Weathering Behaviour of Cunninghamia lanceolata (Lamb.) Hook. under Natural Conditions
Round 1
Reviewer 1 Report
The introduction should give more information, as a lot of studies dealing with wood weathering were conducted.
Line 68-69: It is not understable what exactly was done on microtome. What was the aim of drying samples in 60 oC?
Line 70: What does Summer 2017 mean? How to repeat your research?
Line 98: It can not be said about determination wood density in radial direction. Only along the tree heigh variability was presented. Presenting wood density for sapwood and heartwood is something different. Why did you obtained such difference? It requires comment.
Line 193: I recommend to include wood images before and during weathering.
Lines 268-269: What kind of mechanical properties were determined? Morover, I do not see any chemical analysis.
In my opinion, that work need more experiments to conduct and to proper analysis obtained results.
Author Response
Point 1: Line 68-69: It is not understable what exactly was done on microtome. What was the aim of drying samples in 60 ℃?
Response 1:
Line 66-67: Colour measurements and microstructure observation samples were cut using a sledge microtome to reveal three sections.
Drying samples in 60 ℃, to reduce the degradation of samples in the room. The samples are still affected by fungi and humidity indoors.
Point 2: Line 70: What does Summer 2017 mean? How to repeat your research?
Response 2:
Refer to previous articles and select relatively significant environmental conditions. Summer has strong UV light and high temperatures and high humidity conditions.
In the summer of 2018, a repeated experiment was conducted in parallel with the comparative experiment, and the results were the same as those of 2017.
Point 3: Line 98: It can not be said about determination wood density in radial direction. Only along the tree height variability was presented. Presenting wood density for sapwood and heartwood is something different. Why did you obtained such difference? It requires comment.
Response 3: Please provide your response for Point 2. (in red)
Line 104-105: The difference in density in the radial direction was due to the increase in cambium age, as has been reported in many studies on the radial variation of wood [29-31].
At the beginning, I made a comparison between mature wood and juvenile wood in the radial direction. For some reason, I should change that. I have some hesitation between the “inner-outer” and “sapwood-heartwood”.
Point 4: Line 193: I recommend to include wood images before and during weathering.
Response 4:
Thank you for your recommendation. In this experiment I forgot to take pictures after each exposure times. In the future, I will take photos and compare the samples in time.
Point 5: Lines 268-269: What kind of mechanical properties were determined? Moreover, I do not see any chemical analysis.
Response 5:
I'm sorry. The words for mechanical properties and chemical analysis have been deleted.
Dear reviewer,
Thank you for your kindness.
Best regards.
Author Response File: 
Author Response.doc
Reviewer 2 Report
This paper work is interesting, It needs some improvements though.
1.Title must be changed. The paper deals with natural weathering. A more suitable title should be written.
2.Technical English language can be improved. There some errors in the text
(e.g., lines 19-20,
3.English should be British English, not American.
4.Maybe, the Conclusions part can be written more carefully, and better.
In some parts, the word 'degradation' can or should be replaced by the suitable word, weathering. The authors actually to the weathering effects are referred to.
From my knowledge, some literature can be included, this is just an advice; (especially on the wood weathering), like
a.Fungal and bacterial colonies growing on weathered wood surfaces, DOI
10.1080/17480272.2018.1443975 (a very good review)
b.
|
FTIR spectroscopic studies of the photo-discoloration of Chinese fir this one is related with the same wood species! |
c. Colour changes of wood materials due to natural and artificial weathering
DOI 10.1080/17480272.2012.696699
In overal, the paper is worth it to be published in the journal, but it needs some rather minor editing.
Thanks.
Author Response
Point 1: 1.Title must be changed. The paper deals with natural weathering. A more suitable title should be written.
Response 1:
New Title: Variation in Intrinsic Weathering Behaviour of Cunninghamia lanceolata During Natural conditions
Point 2: Technical English language can be improved. There some errors in the text (e.g., lines 19-20,
Response 2:
Line 20-21: Therefore, this paper provides a basis for the pretreatment of Cunninghamia lanceolata to prevent weathering under natural conditions.
Point 3: 3. English should be British English, not American.
Response 3:
I try to write this article again using British English, please review it.
Point 4: In some parts, the word 'degradation' can or should be replaced by the suitable word, weathering. The authors actually to the weathering effects are referred to.
Response 4:
I changed some words ‘degradation’ in the article. (e.g., the title and others)
Point 5: From my knowledge, some literature can be included, this is just an advice; (especially on the wood weathering), like
Response 5:
Thank you so much for this advice. I found these articles. They are very useful to me.
a. Fungal and bacterial colonies growing on weathered wood surfaces, DOI 1080/17480272.2018.1443975 (a very good review)
Use it in reference [45].
b. FTIR spectroscopic studies of the photo-discoloration of Chinese fir
this one is related with the same wood species!
