The Predictive Accuracy of Modulus of Elasticity (MOE) in the Wood of Standing Trees and Logs

Round 1

Reviewer 1 Report

Dear Authors

I had the opportunity to review (16 pages) your research proposed for Forests under the name "The predictive accuracy of modulus of elasticity (MOE) in the wood of standing trees and logs". The article deals with the very interesting topic which investigated the predictive accuracy of non-destructive analysis of the MOEd (dynamic elastic modulus) in standing trees and logs of a 22-year-old poplar clone and to examine the relationship with MOEs (static elastic modulus) in sawn specimens. Despite interesting topic and analyses, I present some suggestions/questions which should be considered in my opinion for this article.

 

Comments for author File: Comments.pdf

Author Response

Dear Reviewer 1,

We are very grateful for your suggestions which have helped improve the quality of our manuscript.

• Authors stated extensive used references (75) but in discussing the results were used only 20 references so that extensive of critical discussion is lacking. Authors have to more discussion with other similar articles. Please, add missing discussing.

Response: Thanks. We extended and modified the discussion section, also following the other reviewer's recommendations.

• Incorrect stated citation.

For example:

Discussion.

1. Furthermore, these results are consistent with previous results reported by Ishiguri et al. [65], and Madhoushi and Daneshvar [9]........
2. Compared to this research, Gallego et al. [54] found values slightly ....
3. Similar to these results, Rescalvo et al. [47] and Gallego et al. [54] founded a significant ..... etc.

Correct is only [number]. Please correct this in all pages of article.

Response: Thanks for your comment. This way of citing references is accepted by the journal. Even looking at the latest volume of Forests published, there are several articles that adopt this type of citation.

• The introduction should outline why the process being analysed is important to know. Each reference should be referred to at length. The authors cite references in whole sets, e.g.

As reported by several

1. authors [1-6], wood quality can be defined as a set of characteristics that make woody ......
2. For this reason, several studies have been conducted in recent years to characterize

the poplar wood from standing trees using acoustic waves [45-53] but only a few .......... etc.

Please, adjust this mistake.

Response: Thanks for your comment. We have avoided the use of whole citations sets

 

Author Response File: Author Response.docx

Reviewer 2 Report

This paper presents original (but not necessarly innovative) results on NDT to assess wood properties (MOE) based on standing trees and logs and compared to a standard methodology. Only one clone of poplar from a unique site was tested.

The study was properly introduced and the research properly conducted and described.

Nevertheless the presentation of results is mostly redundant (tables and text are repeating results, + graphs), the writing is long and repetitive: it should be shortened and somehow summarised; some tables joined together, graphs should be favored in this case as they are more informative than tables as they clearly show the distribution of data and help explaining some results.

In addition, some results are missing and should be presented (MC, density, correlations of these traits + diameter with MOE's...   variation within log sections).

The Discussion is rather hard to follow and results should be more systematically discussed (level of MOE's among techniques, variation within sections and along sections, correlations among MOE's, links with other traits) with the right references.

For the Conclusion: it is unclear what the authors consider as the best way to assess MOE from NDT because of the variability observed along the stem. Any recommendation to be proposed?

Some details are provided in the attached file.

 

 

 

 

 

 

Comments for author File: Comments.pdf

Author Response

Dear Reviewer 2,

We greatly appreciated your commitment and constructive comments regarding our submitted manuscript. More detailed changes can be seen in the tracked changes of the current manuscript.

 

Page 1

• Thanks for your comment. We have made all the changes (deletions, additions, and/or substitution of text) as you have suggested.

 

Page 2

• Instead “observation”:

Thanks. We have replaced “measurements” with “appraisal”.

• is it the correct reference here? Does not seem to be!:

We have substituted the reference 13 with the right reference.

 

Page 3

• Reference?:

We have added the missing reference.

• I guess the trees have been regularly pruned?:

Yes, the considered plantation has been regularly pruned. We have added a sentence that clarify it.

