Effects of Competition on the Vertical Distribution of Foliage Biomass within the Crowns of Planted Korean Pine Trees in Northeast China
Round 1
Reviewer 1 Report (Previous Reviewer 1)
The track changed did not follow in the discussion and conclusion section. The authors should pay more attention when submitting their reviewed files.
Other specific comments:
Their is two figures labeled "Figure 1"
The added text to the abstract seemed redundant. Sentence beginning at line 21 seems to repeat the same information then the sentence that begin at line 23. The added text to the abstract repeat information that was already mentioned at line 25. Please revise carefully the abstract in order to make it clear and remove the redundant parts.
The new figure 1 could be a good addition however the crown characteristics do not seem to always fit with the description in the text. For example LR1 should be labeled L, and OCR presented in the figure is not describe in the text. Please make sure that the information from the figure is coherent with the text of the manuscript.
The description of LR1 in the text is not clear. an illustration of this variable could help to understand what does the authors means by "distance from the leader to the midpoint of the annual shoot".
Author Response
Comments from reviewer 1
The track changed did not follow in the discussion and conclusion section. The authors should pay more attention when submitting their reviewed files.
Response: Thank you for this comment. We have paid more attentions when resubmitted our revised manuscript.
Specific comments:
Comment 1: Their is two figures labeled "Figure 1".
Responses: OK. We have revised it and all the related figure number has been revised.
Comment 2: The added text to the abstract seemed redundant. Sentence beginning at line 21 seems to repeat the same information then the sentence that begin at line 23. The added text to the abstract repeat information that was already mentioned at line 25. Please revise carefully the abstract in order to make it clear and remove the redundant parts.
Responses: Thank you for this comment. We have revised carefully in the abstract and all the redundant information has been removed. We also added one simple description related to the relationship between the peak of the foliage biomass distribution and the age.
Comment 3: The new figure 1 could be a good addition however the crown characteristics do not seem to always fit with the description in the text. For example LR1 should be labeled L, and OCR presented in the figure is not describe in the text. Please make sure that the information from the figure is coherent with the text of the manuscript.
Responses: OK. We have replaced the LR1 with L. Because OCR was not used in the research, therefore we have deleted this label in the revised figure.
Comment 4: The description of LR1 in the text is not clear. an illustration of this variable could help to understand what does the authors means by "distance from the leader to the midpoint of the annual shoot".
Responses: OK. We have added a simple illustration for the defination of LR1 in the 2.4 section below equation 2.
Reviewer 2 Report (Previous Reviewer 2)
The authors have carefully revised the manuscript. I believe it could be accepted for publication.
Author Response
Dear reviewer,
Thank you very much for your encouragement to our work. Best wishes for you.
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
General comment
The manuscript reports a study made on Korean pine to model the foliage biomass and its vertical distribution along the stem. A total of 51 trees were destructively sampled and foliage biomass of a subsample of branches was measured. Alometric relationships to estimate foliage biomass at the branch level was parameterized with branch tree and stand level covariables. The same process was used to model the annual shoot foliage density based on the location of the annual shoot along the tree crown.
The subject of the study is relevant and foliage biomass estimation and craterisation could be important input for process-based models. When accounting for the amount of time that is necessary to accumulate data on foliage biomass, the number of trees that were sampled is impressive, even if more sampling at the second site the Beisanjia forest form would have be desirable. The statistical analysis seems globally correct; however I have some doubts about the method used to estimate foliage biomass at the branch level by using the ration of fresh weight of foliage over the total weight of a median branch (see my comment at line 182).
My main comment is about the writing of the manuscript. I believe the muscrit would benefit from a thorough review to better explain the methods and results. The main results presented in Figures 2 to 5 were difficult to understand because of the lack of explanation. In addition, some of the authors' interpretations of the results seem to me to be erroneous (see my specific comments).
Specific comments
Line 23 remove the abbreviation for FDRs it not used elsewhere in the abstract
Lines 31-32 replace “machinery” by “process”
Lines 37-38 replace “is the main 37 component for photosynthesis,” by “directly affect photosynthesis” or “is the main driver of photosynthesis”.