Use it in reference [57].
c. Colour changes of wood materials due to natural and artificial weathering
DOI 10.1080/17480272.2012.696699
Use it in reference [42].
Dear reviewer,
Thank you for your kindness.
Best regards.
Reviewer 3 Report
Dear authors,
Your work show interesting results about influence of wood position in logs to natural weathering performance of Chinese fir.
Experiment is well planned and results are clearly presented.
Some comments which can help you to improve quality of your manuscript:
The title – try to add something about your main aim: influence of location of wood in tree or log…
Abstract
L15: Please add which characteristics were compared
L19: I am not sure if density is not better word in comparison with specific gravity – please change also in all text of this manuscript…
Intro:
L31-L33: It is out of research interest of this work – please remove these two sentences
L36: termites and fungi resistance – some reference is necessary to add
Materials and Methods
L63: which air conditions? It must be specified: temperature, humidity…
Results
L132: Why pits were destroyed so fast – try to find and add reference about their chemical composition – mostly by pectins
L161 – Which is depth of UV-absorption into wood – Kataoka an Kiguchi in your references
L183 – decay is used for degradation of wood by wood destroying fungi – change it (for example to degradation)
Discussion
L263: Chemistry was not researched in this study – please remove this word.
Final
Please, by reviewer opinion will be better choice to write in results only results of your work and all parts of discussion (for example L141-LL150; L152-LL164; L216-L223 and others….) give to the 4-th part of article – Discussion. Now there are more repeating parts in this article – reviewer have found 3 or 4 times the same sentence about photo-degradability of lignins… This way of presentation can improve quality of this interesting paper.
After revisions reviewer recommends this article for publication.
With Best Regards
Author Response
Point 1:
The title – try to add something about your main aim: influence of location of wood in tree or log…
Response 1:
New title: Variation in Intrinsic Weathering Behaviour of Cunninghamia lanceolata During Natural conditions
Point 2:
L15: Please add which characteristics were compared
L19: I am not sure if density is not better word in comparison with specific gravity – please change also in all text of this manuscript…
Response 2:
L15-L16: The structural degradation and discoloration of wood surfaces before and after exposure were compared.
I already changed ‘specific gravity’ to ‘density’ in all text of this manuscript.
Point 3:
Intro:
L31-L33: It is out of research interest of this work – please remove these two sentences (already removed)
L36: termites and fungi resistance – some reference is necessary to add
Response 3:
L31-L32: Cunninghamia lanceolata has a fragrant smell and contains cypress camphor. The timber of this species is strongly rot-resistant and it is not easily eaten by termites [3,5-7].
Point 4:
Materials and Methods
L63: which air conditions? It must be specified: temperature, humidity…
Response 4:
L58-L60:Owing to different growth rings, at 1, 2, 3, and 4 m from the ground, a sample of each three growth ring positions were cut to measure the density of the wood in a conditioning room at 20°C and 65% relative humidity.
Point 5:
Results
L132: Why pits were destroyed so fast – try to find and add reference about their chemical composition – mostly by pectins
L161 – Which is depth of UV-absorption into wood – Kataoka an Kiguchi in your references
L183 – decay is used for degradation of wood by wood destroying fungi – change it (for example to degradation)
Response 5:
L134-L140: Intact bordered pits could be observed on radial sections in both earlywood and latewood before natural weathering. The pit structures in the radial section appeared cracking after 12 days of natural weathering. The bordered pit is mainly composed of pectin and cellulose, which contains some phenolic substances [36,37]. With prolonged exposure, the phenolic substances were oxidized, and the pits cracked. Moreover, the deterioration also spread over the radial section of the tracheid walls, and the roughening of cell walls was also noticed.
L275-277: Absorption of UV-light by lignin on or near the wood surface causes the preferential degradation of lignin, followed by the degradation of hemicellulose and cellulose. These changes occur in wood vary greatly from 80μm to as much as 2540μm [59].
L164: ‘decay’ to ‘degradation’
Point 6:
Discussion
L263: Chemistry was not researched in this study – please remove this word.
Response 6:
L237-L239: The colour, and structural changes of wood surfaces during the first month of weathering were the most intuitive and accurate.
(remove the chemistry)
Point 7:
Final
Please, by reviewer opinion will be better choice to write in results only results of your work and all parts of discussion (for example L141-LL150; L152-LL164; L216-L223 and others….) give to the 4-th part of article – Discussion. Now there are more repeating parts in this article – reviewer have found 3 or 4 times the same sentence about photo-degradability of lignins… This way of presentation can improve quality of this interesting paper.