• Thanks. We have made all the changes (deletions, additions, and/or substitution of text) as you have suggested.

 

Page 4

• do you really consider acoustic velocity technique on logs as nondestructive? Not really indeed as you are working on logs from harvested trees: we have added the missing reference.

Thanks for your comment.

Non-destructive evaluation is the identification of the physical and mechanical properties of a material without altering its end use. The most commonly used physical principles in non-destructive evaluation are: acoustic, ultrasonic, microwave, imaging, laser and X–ray (Ondrejka, V., Gergeľ, T., Bucha, T., & Pástor, M. (2021). Innovative methods of non-destructive evaluation of log quality. Central European Forestry Journal, 67(1), 3-13.). Therefore, since the application of acoustic technique on logs allows to keep intact the mechanical characteristics of the wood, it is to be considered a Non-destructive method.

• We have made all the changes (deletions, additions, and/or substitution of text) as you have suggested.

 

Page 5

• Is it a density at 12%?:

Yes, the density was calculated at 12 % MC. We have added that percentage to specify it.

 

Page 6

• Thanks. We have made all the changes (deletions, additions, and/or substitution of text) as you have suggested.

 

Page 7

• Guess it is Pearson coefficient?:

Yes, it is. We have added “coefficient” to specify it.

• Instead of or in addition to St.dev., I would suggest to add the coefficient of variation, which will highlight the larger variability observed for each trait at H3 compared to H1.

This is an interesting result which also explains why the overall results (at tree level) are 'so' good (drawn by H3 measurements).:

As you suggested, we have added the coefficient of variation to the table 2.

• Are missing data on MC, density:
• Thanks for your suggestion.

To determine the water content (MC) in green and dry conditions, the dry oven method was applied, according to EN 408. The samples were sized and conditioned in the climate cell to reach a humidity of 12% according to the regulations before being subjected to mechanical tests. In addition, the mass and size of the wood samples were recorded to determine the density. This approach was conducted to have an average humidity value of the trees just felled (88%) and the average value of the specimens conditioned in a climatic cell (12%). This study, given the already recognized homogeneity of the intrinsic characteristics of Poplar Clone I-214 wood, aimed at a methodological approach to determine the predictive accuracy of the non-destructive analysis of MOEd in standing trees and logs of a 22-year-old poplar clone and to examine the relationship with the typical MOEs evaluation in sawn specimens.  Your comment is extremely interested and has been considered by authors as a possible target for a future research article. In fact, it would be interesting in subsequent study to compare these results with the density and water content distributed along three different heights, using clones or different species of Poplar or other wood species.

• We have made all the changes (deletions, additions, and/or substitution of text) as you have suggested.

 

Page 8

• I suggest to join the two tables together (3 & 4) by using one above-diagonal for a set of results and the other half for the second set;:
• Thanks. We have joined tables 3 & 4 and eliminated the redundant data.
• Thanks. We have made all the changes (deletions, additions, and/or substitution of text) as you have suggested.

 

Page 9

• In Table 5, remove every third and fourth lines for each height: redundant results. Instead join results of Tables 5 and 6 in a unique table;:
• We have joined tables 5 & 6 and eliminated the redundant data.
• We have made all the changes (deletions, additions, and/or substitution of text) as you have suggested.

 

Page 11

• Would be worth to have also a table with links between MOE's and diameter, MC, density:
• you can see the answer at the above comment “Are missing data on MC, density”
• where can we see this? Could internal knots from branches (probably more dense at 30-130 cm than at 230-330 cm have an influence as well? Where do we see this?
• Thanks for the comment. From the bibliographic research carried out and reported along the text it is recognized that along the height of the trunk of the plant the MOE is influenced by various factors including the water content. The study carried out by us reported a slight variation of the modules along the height and since:
• an excessive amount of knots was not found in the specimens obtained;
• The influence of the bark was not considered as its thickness is minimal in clone I-214.

The authors assumed that this small change is probably also due to a change in water content.

