exactly what features of the leaves are What are the 27 variables??

Response: Thank you for pointing this out. We have changed “ leaf characters” to “leaf physiognomic characters” (Please see line 84).

Physiognomic characters of leaves include percent of untoothed species, petiole area, blade area, perimeter, major length, internal perimeter, tooth area , number of primary teeth and number of secondary teeth. (Please see the supplementary data, Table S2)

The 27 leaf physiognomic variables are constructed by leaf physiognomic characters, they are E-Percent untoothed, E-Petiole area, E-Blade area , E-Leaf area, E-ln(leaf area), E-Perimeter, E-Major length, E-Internal perimeter, E-Tooth area, E-#primary teeth, E-ShapFact,  E-#Teeth, E-Comp, E-ln(Comp), E-Feret's diameter, E-FDR, E-ln(FDR), E-Peri/Area, E-ln(Peri/Area), E-PeriRatio, E-ln(PeriRatio), E-#Teeth/Peri, E-#Teeth/IntPeri, E-TA/BA, E-TA/Peri, E-TA/IntPeri and E-#Teeth/BA (Please also see supplementary data, Table S1)

13. 109: all other abbreviations are defined here, but not MAP. MAT, MART, and MAP were all defined in first paragraph. GSP is the only one defined here for the first    I recommend defining all abbreviations once in the first paragraph and then not defining again to avoid redundancy.

 Response: Thank you for pointing this out. We have revised it as suggested (Please see lines 30-31, 43)

14. 111: extra spaces on this line

 Response: Thank you for pointing this out. We have revised it as suggested (Please see line 102).

15. 122: models {22    there is a space missing

Response: Thank you for pointing this out. We have revised it as suggested (Please see line 112).

16. 133: missing space

Response:Thank you for pointing this out. We have revised it as suggested (Please see line 121).

17. 136: should p be italicized?

 Response: Thank you for pointing this out. We have revised it as suggested (Please see line 123). 

18. 138: space missing before reference; I will not point out this in following parts of the manuscript. The authors need to make sure they are consistently adding a space before the references.

 Response: Thank you for pointing this out. We have checked our manuscript and revised it (Please see line 124). 

19. 141: should r be italicized?

  Response: Thank you for pointing this out. It should be italicized. We have checked our manuscript and revised it as suggested (Please see lines 126,127, 154,155,160-161, 175-199). 

20. 153: R as in the R statisitcal package? Need to explain this better and say what version you used

  Response: Thank you for pointing this out. We have revised them as suggested (Please see line 137). 

21. 154: MASS has yet to be defined as an abbreviation

 Response: Thank you for pointing this out. We have revised it (Please see line 133). 

22. 165: what is RMSE? Not defined

  Response: Thank you for pointing this out. We have defined it on line 157 (section 2.4.3). 

23. 172: sub-data

  Response: Thank you for pointing this out. We have revised it (Please see line 152). 

24. 182-187: various short paragraphs that need to be combined into a larger paragraph. Try not to start a paragraph with a lowercase r-squared.

   Response: Thank you for pointing this out. We have revised it (Please see lines 160-166). 

25. Line 202: what is the threshold used for a significant positive correlation? That should be defined in the methods. These r-squared values seem low to me.

Response: Thank you for pointing this out. We have revised it as suggested (Please see line 109). 

The statistically significant of r-squared value is measured by P-value. Generally, when the P-value is no more than 0.05, the statistical correlation is considered to be significant (Royer et al., 2008).

In the similar study of Peppe et al. (2011), percent of untoothed species has the highest r-squared value with mean annual temperature (MAT) (r² = 0.58, P < 0.001), r-squared values of other leaf physiognomic variables with MAT are concentrated in 0.2~0.4 (P < 0.05; In fact, the second highest r² is 0.37). There are similar results in the study of Royer et al. (2008).

In the study of Peppe et al. (2011), only several physiognomic variables correlated significantly with mean annual precipitation (natural logarithmic transformed), the highest r² is 0.24, other r² are between 0.05 and 0.2 (P < 0.05).

The normal range of r² of physiognomic variables and growing season precipitation (GSP) is 0.05 to 0.16 (P < 0.05) (Peppe et al. 2011).

The normal range of r² of physiognomic variables and mean annual range in temperature (MART) is 0.1 to 0.3 (P < 0.05) (Peppe et al. 2011). 

26. Line 207: not sure what is meant by woody dicotyledonous here. Is this in reference to one of the models?

 Response: Thank you for pointing this out. We are very sorry for this unclear expression. We have changed this sentence by “Among these variables, E-ln(leaf area) has the strongest correlation with MAT, while among the leaf physiognomic variables of woody dicotyledons species, percent of untoothed species has the strongest correlation with MAT [8]” (Please see line 177). 

27. 222: extra colon to delete

  Response: Thank you for pointing this out. We have revised it as suggested (Please see line 189). 

28. 226: Figure. 5     delete ‘

 Response: Thank you for pointing this out. We have revised it as suggested (Please see line 193). 

29. 272: Ericales

 Response: Thank you for pointing this out. We have revised it as suggested (Please see line 232). 

30. 290 two classes models? Two class-models?

   Response: Thank you for pointing this out. We have revised it as suggested (Please see line 246, 286). 

31. 298: don’t use word proved. Don’t have a single-sentence paragraph

  Response: Thank you for pointing this out. We have revised it as suggested (Please see lines 253-259, 261). 

32. 302-303: modern

 Response: Thank you for pointing this out. We have revised it as suggested (Please see line 256). 

33. 319: probably? Awkward wording

 Response: Thank you for pointing this out. We have modified the expression by “Our WDS-E MAT liner 269 model has a similar prediction precision with the artificial neural network model built based on CLAMPE data of 376 sites” (Please see line 268-269).

34. 331: extra period

Response: Thank you for pointing this out. We have deleted the extra period (Please see line 278). 

35. 339: for

Response: Thank you for pointing this out. We have deleted the extra “for” (Please see line 283).

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

Title: Contribution of the order Ericales to improving paleoclimate reconstructions

Dear authors,

 The manuscript is quite good and very interesting and can be useful for many researchers.

The very idea of the research is very innovative and can serve to better understand and reconstruct the paleoclimate. The author's critical review of the number of locations and further verification through future research is especially important.

I am deeply convinced that this research will encourage other researchers to address this issue.

Also, I think this manuscript will have very good scientific soundness

Because of all the above, I am pleased to suggest the publication of your manuscript.

Author Response

Mar 20, 2022

Dear reviewer,

Thank you very much for your positive comments concerning our manuscript entitled "Contribution of the order Ericales to improving paleoclimate reconstructions".

Your affirmation and encouragement strengthened our courage and determination to continue this research.

Thank you.

Best regards.

Round 2

Reviewer 1 Report

I recognize that the authors improved appropriateness with changes to the text. There are still a few very minor English-language edits that need to be made during copy-editing.