Selection of Eucalyptus camaldulensis Families for Sustainable Pulpwood Production by Means of Anatomical Characteristics
Round 1
Reviewer 1 Report
Dear authors
I am sending the comments to the manuscript "Selection of Eucalyptus camaldulensis families for sustainable pulpwood production by principal component analysis and clustering for anatomical characteristics".
- line 94 " ..Then, they were divided into small segments 1 cm in length".
?Why not radial positions e.g three radial positions 30 %60% and 90% of the radius from the pith to cambium?
- line 98 …"..of stem diameter "
?The mean of overbark or wood diameters ? How many replicates per tree were analysed?
- line 101...".The mean and standard deviation (SD) for each family were calculated based on data from five trees"
?How many samples were taken per tree ? The number of samples was the same for all trees?
- line 156 .."The anatomical characteristics at the outermost part of the stem."
?Clarified the “outermost part of the stem”?
-line 168 " The results obtained in the present study were similar to those reported by Ohshima et al. [13,14], except for the slenderness ratio and solids factor " Please improved the discussion
-line 170-171 .."Although the fibre length in the present study was longer than that reported by Ohshimaet al. [21], wood fibre and fibre lumen diameter had almost the same values in both studies [20]? Please clarified this point
Author Response
Comments for reviewers
Thank you very much for your valuable suggestions and comments on our manuscript. Our comments and revised points are as follows.
For Reviewer 1
1) Line 94 - " ..Then, they were divided into small segments 1 cm in length".
Why not radial positions e.g. three radial positions 30%, 60% and 90% of the radius from the pith to cambium?
RESPONSE: We collected the samples from progeny test site. Thus, we have limitation of the sampling, and we have to avoid the any damage of trees. Thus, we only collected the wood samples from cambium to 2 cm from cambium.
2) Line 98 - " ..of stem diameter "
The mean of over bark or wood diameters? How many replicates per tree were analysed?
RESPONSE: We have added the word of 'over bark' in the title of Table 1.
3) Line 101 - "The mean and standard deviation (SD) for each family were calculated based on data from five trees"
How many samples were taken per tree? The number of samples was the same for all trees?
RESPONSE: Yes, the number of samples was the same as the number of trees (five trees in each family). We have added detail information of the number of samples in in 'Materials and Methods'.
4) Line 156 - "The anatomical characteristics at the outermost part of the stem.
Clarified the “outermost part of the stem”?
RESPONSE: We have revised it.
5) Line 168 - "The results obtained in the present study were similar to those reported by Ohshima et al. [13,14], except for the slenderness ratio and solids factor " Please improved the discussion?
RESPONSE: We have revised it.
6) Line 170-171 - "Although the fibre length in the present study was longer than that reported by Ohshima et al. [21], wood fibre and fibre lumen diameter had almost the same values in both studies [20]? Please clarified this point.
RESPONSE: We have revised it.
Reviewer 2 Report
The research brings useful findings regarding anatomical characteristics and derived-wood properties of 15 half-sib families of E. camaldulensis, including evaluation/estimation of their impact on pulp and paper quality. Below is the list of comments/questions to be addressed in the revised manuscript if possible:
- The objective/aim of the research could be formulated more specifically at the end of the Introduction.
Materials and Methods:
- Line 97 and line 104 determination of LC by acetyl bromide method is mentioned twice, not necessary.
- Could you please clarify if for the measurements in the framework of this research, the same samples (5-years old) were used as for the study Kuramochi et al. (2014)? Did the values presented in Table 1 and Table 3 were measured at the relatively same period? If not, could the time difference/storage conditions affect the results?
- I am not well familiar with it, are the families within the camaldulensis having numerical IDs, not names, etc.?
- For better visualization and higher attractively of the paper, I would recommend adding some pictures, e.g. transverse images, preparation of samples for determination of anatomical characteristics within the text or in graphical abstract.
- Line 116-125 the total number of images or measurements per image per parameter could be added.
- Table 2: use Microsoft Equation Editor or the MathType add-on for equations (formulas).
Results and Discussion:
- From lines 165-169 follow that derived-woof properties do not differ in dependence on the tree age, right?
- Lines 185-188: ‘’.....suggesting that the quality of pulp and paper produced from the wood of this species can be improved through improvement of fibre morphologies under appropriate tree breeding programmes’’. It seems suitable to give some examples here, techniques or programmes, based on references, thus, the number of references will be higher, and that will also be beneficial.
