An Algorithm for Determining Pith Position Based on Crown Width Size
, Yingshan Jin 4,*, Liming Cai 2,3,5, Zhuofan Li 2,3,6, Fang Li 4 and Fang Liang 4Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsEstimating the pith position in standing trees is challenging. Obtaining the direction of a diameter line through the tree pith is the basis of effective sampling by a micro-drill resistance instrument. In the manuscript submitted by Jianfeng Yao et al., an attempts to estimate the position of the tree pith using crown width. The studies were conducted on two species, Pinus tabulaeformis and Platycladus orientalis.
The manuscript fits well with the journal´s aim and scope. It is acceptably written and the methods appear to be well applied. The discussion is enough although somehow descriptive. The main drawback is that there is no clear initial hypothesis, something needed in the scientific method. Authors should fix the issue in future versions.
In this review, I offer a few suggestions as to where certain points can be elaborated upon or revised in the manuscript.
Detailed comments:
1. Please adapt the abstract to the requirements of the Forests journal ((approximately 200 words maximum; Forests | Instructions for Authors
2. Lines 91-91: Please complete: Is: "120 meters" should be: 120 meters a.s.l."
3. Line 94; 98: I conclude that the age of Pinus tabulaeformis is 54 years and Platycladus orientalis is 34 years. Please consider adding age information for the species studied.
4. Lines 109-110: Please describe the method of measuring the crown width. What measuring device was used?
5. Lines 115: Table 1:Please check the correctness of the data in Table 1. If “CW” means crown width, then the unit is probably meters. The table says “CW/cm”, it should be “CW/m”. The values ​​in the minimum and maximum columns are also incorrect.
Please add an explanation of the abbreviation "CW" under the Table 1. Tables must be auto-explicative.
6. Figure 3. Please improve the quality of the figure 3. It is illegible in this shape.
7. Reference Lines 323-405: References not prepared in accordance with the requirements journal Forests. Forests | Instructions for Authors (mdpi.com)
Author 1, A.B.; Author 2, C.D. Title of the article. Abbreviated Journal Name Year, Volume, page range.
Author Response
Comments 1 :Please adapt the abstract to the requirements of the Forests journal ((approximately 200 words maximum; Forests | Instructions for Authors
Response 1: Thank you very much for your detailed review of my manuscript. We have revised the abstract and have limited the word count of the abstract to 200 words.
Comments 2: Lines 91-91: Please complete: Is: "120 meters" should be: 120 meters a.s.l."
Response 2: Thank you for your valuable feedback! The "120 meters" has been changed to: "120 meters a.s.l.". We have carefully checked the entire text to ensure that similar mistakes will not appear again.
Comments 3: Line 94; 98: I conclude that the age of Pinus tabulaeformis is 54 years and Platycladus orientalis is 34 years. Please consider adding age information for the species studied.
Response 3: Thank you for your further comment. We have added age information after the tree species that appear in the article, as you would expect. “The age of Pinus tabuliformis is 56 years.” and “The age of Platycladus orientalis is 37 years.”
Comments 4: Lines 109-110: Please describe the method of measuring the crown width. What measuring device was used?
Response 4: Thank you for your feedback! We have added a method for measuring crown width in the Methods section, as well as the equipment required for the measurement process.
Comments 5: Lines 115: Table 1:Please check the correctness of the data in Table 1. If “CW” means crown width, then the unit is probably meters. The table says “CW/cm”, it should be “CW/m”. The values ​​in the minimum and maximum columns are also incorrect.
Response 5: Thank you for your insightful suggestion. We have carefully checked the data in Table 1. CW here stands for crown width, and its unit should be meter. I am very sorry that my carelessness has caused you some trouble. We have carefully checked the data in other tables and figures to ensure that there will be no similar mistakes.
Comments 6: Please add an explanation of the abbreviation "CW" under the Table 1. Tables must be auto-explicative.
Response 6: Thank you for your insightful suggestions. We have added the explanation of the variable name CW in Table 1 below, and explained the meanings of other variable names.
Comments 7: Figure 3. Please improve the quality of the figure 3. It is illegible in this shape.
Response 7: Thank you for your feedback! Figure 3 in the article has been replaced with a clearer image and the text in the image has been enhanced to ensure clarity and readability. We also thoroughly checked the clarity and readability of all charts to ensure that their content can intuitively convey research information. If there are any other suggestions or areas that need further improvement, please feel free to point them out!
Comments 8: Reference Lines 323-405: References not prepared in accordance with the requirements journal Forests. Forests | Instructions for Authors (mdpi.com)
Author 1, A.B.; Author 2, C.D. Title of the article. Abbreviated Journal Name Year, Volume, page range.