• I guess in this section you want to insist on the small difference between moduli on standing trees and logs because of low level of wood defects...Must be re-phrased.

Thanks for your suggestion. We have re-phrased the sentence.

• We have made all the changes (deletions, additions, and/or substitution of text) as you have suggested

 

Page 12

• Where do we see this?:

We have added “considered the known morphological characteristic of Populus × euroamericana clone I-214,” to better explain the concept related to the citation.

• What is the link with the previous sentence? you were speaking of correlations and now you talk about measurements differences?:

We have re-phrased the sentence.

• Should be placed above:

We have moved the sentence above.

• Very long sentence! very much redundant with what is said above!:
• We have deleted from “the stress wave ….” to “…. At the same time,”.
• In the Discussion, some aspects should be further discussed:

- greater variability upper in the trees than at the bottom,

- consequences of changes of MOE measurement with height: what is recommended for routine assessment?:

• We have integrated the suggestions into the text.
• What do you mean?:

We have re-phrased the sentence to better explain the concept.

• We have made all the changes (deletions, additions, and/or substitution of text) as you have suggested

 

Page 14

We have substituted the reference 13 with the right reference.

 

Page 15

• = ref. # 18:

Yes, 53 was equal to 18, so we have deleted it.

• ???:

We have added the missing authors.

• We have made all the changes (deletions, additions, and/or substitution of text) as you have suggested

Author Response File: Author Response.docx

Reviewer 3 Report

 

The article is well written and structured. It is suggested to justify its novelty and contributions, especially with respect to the research carried out by Gallego et al (2021) on the same clone of the species and following an equivalent methodology. Some aspects of the article that are not clear or need to be modified are listed:

1)     Objectives:

Determine in the objectives the novelty of the work since currently, as it is written, it is not reflected.

2)     Methodology:

About the specimens used for destructive tests:

- Indicate and detail how they were obtained, if they were small clear specimens and if they were all radial.

- Explain the reason why they were not subjected to NDT before performing destructive tests.

- Identify the area of ​​the trunk in which the specimens for destructive tests were obtained. Measurements made on logs of wood and on the trunk with specimens without identifying the location is being compared, taking into account that this location can determine variations of the MOEs in some species.

- It is suggested to indicate the standard deviation of the values ​​obtained in a log, only the mean is indicated.

- Justify the reason for using Sandoz's moisture content (MC) correction coefficient instead of those proposed in the most recent bibliography and specific for different species. It is considered of 0.8% for every 1% of MC, but the logs are above the Fiber Saturation Point (FSP), therefore different coefficients must be considered above and below FSP.

3)     Results:

The tables can be presented in a more compact way, grouping them, and reducing their number.

It is suggested to indicate the standard deviation obtained in each group of 50 specimens analyzed for each log and each tree (already indicated above).

Table 5 has an error in the header (review).

4)     Discussion:

It is assumed that, as has been commented in the methodology, the data have been corrected taking into account the MC, therefore, the following statement does not make sense:

“In general, the stress wave speed in the longitudinal direction slightly increases with the height of the stem. This trend could be justified by the higher moisture content in the basal part of the trunk”

The following statement is obvious in NDT, as the authors themselves comment in the state of the art, so it does not add novelty to the discussion “in fact, previous studies [20, 64] have reported that humidity is one of the causes of the reduced wave speed in trees”.

5)     Conclusions

They are written in a very general way, coming at some point to seem like an abstract. Qualitative terms are used, such as slightly.

The first paragraph of the conclusion states again the objective of the work. The last two paragraphs are written as a discussion, with citations, it is suggested to move them to this section and complete the conclusions with the specific research proposals that emerge from this work.

6)     Bibliography

Standardize the bibliography. Some publications are presented with their short title and others with the full title.