Lines 114-117 Please reformulate to clearly mention that 5 stands include 3 sample plots and one last stand include 1 plot. If I understood well…
Line 119 I count 17 plots from Table 1
Table 1 I suggest adding the number of trees selected in Table 1
Table 2 The maximum tree age exceed the maximum stand age in Table 1, please correct if it is a mistake otherwise, please provide an explanations
L182 I am not sure that this method is correct you assume that the ratio of foliage over total branch weight is the same for all the branches from the same section. This ratio could change a lot with the diameter and the length of the branch. To my opinion it would have been better to only used the sample branches (3 per trees) in the foliage biomass model calibration and predict the foliage biomass of other branches with the use of the equation.
L189 Consider replacing « The foliage biomass of the annual shoot” by “The foliage biomass of the branches located on a same annual shoot”
L199 et 201 This is unclear to me how you did the age of the branches. Please provide explanations.
L200 et L202 Please define what is the branch position in the crown
Equations 1 and 2. Please add the random effect as well as your vector of fixed effect in the equations.
Equation 3 If I understand, BD is the branch diameter, I don’t understand how branch diameter can be used to model the relative annual shoot foliage density. These variables belong to two different scales, the branch level and the annual shoot level. Moreover, the power function is monotonic and cannot account for a maximum value inside the crow
Line 225 LR should be divided by some values to be “relative” please mention it
Line 229 Please add “s” to neighbor tree.
Lines 258-268 Most of this text should be moved to the Method section
Equation 8 Please explain how you come to mix different forms of equations by including exponential coefficient with the power part of the function. This form of equation is a bit strange, and the authors should check the behaviour of the predicted values and report that they have check that the equation do not produce aberrant values.
Line 263 and Equation 8 Should write BD instead of DB
Line 273 Did a2 and a5 are random coefficient or does random coefficient were added to the fixed parameters. Please rewrite Equation 8 to clarify this.
Table 4 and Table 5 Equation number are mixed, should Equations 8 and 9 not 7 and 8
Figure 1 Please explain how you obtained the plotted values. I am guessing that you used model 8 and applied it to each living branch than summed the foliage biomass by section and averaged the values for all the trees with the same age. You should provide more details otherwise; the results are difficult to understand. Also, I do not see other reference to the relative distance to branch base (x axis), please define what is this variable.
Figure 2 and Figure 4 Please write CI1 with the 1 placed in indices otherwise we could get confused with CLI variable
Lines 280 to 281 and 315 to 316. Please explain why based on figures 1,2,3,4 you can affirm that the models show good performance. You could mention this if the predictions were plotted against observed data, but this is not the case here.
Equation 9 I cannot figure out how branch diameter (BD) can figure as a predictor of foliage density ratio at the annual shoot level. Do you mean cumulative branch diameter, mean branch diameter? If so, you need to change the name of the variable.
Line 373-374 I do not agree with the authors the negative coefficient indicate that all other variables kept constant, trees with longer crowns would have lower amount of foliage for a branch of the same size. However, trees with smaller crown ration for a same height would have foliage concentrated higher in their crown simply because e their crown are shorter.
Line 383 I don’t se a change in the distribution of foliage with parameters a7 and b3 only less foliage for trees with higher competition.
Line 385 to 387 I disagree with the authors, the respond variable of the two equation is on a different scale so you cannot compare the effect of the coefficient simply by comparing their absolute value.
Lines 397-399 The authors reported previously that the power function for foliage density per annual shoot fitted poorly and the results were not reported. Instead, the authors used a beta function. Please correct the sentenc
Author Response
Please see the attachment.
Author Response File: 
Author Response.docx
Reviewer 2 Report
The article tries to model foliage biomass at branch and annual shoot levels using destructively sampled Korean pine. Indeed, this is not an easy task, especially for the parts of field experiments. However, the work presents some seriously limitations.