Response 8: Thank you for pointing out the shortcomings of the article. We have modified the references appearing in the article according to the requirements of journal Forests for references. The references in the article have been modified to the correct format: “Author 1, A.B.; Author 2, C.D. Title of the article. Abbreviated Journal Name Year, Volume, page range”.
Reviewer 2 Report
Comments and Suggestions for AuthorsAn algorithm for determining the pith position based on crown width size
This paper proposes an algorithm to estimate the pith position from measurements made on a standing tree. It assesses various statistical regression models for predicting pith position from crown and then radius ratios. The developed model was then compared to conventional geometric centre method. It was revealed by the experiments on 2 species of trees, each consisting of 60 samples that the proposed crown with method gave higher predicting accuracy by about 3 percents. The paper is well written, and the development of the method was scientifically valid. While the model is straightforward with minimal computations involved, the experimental results reported herein confirmed that it was effective and reasonable robust. However, the paper could benefit from the following revisions before it can be accepted for publication in Forests journal.
1. The authors surveyed various imaging techniques and criticized, while being accurate, they involved costly equipment. It would then be reasonable to compare the accuracy of the proposed method with theirs, so that the readers could imply the cost per accuracy balances. Only meta-analysis and discussion would suffice. Please provide comparative evidence in the result section.
2. Likewise, it was stated that other intrinsic parameters of the trees also play important roles in determining pith position (Lines 68-82). However, such data were not considered in this paper. Please provide some factor analyses or relevant discussion as appropriate.
3. Measurements expressed in Eq. (1) – (8) could be accompanied by the corresponding diagrams (overlay on the tree or its cut image) so that the reader can visualize and grasp the dimensions and actual appearance of these variables (Similar to what drawn in Fig. 1).
4. While it was indicated that the linear model outperformed the others when predicting radius ratio from crown width ratio, the differences were only marginal. Besides, the R^2 was in fact quite low (about 0.4). From Fig. 3, the errors were mainly presented when crown width ratio were deviate from population mean. Please discuss whether how this would affect the subsequent pith prediction.
5. While the crown width ratio to radius ratio function was derived and clearly expressed. That for predicting pith position from these variables was missing. Please explain.
6. The titles of vertical axes in Fig. 4(a) and (b) seems wrong. Please recheck. Besides they do not have any unit. Please provide for both vertical and horizontal axes. In fact, please also explain how they were calculated.
7. On a similar note, please elaborate how “curve reaching its peak earlier” indicates better performance? The same comment applies to other contribution statements made in this study.
Comments on the Quality of English Language- Due to language inaccuracies, various sentences are unnecessarily too complex and hence read confusing, e.g., “The crown ratio of the crown width in each direction to the sum of crown width in that direction and the opposite direction, and radius ratio of the radius of each direction to the diameter of that direction were calculated.” Please revising the writing style throughout.
- Other language errors were also found in the manuscript. Extensive editorial polishing is therefore mandatory.
Author Response
Comments 1: The authors surveyed various imaging techniques and criticized, while being accurate, they involved costly equipment. It would then be reasonable to compare the accuracy of the proposed method with theirs, so that the readers could imply the cost per accuracy balances. Only meta-analysis and discussion would suffice. Please provide comparative evidence in the result section.
Response 1: Thank you for your insightful suggestions and proposed improvement measures. We have re-read the relevant literature on the various imaging techniques proposed in the article and summarized the expensive equipment required for these technologies (CT scanning, ultrasonic testing, lidar point cloud imaging, etc.) and the limitations of these methods. In the conclusion section, we provide a comparative analysis of the crown-width ratio prediction method proposed in this article and these methods from multiple aspects. Readers can clearly understand the cost and effort behind the differences and accuracies.
Comments 2: Likewise, it was stated that other intrinsic parameters of the trees also play important roles in determining pith position (Lines 68-82). However, such data were not considered in this paper. Please provide some factor analyses or relevant discussion as appropriate.
Response 2: Thank you for your valuable suggestion. We added other factors such as differences in light and soil moisture that affect the deviation of the pith from the center of the trunk in the Discussion section. We explained how uneven light and soil moisture affect the deviation of the pith from the center of the trunk and provided literature references.
Comments 3: Measurements expressed in Eq. (1) – (8) could be accompanied by the corresponding diagrams (overlay on the tree or its cut image) so that the reader can visualize and grasp the dimensions and actual appearance of these variables (Similar to what drawn in Fig. 1).
Response 3: Thank you for your feedback! Based on your feedback, we have added Fig. 1 below equations (1) – (8) to help readers can visualize and grasp the dimensions and actual appearance of these variables. (a) shows the actual appearance of the crown width-related variables. (b) shows the actual appearance of the disk radius-related variables.
