PONE-D-19-29708

Non-destructive monitoring of annual trunk increments by terrestrial structure from motion photogrammetry

PLOS ONE

Dear Dr. Mokros,

Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process.

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Both reviewers require substantial revisions before the manuscript can be properly reviewed. After reviewing the manuscript as well, I agree that the methods require (i) greater detail and (ii) improved writing to clarify existing statements. Indeed, there are cases in the methods description where one would need to guess what has been done. On the bright side, both reviewers believe the work has the potential to be of high interest to a broad readership.

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We would appreciate receiving your revised manuscript by Jan 17 2020 11:59PM. When you are ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file.

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We look forward to receiving your revised manuscript.

Kind regards,

John Toland Van Stan II, Ph.D.

Academic Editor

PLOS ONE

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2. In your Methods section, please provide additional location information, including geographic coordinates for the data set if available.

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Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Yes

Reviewer #2: Yes

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2. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: Yes

Reviewer #2: Yes

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3. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: Yes

Reviewer #2: Yes

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4. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: Yes

Reviewer #2: No

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5. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: General comment

The authors conducted a research on monitoring and accuracy assessment of annual trunk increments by terrestrial structure from motion photogrammetry. First, 240 perimeters of four tree species were measured by tape on three height level (0.8 m, 1.3 m and 1.8 m). Then, these perimeters were estimated by terrestrial structure from motion (SfM) photogrammetry techique. All data monitored from after-and before-vegetation season were used to calculate the annual increment. The paired t-test was used to confirm the statically significant difference between annual tree increments calculated from conventional measurements and from terrestrial SfM photogrammetry. Finally, the accuracy assessment of annual trunk increments determined by tape and terrestrial SfM photogrammetry were compared to results measured by increment borer method. Authors remarked “a significant part of forests remains unsuitable if the available terrestrial SfM photogrammetry were to be employed with current accuracy”.

Here I would like offer some comments as follows

Major comments:

1. Please add a flow chart of experimental steps in Methodology section (consist of image processing, results evaluation and accuracy assessment).

2. In Table 1, could you add mean of perimeter estimated from terrestrial SfM at each height level of four tree species?

3. From line 208 to line 217, the paired t-test was used for evaluating both results, please provide more detail of each tree (t=?, df=?, 95% confidence interval=?).

4. From line 305 to line 309. Could you show clearly a suitable or unsuitable part if the terrestrial SfM photogrammetry were applied in Fig. 6. Also, please make a legend of blue points and red area in Fig.6.

5. Please add conclusion section to reveal that the results archived from terrestrial SfM photogrammetry can or NOT be used for monitoring the annual tree increments based on accuracy assessment. And could the terrestrial SfM photogrammetry technique is replaced by the tape measurement?

Minor comments:

6. Line 260. Term “reconstruct of trees” can be replaced by “construct 3D model of trees”.

7. Line 267. Term “worst RMSE” can be replaced by “highest RMSE”.

8. From line 273 to line 287. Please move to introduction section.

9. I am not an English native speaker but I think the manuscript should be checked by an English native speaker.

Reviewer #2: The paper presents an application of structure from motion photogrammetry for measuring trunk diameter increments. This work is novel as it is the first example of measuring trunk increments using a photogrammetric approach and is likely to be of interest to the readers of Plos One.

The paper requires significant improvement in the writing and general presentation before being published. A number of sections are difficult to interpret. For example, the word distract is used instead of subtract in line 110, and units are missing throughout. Nevertheless, the novelty of the work and methods used appear to be sound as such I recommend minor revisions.

Other comments,

1. Some of the methods are not fully described, for example,

- line 146 "To calculate initial diameter and position of the tree we used the circle fitting algorithm [15]." The circle fitting method is not outlined and reference 15 is a comparison of multiple methods.

- line 153, how was the diameter derived from the polygon?

2. Figure 2 should provide a scale bar for each point cloud

3. The results often repeat the methods

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Reviewer #1: Yes: Nguyen Van Trung

Reviewer #2: No

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Non-destructive monitoring of annual trunk increments by terrestrial structure from motion photogrammetry

PONE-D-19-29708R1

Dear Dr. Mokros,

We are pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it complies with all outstanding technical requirements.

Within one week, you will receive an e-mail containing information on the amendments required prior to publication. When all required modifications have been addressed, you will receive a formal acceptance letter and your manuscript will proceed to our production department and be scheduled for publication.

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With kind regards,

John Toland Van Stan II, Ph.D.

Academic Editor

PLOS ONE

Additional Editor Comments:

The revised manuscript has addressed reviewer concerns. In particular, the revisions clarified the methodological elements and the overall workflow, and highlighted key findings/limitations throughout (including the addition of a formal conclusions section).

Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation.

Reviewer #1: All comments have been addressed

Reviewer #2: All comments have been addressed

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2. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Yes

Reviewer #2: Yes

**********

3. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: Yes

Reviewer #2: Yes

**********

4. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: Yes

Reviewer #2: Yes

**********

5. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: Yes

Reviewer #2: Yes

**********

6. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: All comments have been addressed. Therefore, the second revised manuscript was accepted for publication in PLoS ONE.

Reviewer #2: The authors have done a good job in addressing my initial concerns. The paper is now suitable for publication.

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7. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files.

If you choose “no”, your identity will remain anonymous but your review may still be made public.

Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy.

Reviewer #1: Yes: Nguyen Van Trung

Reviewer #2: No