Impact of Environmental Conditions on Wood Anatomical Traits of Green Alder (Alnus alnobetula) at the Alpine Treeline

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

In the manuscript “Impact of environmental conditions on wood anatomical traits of green alder (Alnus alnobetula) at the alpine treeline” the authors e analyzed vessel characteristics (mean vessel area, MVA; vessel density, VD; and theoretic conductive area, TCA) and axial parenchyma abundance, as well as their distribution in the annual ring at a moist north-facing and a dry south-facing site at the alpine treeline on Mt. Patscherkofel (Central European Alps, Austria). This manuscript is well organized, and the drawn conclusions are coherent with the obtained results. The paper was well written!

 

Lines 25 – 27: Please, arrange the keywords alphabetically.

 

Lines 84 – 90: Please, explain in detail you hypothesis and predictions.

 

Line 121: Please, add the north symbol and the scale in the map.

 

Lines 171 – 173: I think that you should these important references as examples to support your sentence: “MVA, VD and TCA were calculated to gain insight on the plasticity of vessels formation throughout the growing period.”. I would like to suggest:

Romano, N., et al., (2016). Residual life and degradation assessment of wood elements used in soil bioengineering structures for slope protection. Ecological engineering, 90, 498-509.

Chambi-Legoas, R., et al., (2023). Potassium fertilization enhances xylem plasticity and growth recovery of Eucalyptus grandis trees in response to drastic changes in water availability. Forest Ecology and Management, 528, 120656.

 

Lines 186 – 191: Please, add more details on the statistical analysis,

 

Lines 193 – 288: The results are well written! Please, reduce the number of the figures.

 

 

Line 290 – 415: Well written!

Comments on the Quality of English Language

The paper is well written!

Author Response

Response to the reviewer´s comments (reviewer 1):

 

Manuscript ID: forests-2709558

Impact of environmental conditions on wood anatomical traits of green alder (Alnus alnobetula) at the alpine treeline

 

We would like to thank the reviewer for the careful revision of our manuscript and for the suggestions on improving it.

 

Comments to reviewer’s suggestions were marked with bullet points

 

Lines 25 – 27: Please, arrange the keywords alphabetically.

• As suggested, the keywords have been arranged alphabetically

Lines 84 – 90: Please, explain in detail your hypothesis and predictions.

• As suggested, the hypothesis and predictions have been explained in more detail

Line 121: Please, add the north symbol and the scale in the map.

• As suggested a north symbol has been added. A scale is already given in the bottom right corner of both maps

Lines 171 – 173: I think that you should these important references as examples to support your sentence: “MVA, VD and TCA were calculated to gain insight on the plasticity of vessels formation throughout the growing period.”. I would like to suggest:

Romano, N., et al., (2016). Residual life and degradation assessment of wood elements used in soil bioengineering structures for slope protection. Ecological engineering, 90, 498-509.

Chambi-Legoas, R., et al., (2023). Potassium fertilization enhances xylem plasticity and growth recovery of Eucalyptus grandis trees in response to drastic changes in water availability. Forest Ecology and Management, 528, 120656.

• We thank the reviewer for suggesting for suggesting these references. We have added the study by Chambi-Legoas et al. (2023) as requested. The study published by Romano et al. (2016) is related to practical application and therefore less relevant to the focus of our study

Lines 186 – 191: Please, add more details on the statistical analysis,

• As suggested more details have been added concerning statistical data analysis.

Lines 193 – 288: The results are well written! Please, reduce the number of the figures.

• We thank the reviewer for the suggestion. After careful reconsideration, we found all figures to be essential for presenting the results of our study.

Reviewer 2 Report

Comments and Suggestions for Authors

Dear Editor:

Dear editor, this paper investigated  the ecological factors impacting the wood anatomy of Alnus alnobetula at the alpine treeline. The authors present fundamental observations and interpretations of results at a high scientific level, emphasizing the significance of this research in the context of changing climatic conditions. This work represents a valuable contribution to the understanding of species' ecological adaptations in Alpine ecosystems, yet certain corrections are necessary.

Abstract:

The abstract should succinctly convey the fundamental aspects of the study - its objectives, methodology, key findings, and their significance in understanding the adaptation of Alnus alnobetula to the alpine ecotone.

Specify precisely how wood anatomical parameters (MVA, VD, TCA) changed and the significance of xylem parenchyma under variable environmental conditions at selected locations.

 

Keywords: I recommend to reduce keywords to 5.

 

Introduction:

Please add some sentences about why investigating the wood anatomical adaptations of Alnus alnobetula is crucial for understanding ecological changes, providing fundamental context, and the necessity of your research.

I would recommend indicating the influence of wood density as a key parameter that influences the wood anatomy.

Materials and Methods:

In general, this section is written well by the authors, however, they did not the measuring the wood density. As mentioned this factor influence directly on the other wood properties. I recommend adding this factor to explain the obtained results.

Results:

 Discuss specific numerical values and variations in wood anatomical characteristics between different locations, highlighting the statistical significance of each result.