Comments 4: While it was indicated that the linear model outperformed the others when predicting radius ratio from crown width ratio, the differences were only marginal. Besides, the R^2 was in fact quite low (about 0.4). From Fig. 3, the errors were mainly presented when crown width ratio were deviate from population mean. Please discuss whether how this would affect the subsequent pith prediction.
Response 4: Thank you for your valuable comment. We have added relevant content to the discussion as you suggested. In fact, in the process of locating the pith, we found that the error of the linear model prediction when the crown width ratio deviates from the population mean is smaller than that of the geometric center method. Therefore, we believe that it will not affect the subsequent prediction of the pith position.
Comments 5: While the crown width ratio to radius ratio function was derived and clearly expressed. That for predicting pith position from these variables was missing. Please explain.
Response 5: Thank you for your valuable feedback. We present the detailed procedure for predicting pith using these variables in Methods. Firstly, the crown width ratio NCR and ECR of each test tree were calculated. Then the radius ratio NRR and ERR were estimated with the linear model. Finally, the pith position of the test tree was estimated based on NRR and ERR.
Comments 6: The titles of vertical axes in Fig. 4(a) and (b) seems wrong. Please recheck. Besides they do not have any unit. Please provide for both vertical and horizontal axes. In fact, please also explain how they were calculated.
Response 6: Thank you for your suggestion! We modified Figure 4 and added the units. In (a), the horizontal axis represents the distance between the predicted pith and the true pith, in centimeters; the vertical axis represents the density, that is, the frequency of data occurrence in a unit interval. Specifically, the value on the Y axis represents the data distribution density near the horizontal axis. In (b), the horizontal axis represents the error between the predicted pith and the true pith; the vertical axis represents the density of the corresponding error.
Comments 7: On a similar note, please elaborate how “curve reaching its peak earlier” indicates better performance? The same comment applies to other contribution statements made in this study.
Response 7: Thank you very much for your detailed review of my manuscript. We explain in detail the meaning of the curves in Figure 4. By comparing the peak values ​​of the two curves, we can explain the meaning of reaching the peak earlier.
Comments 8: Comments on the Quality of English Language
- Due to language inaccuracies, various sentences are unnecessarily too complex and hence read confusing, e.g., “The crown ratio of the crown width in each direction to the sum of crown width in that direction and the opposite direction, and radius ratio of the radius of each direction to the diameter of that direction were calculated.” Please revising the writing style throughout.
Response 8: Thank you for your further comments. Regarding the sentence you pointed out as being too complicated, we have used a more concise sentence to describe it. “Firstly, based on the width of the annual rings in each direction of the disk, the radiuses of each direction were calculated. Then the total crown width and diameter of each tree were calculated in both the east-west direction and north-south direction respectively.” We carefully checked the entire text and revised overly complex sentences to ensure that our statement is easier to understand. If there are any omissions, please feel free to point them out.
- Other language errors were also found in the manuscript. Extensive editorial polishing is therefore mandatory.
Response 8: Thank you for your valuable feedback. We read the entire text carefully, found some linguistic errors and corrected them. I believe this revision addresses your concern and enhances the clarity of the sentence.
Reviewer 3 Report
Comments and Suggestions for AuthorsThe carefully examined article entitled “An algorithm for determining the pith position based on crown width size” proposes a new method for estimating the location of the pith of standing trees. Accurate estimation of the pith is an important issue in forestry applications such as measuring tree age rings and analyzing wood properties. Estimating the pith position with the width ratios of the crown is a new and different approach. This method has less error rate compared to the traditional geometric center method and is based on the ratios related to the width of the crown. The study is important in terms of presenting an experimental innovative approach. However, there are some methodological and writing deficiencies or points that need further development. By fixing these errors, the article will be better for publication.
1-The problem definition in the Introduction section of the article is not detailed enough. Deficiencies of existing studies should be included here and results showing that these deficiencies have been eliminated with the proposed method should be presented. In this respect, the article lacks basic motivation. The article should emphasize which deficiencies in the literature the proposed method overcomes.
2-The article's contribution to the literature should be emphasized in a few items at the end of the introduction section. What the existing methods are, what different techniques are used, and what their limitations should be mentioned.
3- The related studies section of the article is incomplete. Although the introduction section includes several existing studies showing that estimating the pith position in standing trees, studies in the literature, especially those conducted in recent years, should be included. The deficiencies or advantages of these studies should be evaluated.
4- The paper states that the Linear model was chosen, but the R² value is reported as only 0.405. This indicates that the power of the model is limited. Model performance can be improved by testing more complex models or ML algorithms.
5- The proposed method is limited to only two tree species. The differences in tree core features and crown structures may not provide generalizability. Conducting experiments on more species will increase the generalizability of the method.
6- Crown width measurements are prone to error as they can vary depending on various environmental factors such as wind, shade, etc. In this case, isn't it inevitable to prefer more precise methods such as LiDAR in measuring crown width?