Author Response
Comments for reviewers
Thank you very much for your valuable suggestions and comments on our manuscript. Our comments and revised points are as follows.
For Reviewer 2
1) The objective/aim of the research could be formulated more specifically at the end of the Introduction.
RESPONSE: We have revised final paragraph in 'Introduction'.
2) Line 97 and line 104 determination of LC by acetyl bromide method is mentioned twice, not necessary.
RESPONSE: We have omitted explanation of determination of LC by acetyl bromide method from the Note of Table 1.
3) Could you please clarify if for the measurements in the framework of this research, the same samples (5-years old) were used as for the study Kuramochi et al. (2014)? Did the values presented in Table 1 and Table 3 were measured at the relatively same period? If not, could the time difference/storage conditions affect the results?
RESPONSE: We have used the same samples that used by Kuramochi et al. (2014). Preparation of samples for anatomical characteristics was also conducted in 2014- 2015. Then, experiments for anatomical characteristics were conducted in 2017-2018. We keep the wood samples for observing the SEM in desiccator after ion spattering.
4) I am not well familiar with it, are the families within the E. camaldulensis having numerical IDs, not names, etc.?
RESPONSE: In this site, families have been managed by ID number.
5) For better visualization and higher attractively of the paper, I would recommend adding some pictures, e.g. transverse images, preparation of samples for determination of anatomical characteristics within the text or in graphical abstract
RESPONSE: We have added the transverse images as Figure 2.
6) Line 116-125 the total number of images or measurements per image per parameter could be added
RESPONSE: We have added the information about total number of images.
7) Table 2: use Microsoft Equation Editor or the MathType add-on for equations (formulas).
RESPONSE: We have revised formula in Table 2.
8) From lines 165-169 follow that derived-wood properties do not differ in dependence on the tree age, right?
RESPONSE: Unfortunately, we did not know the effects of age on these properties. In the future experiments, we will try to clarify it.
9) Lines 185-188: ‘’.....suggesting that the quality of pulp and paper produced from the wood of this species can be improved through improvement of fibre morphologies under appropriate tree breeding programmes’’. It seems suitable to give some examples here, techniques or programmes, based on references, thus, the number of references will be higher, and that will also be beneficial.
RESPONSE: We have added a reference.
Reviewer 3 Report
See attached file
Comments for author File: 
Comments.pdf
Author Response
Comments for reviewers
Thank you very much for your valuable suggestions and comments on our manuscript. Our comments and revised points are as follows.
For Reviewer 3
1) Title: I recommend shortening it by removing the allusion to PC analysis and clustering “Selection of Eucalyptus camaldulensis families for sustainable pulpwood production by means of anatomical characteristics”
RESPONSE: We have revised it.
2) Line 42: It would be welcome to incorporate some approximate data of the area planted with Eucalyptus spp. in the world, as well as that planted with E. camaldulensis.
RESPONSE: We have added the information of Eucalyptus plantation areas.
3) Line 54: Please, check this sentence “… resulting in bulkier paper with the area has a weak bond” The word highlighted should be “has” or “having”.
RESPONSE: We have revised it.
4) Lines 64-65: “Most E. nitens trees showed principal component (PC)1 values that indicate basic density, while most E. globulus trees showed higher PC2 values, which indicate fibre quality and stem diameter”. Why does PC1 indicate basic density and PC2 fibre quality? In a principal component analysis, the variables included in PC1 and PC2 vary depending on the set of variables entered and their values. Please, check this sentence.
RESPONSE: Carrillo et al. (2017) applied PCA analysis for combined data obtained from different two species. They reported that basic density, and fibre quality and stem diameter contributed PC1 and PC2, respectively. From figure of PCA scores, they explained tendency in each species.
5) Line 85: Please, show the climate data of the plantation site: mean annual temperature, mean annual rainfall, as well as a comment on the annual evolution of temperatures (which are, more or less, homogeneous throughout the year) and rainfall (which has a dry season and another wet).
RESPONSE: We have added the figure of monthly mean temperature and precipitation as Figure 1.
6) Lines 87-88: What was the final spacing after the thinning?
RESPONSE: We have added the spacing after thinning.
7) Line 92: “Of the measured trees, five trees in each family were randomly selected, and a total of 75 trees from 15 families were used” Normally, 75 trees are enough to carry out a study of these characteristics. However, 5 trees per family are few to characterize a family, since it does not cover all the variability. In a progeny study, it is common to use many more plants per family.
