Relationships between Xylem Transport, Anatomical, and Mechanical Traits at Organ Level of Two Cupressaceae Species
Round 1
Reviewer 1 Report
Abstract:
Line 8: can be more grave as they are not used to (please revise this sentence and if possible use alternative wordings of more grave).
Line 10: Xylem structures and functions of these species (which species?; would be better to write “of species growing in the humid region”).
Line 11: Any specific reasons, why the authors targeted three Taxodiaceae species grown in a well-watered common garden? Why not in the abandoned habitats
Line 14: replace then with Likewise we analyzed.
Line 15: Please remove numbering in the results
Line 19: S. sempervirens (Write full names of the plants here), also delete significantly.
Line 20: The correlation coefficient between Ttob and root P50 was −0.51 in T. distichum var. imbricatum, and between WD and T. distichum branch P50, it was −0.4. (What does it indicate? Please interpret the correlation coefficient results (r-value) over here).
Line 23: and this led to (revise as which led to)
Introduction: The introduction is too lengthy and needs to be refined by removing unnecessary stuff and too many references. Some suggestions and questions are given below for improvement.
Line 32: previous studies have suggested (please do not starts from such wording, use an appropriate one and revise it accordingly.
Line 35: it has been reported…….safety margins (provide a reference here).
Line 36: plants in arid areas, forest species in humid areas (quite confusing may be revised as plants in arid, and forest species in humid areas).
Line 38: areas replaced with regions
Line 38-45: there are too many references, please cite only the latest and valid references.
Line 45: in this sense, a comprehensive study focusing on plant xylem (revise as please)
Line 51: the Ks directly reflect species hydraulic efficiency (delete former, most, of a species, latter, and of a species).
Line 53: The vulnerability curve for xylem describes the percentage loss in hydraulic conductivity under different water potential gradients (Cochard et al. 2013). This sentence doesn’t make sense here and has no connection with the prior one.
Line 58: Cavitation resistance varies greatly among different taxa, even among related species growing under the same conditions (which same condition, climatic or soil??).
Line 59-61: what is the difference between lines 46-47 and 59-61, please avoid repetition.
Line 65-74: this paragraph seems to be the results rather than the introduction; also there are old references like Sperry 2004, Carlquist (1982), and Tyree et al. (1994). Similarly para in 78-82 is more likely to be fit in the discussion.
Line 90: I don’t think Carlquist (1982) and Zimmermann (1983) are required here. Also, delete old references like Hacke et al. (2001) from this para.
Line 111:118: shift this to the discussion section, it doesn’t make sense here and also the introduction is too lengthy.
Line 132: write Taxodiaceae plants
Line 137: should be a question mark (?) at the end.
Materials and methods
Line 144: Please provide a valid reference right after the subtropical zone.
Line 145-150: please split the sentence into two for clarity.
Line 152: is too short, please expand it.
Line 154: here the author mentioned that the plants were selected with similar heights. However, the height given in Table 1 varies greatly (17-23).
Line 156: which southern part? Why did the authors give the time 8 to 10 in the morning (I don’t think it’s essential)?
Line 158: could be used or were used?
Line 160: the authors have collected roots at a depth of 10-20 cm while the root length was 20-40 cm. Why not the authors collected the samples from the entire length with which the roots penetrate deeper into soil layers?
Line 164: The table caption may be revised as “Habitat and structural or densitometric characteristics of the three Taxodiaceae plants/species”.
Line 165: why did the authors place the collected samples in the dark?
Line 173-177. Please rephrase the paragraph as there are several grammatical mistakes, also some values enclosed in the brackets need to be properly placed.
Line 184: then (delete please and start from The).
Line 196 and 201: short sentences, please expand them.
Line 202-2010: please split the para into two or three sentences.
Line 212: Please cross-check the sentence with 194, its repetition.
Line 216: the thickness-to-span ratio was computed using the formula …….
Line 218: Two-way ANOVA, correlation analysis for the structural and functional traits, and chart construction were all undertaken using R (version 3.5.3; R Core Team 2019). This sentence is incomplete. Why two-way Anova and correlation were used, needs to be mentioned. Also need to mention that box whisker plots were constructed for seeking variations in different properties of branches and roots of the three species.
The author also needs to describe why the most commonly used constrained ordination technique (like Redundancy Analysis, RDA), and why not the unconstrained ordination technique was used. I believed unconstrained ordination will give better results and interpretation in this study. In addition, this, the RDA-biplot as mentioned in the results (Figure 8A, B, and C) is not given.
Results and Discussion:
Line 231-235: of the three species; respectively, for the three species, the (delete please).
Why do the authors convert P50 values from negative to positive? (See caption of Figure 1). Secondly, the results section is full of values, which need to provide in a Table. The adjusted R2 values given in the results must be with r2 (a statistical rule it must be written as small r) and similarly the P-values with small p).
Line 303: structural traits (delete traits please).
Line 328-332: Please do not mention figures in the discussion as all these are given in the results. Also, the first para of the discussion seems to be the conclusion. Reference Philip (1996) delete or either replace with the latest one.