1. The experimental design seems to unclear. First, there is not sufficient information to explain why the forest stand in Beisanjia forest farm is selected. Since it only one sample plot and the three sampled trees are all dominant, which are not consistent with the other plots in Dabiangou forest farm. In addition, the two farms are long distance separation.
Second, the sampling method seems a bit confusing. In line 137-139, it mentions 51 sample trees were selected in sample plots and measured. But in line 140-141, “all the sample trees were chosen outside the plots”. So, are the neighbor trees in line 143 in or out of the sample plots?
2. It seems that the key processes of modeling are not well described. For example, in the model of the branch level (line 206), β0i and β1i are two crucial parameters that must be evaluated. However, there are no detailed analysis of β0i and β1i in the results, such as model forms and coefficients of parameter. Besides, the prediction model in the results (line 270) is not consistent with that in Materials and Methods (line 206). The same problem exists in the model of the annual shoot level.
3. The equation (4)-(7) are cited from Sun et al. 2022 and Ledermann 2011 (line 231). However, they are not list in references. It hardly to estimate whether it works.
Other suggestions as follows:
(1) List supported literature for calculation method in lines 185-189.
(2) The discussion is not in-depth enough to highlight the importance and novelty of this study, especially for the competition. How can it be further applied? Please highlight the limitations and strengths.
(3) The format of the references is not uniform.
Author Response
Please see the attachment.
Author Response File: Author Response.docx
Round 2
Reviewer 1 Report
The authors have responded adequately to most of my previous comments. They have improved their methodology and corrected most of the problems with the paper. However, I think that discussion and conclusion should be improved to present a better and more elaborated interpretation of the results.
Specific comments (lines number refer to the clear version of the manuscript)
Figure 1 to 4. I am a bit surprised that the figures are identical to the previous version of the paper even if the method for the calculation of the foliage biomass changed between the two version (see comment 8 in the Authors reply file). Can you provide an explanation for this?
Figure 3 and 4 units should be Kg/m/m
Line 370 please provide more explanations
Lines 384-385 can you provide an explanation for this?
Lines 386-394 I suggest that that you discuss more deeply these results, you conclude that pines with some height and longer crown had less foliage at the branch level but more foliage at the annual shoot level. What could be the reasons for these results?
Lines 395-405 You mentioned that you observed an effect of CI1 on the foliage biomass distribution please mention what is this effect and what are the implications for the smaller versus the larger trees.
Lines 409-414 This sentence is ambiguous please develop your idea. What can be the impact of silvicultural systems on foliage biomass distribution and then on tree growth or on other tree or stand characteristics.
Line 429 With the age of individual trees instead of with the growth?
I also suggest that you revise your conclusion to include the overall value of your study in relation to what has already been made on the subject. Also consider mention some future perspectives for the work that you conduct on Korean pines.
Author Response
Effect of competition on the vertical distribution of foliage biomass within the crown of planted Korean pine trees in northeast China
（forests-2030206）
Responses to the comments from reviewer 1
Dear reviewer,
Thank you very much for the encouragement to our manuscript. Following your comments, we have revised carefully and given detailed responses to each comment as follows. We hope that all the revisions could meet your concerns.
General comments
The authors have responded adequately to most of my previous comments. They have improved their methodology and corrected most of the problems with the paper. However, I think that discussion and conclusion should be improved to present a better and more elaborated interpretation of the results.
Response: Thank you very much for your encouragement to our work. Following your comments, we have revised carefully and the discussion and conclusion have been improved. All the revisions were marked with red color. The detailed revisions were showed as follows.
Specific comments
Comment 1: Figure 1 to 4. I am a bit surprised that the figures are identical to the previous version of the paper even if the method for the calculation of the foliage biomass changed between the two version (see comment 8 in the Authors reply file). Can you provide an explanation for this?
Response: We are so sorry for this mistake. Actually, all the figures have changed and there were some mistakes when replacing with the revised figures in the former version. We have replaced with the right figures in the revised manuscript showed as Figures 1 to 4. The revised figures have the similar trends to the former version.