This aspect must be taken into account when discussing the results and presenting the conclusions. It should be noted in the text that the differences between families found should be taken with caution since only 5 plants per family are not fully representative of the whole family. However, the results from this study could have a high applicability to select genotypes (clones) with better characteristics for pulp production.
If there were only 8 trees left per family (line 88) and 5 of them were randomly chosen, is it possible to provide more information about these 8 trees? Are these trees selected for their superior growth within the family? etc.
RESPONSE: At first, we randomly selected six trees from remained eight trees in each family. Then, five trees were selected from six trees on the basis of stem diameter (trees with average stem diameter within a family). Due to limitation of sampling, we obtained the samples from five trees in a family.
8) Lines 92-94: “Core samples (5 mm in diameter and 2 cm in length from the cambium) were collected at 1.3 m above the ground using an increment borer (Haglöf, Sweden). Then, they were divided into small segments 1 cm in length to determine…” The samples are too small to represent the entire stem (10 cm DBH), from the pith to the cambium. In addition, it must be indicated at what time of year these samples were taken and in which orientation (N, S, E, W). These aspects are important because being samples of small length (2 cm), taken from the cambium, they represent the growth of the last "ring" and the size and frequency of the xylem vessels, as well as the size of the fibres could be influenced by the precipitation fallen during the last months.
It should be noted in the text that the results must be taken with caution since a small sample of a part of the main stem does not always represent the entire stem.
The answers to these questions should be shown in the text: was a single sample taken per stem? Were all samples taken in the same orientation (N, S, E, W)? At what time of year were the samples taken?
RESPONSE: We did not take samples from specific orientation (N, S, E and W). We collected the samples from random circumference position at 1.3 m above the ground level in a tree. We have added information of the number of samples in “2.1 Wood sampling” in Materials and Methods.
9) Table 1: The data shown in Table 1 correspond to a previous work (Kuramochi et al., 2014, tables 1 and 2). However, it has been partially modified and the values shown here are not exactly the same as those shown by Kuramochi et al. Have the data been recalculated? Have outliers data been removed? Please clarify what type of modification the data has undergone.
RESPONSE: We have recalculated the data from six trees to five trees (used in the present study). We have added the explanation of modification in Table 1.
10) Lines 122-125: “In addition, three digital images at each radial position were used to determine vessel frequency. At each radial position, the vessel diameter was measured for 30 vessels, while fibre diameter, fibre lumen diameter and fibre wall thickness were measured for 50 wood fibres.” If 30 vessels and 50 fibres were measured in each radial position, please clarify whether it is 30-50 data per family and position, or 30-50 data per tree (sample) and position. This can affect the statistical analysis since, if they are by family, it is possible to carry out an ANOVA as described in lines 137-140. However, if they are per tree, possibly a nested model should have been included in the ANOVA, with the tree within the family. Please, clarify this in lines 122-125 and 137-140.
RESPONSE: We have added the explanation in “2.2 Anatomical characteristics” and “2.4 Data analysis” in Materials and Methods.
11) Lines 136-137: “Data on stem diameter, tree height, basic density, lignin content and fibre length were taken from our previous paper (Table 1 [4]).” As not all the authors of this article coincide with those of Kuramochi el al., then it is not appropriate to say our previous paper, but rather to say of a previous paper. Please, replace “our” by “a”.
RESPONSE: We have revised it.
12) Lines 152-152: It is recommended to cite Moglia et al. (2008), as well as include a comment on the differences that can be found in the same stem depending on the distance to the pith of the extracted sample. It should be noted in the text that the results should be taken with caution since a small sample of a part of the main stem does not always represent the entire stem.
RESPONSE: We have added the reference of Moglia et al. (2008).
13) Lines 232-234: “Among the families, significant differences were found in fibre diameter, fibre lumen diameter, and Runkel ratio. For other derived-wood properties, the p values obtained by an ANOVA test were 0.048–0.078, indicating that pulp and paper quality might be improved by selecting families with good anatomical characteristics” Please, check these values. According to tables 3 and 4, p-values for other derived-wood properties, apart from fibre diameter, fibre lumen and Runkel ratio, were 0.050 for FC to 0.088 for FWT. Please, also check lines 25-26 in the Abstract.
RESPONSE: We have revised the sentences.
Round 2
Reviewer 3 Report
This is a revised and improved version of an earlier version. The authors have taken into account the revewers comments.
Therefore, I have no problem to recommend this manuscript for publication.
Please, only one minor detail. Check this sentence (Line 188): "...most part (position from the cambium to 2 cm position from cambium) of the stem..."
