Novel Yield Model of Pinus patula Schltdl. & Cham. Growth near the Ecological Limit in Northwestern Peruvian Andes

Round 1

Reviewer 1 Report

Comments to the text are in the attached file.

Comments for author File: Comments.pdf

Author Response

We would like to thank the reviewer for their comments and suggestions that undoubtedly improved the quality of the manuscript. We respond point by point to your comments in the attached document.

Author Response File: Author Response.docx

Reviewer 2 Report

The evaluation of tree growth and its modeling approach is a very important issue in relation to the proper forest management decisions. The subject of this research paper falls within the scope of the journal of “Forestry”. It is a nice work. Below I am giving my comments and suggestions.

 

Introduction

 Lines 57-58: “the Granja Porcón project is one of the most successful forest plantation model in the region” What exactly do you mean by this? Please explain.

 

Lines 87-88: “In the present study we analyze the annual growth of P. patula near ecological limit in Northwestern Peruvian Andes through dendrochronological techniques.” Which are these techniques? Please include the necessary information.

 

Materials and Methods

 Lines 130-132: “Five percent of the total surface in each stand was inventoried. Ten and nine experimental plots (500 m² plot^-1) were randomly allocated for Cushuro and Enterador area, respectively (Figure 1A).” Here, the authors have to explain the sampling strategy they chose to use. Why 5%? Why ten and nine experimental plots? Are these choices depended on the variability observed?  Is the plot size adequate? Please explain using arguments and relative references.

 

Line 132: “The characteristics of the sampled stands are summarized in Table 1.”. A paragraph is needed with the description of the ground-truth measurements are taken in the field.

 

Table 2: [10-20> Do you mean [10-20): close and open interval?

 

Table 2: I assume that the first column of volume is referred to measured trees. It is not clear what the second column of volume refers to.

 

Table 2: You have to explain how the volumes of Table 2 were calculated. Are estimations derived from an equation or they derived from observed sectional data measured on the tree stem?

 

Lines 137-140: “Thirty-five P. patula trees classified as dominant and representative of each stand (based on the mean wood volume from the inventory) were selected; the number of P. patula trees was established with a 95% confidence level (α = 1.96) and with an acceptable limit of sampling error of 10% (e = 0.1)” You have calculated confident intervals. Under which distribution. Are your volume data normally distributed? Explanations are needed.

 

 

Line 148: “The number of sample trees (n) was calculated by equation” A reference is needed. Furthermore, you have to explain if this formula is used for proportion determination or for the mean population estimation, etc. Which is your dominant research variable that your sampling strategy based on?

 

Line 149: Is this equation 1? Then the equation of line 158 must be equation 2, etc

 

Lines 154-155: “The annual tree-rings of cores were synchronized and visually cross-dated to confirm the stand age”. How? You have to describe this, and you have to insert relative references.

 

Line 166: “Stand analysis”. Relevant references have to be added throughout, to support the methodology used.

 

Lines 263-264: “The correlation between the predictions was 0.95 (r²)”. Do you mean r? (r² is the coef. of determination)

 

Figure A1: You have to follow the same notation. There is “observed volume”, “estimated volume” and “volume”. Is the last refeed to observed or estimated volume

 

Figures A2 and A3: The heteroskedasticity is obvious. Have you thought of any transformation of the dependent variable or to use weighted regression? To my opinion, a supportive paragraph is necessary to be inserted.

 

Lines 268-276: If I have understood correctly, you stated that Chapman nonlinear (Eq. 2) fit well the cumulative tree DBH and volume, with RMSE values 17% and 18% of the mean dbh and 39% and 44% of the mean volume. Having in mind the above errors, to my opinion, the nonlinear model you have used failed to adequately be adapted to the available data unless it cannot be otherwise. Please, explain. Arguments are needed to support the methodology used. For example, why have you used the Chapman nonlinear model to fit diameter and wood volume cumulative growth, that provided rather high errors? Or these errors are not considered as high. Please, explain.

 

Conclusions

Lines 490-495: These conclusions are already known in the scientific community. You have to highlight your novel findings. Generally speaking, any novelty of your work need to be highlighted.

Author Response

We would like to thank the reviewer for their comments and suggestions that undoubtedly improved the quality of the manuscript. We respond point by point to your comments in the attached document.

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

I do not have any further comments and suggestions

Author Response

We would like to thank the reviewer 2 for their comments and suggestions that undoubtedly improved the quality of the manuscript. Below we respond point by point to his comments.