Comment 2: Figure 3 and 4 units should be Kg/m/m.
Response: OK. We have revised it as showed in Figure 3 and Figure 4.
Comment 3: Line 370 please provide more explanations
Response: OK. We have added more explanations following your comment and the new reference has been listed as showed Lines 377-380.
Comment 4: Lines 384-385 can you provide an explanation for this?
Response: OK. Following your comment, we have added an explanation as showed Lines 396-398.
Comment 5: Lines 386-394 I suggest that that you discuss more deeply these results, you conclude that pines with some height and longer crown had less foliage at the branch level but more foliage at the annual shoot level. What could be the reasons for these results?
Response: Thank you very much for this comment. We thought your comment carefully. We thought that this sentence is not right based on the parameter estimates and we are sorry for this mistake. We have revised it and added some explanations as showed Lines 403-404.
Comment 6: Lines 395-405 You mentioned that you observed an effect of CI1 on the foliage biomass distribution please mention what is this effect and what are the implications for the smaller versus the larger trees.
Response: OK. We have given the responses following your comment as showed Lines 409-413.
Comment 7: Lines 409-414 This sentence is ambiguous please develop your idea. What can be the impact of silvicultural systems on foliage biomass distribution and then on tree growth or on other tree or stand characteristics.
Response: OK, we have revised it carefully based on our next step of the research as showed Lines 428-435.
Comment 8: Line 429 With the age of individual trees instead of with the growth?
Response: OK. We agree with you and we have revised it as showed Line 448.
Comment 9: I also suggest that you revise your conclusion to include the overall value of your study in relation to what has already been made on the subject. Also consider mention some future perspectives for the work that you conduct on Korean pines.
Response: Thank you very much for this comment. We have added the overall value of our study and some future perspectives for our work as showed Lines 439-441 and Lines 451-453.
Author Response File: Author Response.docx
Reviewer 2 Report
The authors have made some changes to the article. Unfortunately, I can’t find the revision base on the line number mentioned in the response. It is better to check the materials carefully before uploading. In addition, the key information or explanation in the authors’ reply should be added in the MS. By the way, the compositions of β0i and β1i are still not clearly stated.
Author Response
Effect of competition on the vertical distribution of foliage biomass within the crown of planted Korean pine trees in northeast China
（forests-2030206）
Responses to the comments from reviewer 2
Dear reviewer,
Thank you very much for your comments. We have carefully checked the line number mentioned in the response letter and we are sorry for the confusion caused to you. In addition, the key information or the explanation have been added in the manuscript following your comment. Therefore, the responses to your former comments and this time were all listed as below. To improve the language of our manuscript, it has been edited by MDPI to improve the language quality. The certificate has been uploaded. We hope that the revisions could meet your concerns.
Comments from reviewer 2
General comments
The authors have made some changes to the article. Unfortunately, I can’t find the revision base on the line number mentioned in the response. It is better to check the materials carefully before uploading. In addition, the key information or explanation in the authors’ reply should be added in the MS. By the way, the compositions of β0i and β1i are still not clearly stated.
Response: We are so sorry for the confusion for you. Following your comment, the key information or explanation has been added in the MS as showed Lines 121-123, 143-145, and 147-148 and the parameter β0i and β1i have been clearly documented as showed Lines 220-223 and Lines 273-277 in the revised manuscript.
We have checked the line number and all the responses to your former comments were listed below.
General comments
The article tries to model foliage biomass at branch and annual shoot levels using destructively sampled Korean pine. Indeed, this is not an easy task, especially for the parts of field experiments. However, the work presents some seriously limitations.
Comment 1: The experimental design seems to unclear. First, there is not sufficient information to explain why the forest stand in Beisanjia forest farm is selected. Since it only one sample plot and the three sampled trees are all dominant, which are not consistent with the other plots in Dabiangou forest farm. In addition, the two farms are long distance separation.
Second, the sampling method seems a bit confusing. In line 137-139, it mentions 51 sample trees were selected in sample plots and measured. But in line 140-141, “all the sample trees were chosen outside the plots”. So, are the neighbor trees in line 143 in or out of the sample plots?