Other themes:

The acronym MOEs or MOEd is not always kept, it is referred to as “dynamic elasticity moduli”, “static elastic modulus” or as “static MOE”

Author Response

Dear Reviewer 3,

We are very grateful for your suggestions but yesterday we wrote to the Editor for guidelines since the comments you sent as a third reviewer arrived later than the others and very close to the deadline. The Editor has decided that the manuscript can be submitted with the modifications recommended by the first two reviewers.

 

 

 

Da: Vlad Vatavu
Inviato: martedì 19 luglio 2022 22:42
Oggetto: Re: R: [Forests] Manuscript ID: forests-1807933 - Major Revisions

 

Dear Ms. Cataldo,

 

Hope this email finds you well.

 

Yes, you can submit it now as it is.

 

Thank you.

 

Kind regards,

Mr. Vatavu V Vlad Viorel

Assistant Editor, MDPI Romania

Boulevard Dacia 30, 010403 Bucharest, Romania

Tel.: +40 0364 150134

Email:[email protected]

 

 

 

Da: Maria Francesca Cataldo
Inviato: martedì 19 luglio 2022 16:36
A: [email protected]
Oggetto: R: [Forests] Manuscript ID: forests-1807933 - Major Revisions

 

Dear editor,

we have concluded the revision of the manuscript but only today we have seen on the home page dedicated for this review, the third revision. Now we are ready to submit the paper reviewed following the comments from the first two reviewers. Can we submit the paper now, without the third revision?

Otherwise, we ask you to have more ten days to make the third revision.

 

We look forward to hearing from you soon.

Maria Francesca Cataldo

PhD in Agricultural, Food And Forest Sciences

Department of AGRARIA

University “Mediterranea” of Reggio Calabria (Italy)

Round 2

Reviewer 2 Report

Dear authors,

Thanks for having taken into account my comments and correcting the manuscript accordingly.

However, it seems that some major comments in the 'Suggestions for Authors' have not been seen or considered, namely:

1) 'Nevertheless the presentation of results is mostly redundant (tables and text are repeating results, + graphs), the writing is long and repetitive: it should be shortened and somehow summarised; some tables joined together (done but in Tables 3 & 4, lines relating to N should be suppressed and this information joined to the table headings as figures are always the same) , graphs should be favored in this case as they are more informative than tables as they clearly show the distribution of data and help explaining some results.

2) 'The Discussion is rather hard to follow and results should be more systematically discussed (level of MOE's among techniques, variation within sections and along sections, correlations among MOE's, links with other traits) with the right references.'

3) 'For the Conclusion: it is unclear what the authors consider as the best way to assess MOE from NDT because of the variability observed along the stem. Based on results, the authors should come with proper recommendations on how to use NDT for MOE assessment. '

Finally I consider that the manuscript still needs some additional work to make it more easily readeable and attractive.

 

Author Response

Dear Reviewer 2, 

Thanks again for the comments and suggestions that allow us to improve our submitted manuscript. Changes that are more detailed can be seen in the tracked changes of the current manuscript. 

• 'Nevertheless the presentation of results is mostly redundant (tables and text are repeating results, + graphs), the writing is long and repetitive: it should be shortened and somehow summarised; some tables joined together (done but in Tables 3 & 4, lines relating to N should be suppressed and this information joined to the table headings as figures are always the same) , graphs should be favored in this case as they are more informative than tables as they clearly show the distribution of data and help explaining some results. 

Thanks for the right suggestion. The manuscript has been modified, the results have been shortened, and informative graphs have been added showing the trend of the data. 

 

• 'The Discussion is rather hard to follow and results should be more systematically discussed (level of MOE's among techniques, variation within sections and along sections, correlations among MOE's, links with other traits) with the right references.' 

Thanks for your comment. We have made all the changes (deletions, additions, and/or substitution of text) as you have suggested. 

 

• 'For the Conclusion: it is unclear what the authors consider as the best way to assess MOE from NDT because of the variability observed along the stem. Based on results, the authors should come with proper recommendations on how to use NDT for MOE assessment. ' 

Thanks for your comment. We have made all the changes (deletions, additions, and/or substitution of text) as you have suggested.