Response 7:
L144-L285: Result and discussion parts were adjusted, please refer to them.
Dear reviewer,
Thank you for your kindness.
Best regards.
Author Response File: Author Response.doc
Reviewer 4 Report
The authors need to decide which name of the object being studied is correct. Two different names are given in the text. Is it appropriate to use the term behavior in this context? There are repeated words, such as line 50, etc. What is the reason for choosing 15 trees at the age of 26-30 years? Table 1 is located above the first mention of Table 1 in the text. Table 1 shows the average and standard deviation? For what parameters (for what period) the average and deviation were calculated, and how many parameters were averaged (N= ?). You need to describe the methodology in more detail. Will the result change if you change the wood exposure period? Why is the summer period selected (only)?Author Response
Point 1: The authors need to decide which name of the object being studied is correct. Two different names are given in the text. Is it appropriate to use the term behavior in this context?
Response 1:
Thank you for your attention. Just use ‘Cunninghamia lanceolata’.
Point 2: There are repeated words, such as line 50, etc.
Response 2:
L46-L47: The study provides a basis for the rational utilization of the anti-weathering capability of Chinese fir.
Point 3: What is the reason for choosing 15 trees at the age of 26-30 years?
Response 3:
According to the previous literature , at the age of 26-30 years Chinese fir is a usable Chinese fir plantation. Density measurements alone used samples of about 15 trees, while other experiments used samples of about 5 trees for comparative studies
Point 4: Table 1 is located above the first mention of Table 1 in the text. Table 1 shows the average and standard deviation? For what parameters (for what period) the average and deviation were calculated, and how many parameters were averaged (N= ?). You need to describe the methodology in more detail.
Response 4:
L67-L80: Table 1 is located behind the first mention of Table 1 in the text.
Note: the parameters show the average and standard deviation during July and August 2017(N=30).
Natural weathering is done in these two months, excluding the time of indoor contrast experiments, the cumulative exposure time is 30 days.
Point 5: Will the result change if you change the wood exposure period? Why is the summer period selected (only)?
Response 5:
Refer to previous articles and select relatively significant environmental conditions. Summer has strong UV light and high temperatures and high humidity conditions.
Thank you very much for your suggestion. Other seasons will be tested separately in the future to improve the experiment.
Dear reviewer,
Thank you for your kindness.
Best regards.
Author Response File: Author Response.doc
Round 2
Reviewer 1 Report
The article has been modified, but has not changed in terms of its content.
There is a lack of reliable basics of the science of wood and the behavior of wood in the outdoor environment. This causes confusion between the concepts of heartwood and juvenile wood, which negatively affects the correct analysis and making conlusions.
The research description still shows deficiencies.
Author Response
Thank you very much for your suggestions.
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The difference of Chinese fir in radial direction.
Before this experiment, I verified the reliability of the data of the division of juvenile wood and mature wood conducted by Yin et al in 2011 on 30-year-old Chinese fir by microfiber length, density and other experiments. The radial variation of Chinese fir was consistent with the previous results.
Yin, Y.; Bian, M.; Song, K.; Xiao, F.; Xiaomei, J. Influence of Microfibril angle on within-tree variations in the Mechanical properties of chinese fir (Cunninghamia Lanceolata). IAWA J. 2011, 32, 431–442, doi: 10.1163/22941932-90000069.
Therefore, in this experiment, I used the samples at the position of 3-7 and 20-30 of the growth rings as the objects of radial comparison. These two positions are also the locations of the heartwood and sapwood, so the name of the professional term is confused. I'm really sorry about that. I have completed the replacement of juvenile wood and heartwood in the article, please refer to it.
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Selection of short-term natural weathering conditions in this experiment
The natural weathering method in this paper was tested according to the standard JIS K 5600-7-6. In the pre-experimental stage (April-May 2017), it was found that the structure of the wood surface changed significantly in a short period of time. After a month of natural weathering, the surface microstructure had been completely destroyed and the contrast experiment could not be completed. Therefore, one month is also selected as the cycle of the experiment in the formal experiment stage. Because of the different weathering degrees in different seasons, I will continue to compare the effects of weathering in different seasons, especially in winter.
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Structure and purpose of the article
The purpose of this study is to understand the variation in intrinsic weathering behaviour of Chinese fir. On the one hand, it can improve the utilization rate of wood. On the other hand, it can be targeted to study weathering pretreatment.
Thank you for your valuable comments on the article, which will be of great help to my future experiments.
Author Response File: Author Response.docx