Line 372: increasing number of studies (delete increasing); Line 374: likewise, our results showed that
Line 404: The conclusion is almost a repetition of the earlier part of the results and discussion (please revise it). Also cross-check all the references and arrange it according to the journal format
Author Response
Please see the attachment.
Author Response File: 
Author Response.docx
Reviewer 2 Report
According to Brunsfeld et al. 1994 (doi:10.2307/2419600), Gadek et al. 2000 (doi:10.2307/2657004), Kusumi et al. 2000 (doi:10.2307/2656874), and Quinn et al. 2002 (doi:10.2307/4110984), the former family Taxodiaceae is included into the family Cupressaceae and within it, it represents a subfamily Taxodioideae. Therefore, I would suggest placing in the main title: "...of three Taxodioideae species (Cupressaceae)", but the genus Sequoia is used in the present study, which falls within the subfamily Sequoioideae. Therefore, the only way to correctly use the up-to-date plant taxonomy is to write just "...of three Cupressaceae species" and to use this family elsewhere in the text instead of Taxodiaceae. But again, three species were not studied but only two. The second species was represented with two taxa: one of specified variety and one of unknown variety, but they surely cannot present two distinct species. In my final recommendation, I suggest mentioning two instead of three species throughout the text.
Other suggestions and remarks are provided in the file attached.
Comments for author File: 
Comments.pdf
Author Response
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Author Response File: Author Response.docx
Reviewer 3 Report
The manuscript entitled Relationships among xylem transport, anatomical, and mechanical traits at organ level of three Taxodiaceae species presents interestingly the interrelationships of the traits responsible for the various systems in the tree.
The paper is clearly written and contains interesting graphic design. This is rather initial form of research relating to the Taxodiaceae species with a proposal to deepen the research to include other parts of the plants than just those studied in the work. For this reason, it is worth building a solid foundation for potential future work. It is worth paying more attention to this work to refine it better.
Critique and suggestions
Methods
The basic assumption of the study presented in the paper should be the constancy of the growth conditions of all trees. Probably there is some intra-species variability that has not been studied. To eliminate intra-species variability, it is necessary to ensure that all other conditions are the same for all trees, or at least are well described.
What environment did the trees come from, dry, humid? What was the condition, type of soil? Did the trees grow in the same stand or in different stands? If in different ones, were the environmental conditions in those stands the same?
li. 213-216
It is not entirely clear which density of wood was determined? Different types of density can be mentioned depending on the moisture content of the wood, this one depends on the mass and volume. Did the calculation assume the mass of dry wood at 0% moisture content (oven-dry wood)? It is not clear from the description how long the samples were dried and whether all the water was removed? How exactly was the volume of the wood measured? Wood swells in the hygroscopic range and shows different volumes. For what moisture content of the wood was the volume determined?
Nomenclature
“Mechanical strength” is used for testing mechanical wood properties, e.g. bending strength [MPa], compression strength[MPa]. If the thickness-to-span ratio handles partially mechanical properties, wood density belongs to physical properties and is only indirectly related to mechanics. Rather, physical and mechanical properties should be treated separately or use term mechanical support (not “strength”).
ll. 317-326 in the paragraph text is related to Fig. 8 which does not exist, probably it is about Fig. 7.
Statistical analysis
A two-way anova analysis was used. This analysis is used to show interactions in two variables (how two independent variables, in combination, affect a dependent variable). Why were these interactions not shown? Has there been any interaction?
What post-hoc tests were used to determine groups (a, b, c, d) within the population? Tukey? NIR?
RDA analysis was used correctly for the multivariate system, but it is not a substitute for two-way-anova, the results of which should also be reported.
What type of correlation coefficient was used to determine correlations between the xylem structural traits and functional traits (Fig. 6). Since normality was tested, it is likely that Pearson was used, but the paper does not mention this.
In the text there is a description of the coefficient of determination (R2), the value of which refers to Fig. 6. (ll. 293-316). There are completely different values in Fig. 6, and it is definitely not the coefficient of determination (R2), since its value cannot be negative (except adjusted R-Squared). Fig. 6 also does not show a P-value (quoted next to R2), but only values of alpha. This part of the work is unclear and should be corrected.
What do the *, ** in Figure 7 mean?
l. 134 …of three plant were compared… probably “species” not “plants”, (see l. 153 - We selected 10 to 15 plants of each species)
l. 226: The citation of Liu et al. 2016 in references is missing, unless you mean Liu et al. 2018 (l. 496)
l. 41 Yan et al. 2005; citation is missing in references
l.219 R Core Team; citation missing in references, please use version visible in your computer after typing citation() in your R console e.g.
> citation()
To cite R in publications use:
R Core Team (2021). R: A language and environment for
statistical computing. R Foundation for Statistical
Computing, Vienna, Austria. URL.
https://www.R-project.org/.
Author Response
Please see the attachment
Author Response File: Author Response.docx
Round 2
Reviewer 3 Report
All my comments were taken into account by the authors. Particularly important was the addition of information about the analyses in the supplements. I believe the current version is suitable for further editing.
Please replace the phrase „the dry weight (M, g) was weighed” with „dry wood was weighted” or „dry weight was measured. (l. 195)