Response: For your first comment, we would like to give the following explanation. In eastern area of Liaoning province, the Korean pine is widely planted in Dabiangou forest farm and Beisanjia forest farm. The site quality and the local topography are all the same. Korean pine plantation with the age lower than 40 years was defined as the young-aged forest, and the plantation with age between 40-60 years was defined as the middle-aged forest. We intend to expand the sample size in the middle-aged forest. Therefore, we choose Beisanjia forest farm as another sample site. As for the three dominant trees selected from Beisanjia forest farm, we intend to expand the sample size. The intermediate tree and suppressed tree were difficult to selected because the stem taper was difficult to control. Therefore, we selected three dominant trees. We have conducted the primary analysis, the three sample trees strengthen the model fitting. In the next step, we will further enlarge the sample size to understand the foliage biomass distribution under three tree statuses. The key information has been added in the revised manuscript as showed Lines 121-123, Lines 143-145.
For your second comment, we would like to give the following explanation. We develop the sample plot first and we plan to remeasure the trees in the future. Therefore, all the sample trees selected based on the sample plots were selected outside the plot where the forest condition is similar to the sample plot to ensure the intact for the sample plot. Therefore, the neighbor trees are also out of the sample plots. The key information has been added in the revised manuscript as showed Lines 147-148.
Comment 2: It seems that the key processes of modeling are not well described. For example, in the model of the branch level (line 206), β0i and β1i are two crucial parameters that must be evaluated. However, there are no detailed analysis of β0i and β1i in the results, such as model forms and coefficients of parameter. Besides, the prediction model in the results (line 270) is not consistent with that in Materials and Methods (line 206). The same problem exists in the model of the annual shoot level.
Response: Thank you very much for this comment. Following your comment, we have added the parameter estimation information for β0i and β1i and the model performance showed as Lines 217-223, and Lines 273-277. Because we have given detailed description in the method approach, we only gave concise information and analysis for the two parameters including p values of the two parameters. Following the study of Goudie et al. (2016), we used the power model with the branch diameter as the primary explanatory variable.
Reference
Goudie, G.W., Parish, R., Antos, J.A. 2016. Foliage biomass and specific leaf area equations at the branch, annual shoot and whole-tree levels for lodgepole pine and white spruce in British Columbia. For. Ecol. Manage. 361: 286–297.
Comment 3: The equation (4)-(7) are cited from Sun et al. 2022 and Ledermann 2011 (line 231). However, they are not list in references. It hardly to estimate whether it works.
Response: Thank for this comment. We have added the two references in the reference list showed as Lines 544-547.
Specific comments
Comment 1: List supported literature for calculation method in lines 185-189.
Response: Thank you very much for your comment. We think it carefully and we found that the assumption that the ratio of foliage over total branch weight is the same is not correct because the ratio could change a lot with the diameter and the length of the branch. Therefore, we used all the sample branches (3 per tree) in the foliage biomass to develop the foliage biomass model. To use the full information for the sample branch, the leave-one-out approach was used to validate the model performance. The developed foliage model was used to predict the foliage biomass for the other branches. The detailed revisions showed as follows:
(1) We have deleted the description of the calculation method for the other branch foliage showed as Lines 190-192.
(2) In the section 2.4, we have documented that the foliage biomass for the other branches was predicted using the developed foliage biomass model based on the measured foliage biomass for the sample branches. The revisions were showed as Line 201-202.
Comment 2: The discussion is not in-depth enough to highlight the importance and novelty of this study, especially for the competition. How can it be further applied? Please highlight the limitations and strengths.
Response: Thank you very much for your comment. We appreciate this advice and we have strengthened the Discussion section in the revised manuscript to highlight the importance and limitation of our study. We hope that the revisions could meet your concerns. The revisions were showed as Lines 421-435.
Comment 3: The format of the references is not uniform.
Response: The format of the references has been revised.
Author Response File: Author Response.docx