7- Detailed information should be provided on the ease of use of the proposed approach in practical forestry applications in the article. It would be useful to add a discussion on the applicability of the method in the field. It should also be detailed whether this applied method requires more time or equipment compared to the geometric center method.
8- The reliability of the results can be increased by performing statistical significance analysis of the pith position estimation errors such as 7.6% and 10.1%. Whether the estimation errors create a significant difference can be determined by an ANOVA or t-test.
9-The Conclusions section is not detailed enough and should be rewritten. Additionally, the study does not include limitations. A more detailed discussion of its limitations should be included.
Author Response
Comments 1: The problem definition in the Introduction section of the article is not detailed enough. Deficiencies of existing studies should be included here and results showing that these deficiencies have been eliminated with the proposed method should be presented. In this respect, the article lacks basic motivation. The article should emphasize which deficiencies in the literature the proposed method overcomes.
Response 1: Thank you for your insightful suggestions and proposed improvement measures. We again summarize the shortcomings of existing research (CT scanning, ultrasonic testing, lidar point cloud imaging, etc.) and the limitations of these methods. In the conclusion section, we provide a comparative analysis of the crown-width ratio prediction method proposed in this article and these methods from multiple aspects. Readers can clearly understand the cost and effort behind the differences and accuracies. It is emphasized in the article that the proposed method overcomes the deficiencies presented in the literature.
Comments 2: The article's contribution to the literature should be emphasized in a few items at the end of the introduction section. What the existing methods are, what different techniques are used, and what their limitations should be mentioned.
Response 2: Thank you for your suggestion. We have supplemented the introduction on the basis of the original one, including: some existing methods, different technologies used by the methods. In the conclusion, we compare the method of the article with the existing methods, emphasizing the shortcomings of the existing methods overcome by the method of the article.
Comments 3: The related studies section of the article is incomplete. Although the introduction section includes several existing studies showing that estimating the pith position in standing trees, studies in the literature, especially those conducted in recent years, should be included. The deficiencies or advantages of these studies should be evaluated.
Response 3: Thank you for your valuable feedback. We have reorganized several existing studies on pith localization in the introduction section and added recent research in the article, such as Marichal et al. 2024” Automatic Wood Pith Detector: Local Orientation Estimation and Robust Accumulation”. And evaluate the deficiencies or advantages of these studies in the discussion section.
Comments 4: The paper states that the Linear model was chosen, but the R² value is reported as only 0.405. This indicates that the power of the model is limited. Model performance can be improved by testing more complex models or ML algorithms.
Response 4: Thank you for your further comment. In our testing, the linear model had the highest fitting degree. Linear models are simple and easy to calculate, and can be directly computed in field environments to estimate the position of the medullary heart.
Comments 5: The proposed method is limited to only two tree species. The differences in tree core features and crown structures may not provide generalizability. Conducting experiments on more species will increase the generalizability of the method.
Response 5: Thank you for your insightful suggestions. We give the shortcomings of the article's method in the discussion and analyze how adding tree species may increase the versatility of the article's method.
Comments 6: Crown width measurements are prone to error as they can vary depending on various environmental factors such as wind, shade, etc. In this case, isn't it inevitable to prefer more precise methods such as LiDAR in measuring crown width?
Response 6: Thank you very much for your detailed review of my manuscript. When measuring the crown width, we used a LiDAR and this is reflected in the method. But due to the large error in measuring the crown width, R2 is relatively low. We also analyzed the causes of experimental errors in the discussion.
Comments 7: Detailed information should be provided on the ease of use of the proposed approach in practical forestry applications in the article. It would be useful to add a discussion on the applicability of the method in the field. It should also be detailed whether this applied method requires more time or equipment compared to the geometric center method.
Response 7: Thank you for your feedback! We discussed and compared the advantages of the article proposed method with existing methods, showing the ease of use of the article method. We also compared it with the geometric center method, showing that the article method only takes a small amount of time to improve the accuracy of predicting the pith.
Comments 8: The reliability of the results can be increased by performing statistical significance analysis of the pith position estimation errors such as 7.6% and 10.1%. Whether the estimation errors create a significant difference can be determined by an ANOVA or t-test.
Response 8: Thank you for your suggestion. We use the t-test to improve the reliability of the results. The p-value of the t-test was 0.065. Therefore, there was a significant difference in the estimated results of these two methods at a significance level of 0.1.
Comments 9: The Conclusions section is not detailed enough and should be rewritten. Additionally, the study does not include limitations. A more detailed discussion of its limitations should be included.
Response 9: Thank you for your feedback! We have rewritten the results to be more detailed. We provide answers to the limitations of the article's methods in the discussion section.
Round 2
Reviewer 3 Report
Comments and Suggestions for AuthorsThe corrections have been taken into consideration by the authors.