Discussion:

Consider the broader implications of the results in the context of adaptation to environmental changes, particularly emphasizing how the findings contribute to understanding the adaptability of Alnus alnobetula at the alpine treeline.

Thoroughly compare and contrast your results with relevant research to confirm or expand knowledge about the adaptive strategies of this specific tree species.

Conclusion:

 

Suggest specific applications of your findings for monitoring ecological changes or managing alpine ecosystems.

Comments on the Quality of English Language

Minor editing of English language required

Author Response

Response to the reviewer´s comments (reviewer 2):

 

Manuscript ID: forests-2709558

Impact of environmental conditions on wood anatomical traits of green alder (Alnus alnobetula) at the alpine treeline

 

We would like to thank the reviewer for the careful revision of our manuscript and for the suggestions on improving it.

 

Comments to reviewer’s suggestions were marked with bullet points

 

Abstract:

The abstract should succinctly convey the fundamental aspects of the study - its objectives, methodology, key findings, and their significance in understanding the adaptation of Alnus alnobetula to the alpine ecotone.

Specify precisely how wood anatomical parameters (MVA, VD, TCA) changed and the significance of xylem parenchyma under variable environmental conditions at selected locations.

• We have tried to explain, how the wood anatomical parameters have changed in the necessary brevity; we assume that more details would be beyond the scope of an abstract.
• We agree that in a study focusing only on xylem parenchyma, a brief explanation would be necessary in the abstract. However, because our study addresses several questions, we are of the opinion that it is inappropriate to present a summary on single aspects and not on the others. On the other hand, it is beyond the scope of the abstract to give short introductions for all topics involved. Therefore, the significance of xylem parenchyma is explained in the introduction.

 

Keywords: I recommend to reduce keywords to 5.

• As suggested we reduced the number of keywords

 

Introduction:

Please add some sentences about why investigating the wood anatomical adaptations of Alnus alnobetula is crucial for understanding ecological changes, providing fundamental context, and the necessity of your research.

• As suggested a sentence has been added

I would recommend indicating the influence of wood density as a key parameter that influences the wood anatomy.

• There may be a misunderstanding, but in general the wood anatomy determines the wood density and not vice versa. No change was made in the text.

Materials and Methods:

In general, this section is written well by the authors, however, they did not the measuring the wood density. As mentioned this factor influence directly on the other wood properties. I recommend adding this factor to explain the obtained results.

• We agree with the reviewer, that wood density can give valuable insights. However, our study focused on changes in xylem anatomy including axial parenchyma cells.

 

Results:

Discuss specific numerical values and variations in wood anatomical characteristics between different locations, highlighting the statistical significance of each result.

• An additional table (Table 3 in the revised version) has been added to the text, giving the numerical values of the assessed parameters. All corresponding P-values are given in the Figures 3 and 5.

 

Discussion:

Consider the broader implications of the results in the context of adaptation to environmental changes, particularly emphasizing how the findings contribute to understanding the adaptability of Alnus alnobetula at the alpine treeline.

• As suggested we added a sentence to the discussion

Thoroughly compare and contrast your results with relevant research to confirm or expand knowledge about the adaptive strategies of this specific tree species.

• As suggested we have compared our results with relevant research

Conclusion:

Suggest specific applications of your findings for monitoring ecological changes or managing alpine ecosystems.

• We agree with the reviewer, that specific application for monitoring or ecosystem management would be very interesting. However, because our study focused on changes in xylem anatomy, it is not possible to make suggestions for monitoring or managing alpine ecosystems based on the results presented. Without more ecologically focused assessments, such an extrapolation of our data set would be highly questionable.

Reviewer 3 Report

Comments and Suggestions for Authors

The article is interesting, showing anatomical variations in the species Alnus alnobetula across two different sites. Attached are some observations to enhance the article.

Comments for author File: Comments.pdf

Author Response

Response to the reviewer´s comments (reviewer 3):

 

Manuscript ID: forests-2709558

Impact of environmental conditions on wood anatomical traits of green alder (Alnus alnobetula) at the alpine treeline

 

We would like to thank the reviewer for the careful revision of our manuscript and for the suggestions on improving it.

 

Comments to reviewer’s suggestions were marked with bullet points

 

 

Summary

The abstract is clearly written, emphasizing the A. alnobetula' significance and its

susceptibility to climate change. It outlines how environmental factors impact wood

anatomy, detailing vessel traits and axial parenchyma abundance, linking these anatomical

structures to environmental conditions. Simplifying sentence structure could enhance

readability, yet overall, it's a well-crafted and comprehensive abstract

 

• As suggested, we have simplified the sentences as much as possible.

 

Introduction

The introduction offers an overview of the species' significance, distribution across specific

Alpine regions, and the characteristics of its anatomical structures. It also presents the

research objectives. However, ther are some comments to increase the comprenhention:

 

Revise the paragraph located between lines 67 to 69 and focus on angiosperm species, as

In a strict sense, coniferous wood doesn't exhibit porosity (vessels).

 

• the paragraph has been revised as suggested

 

Lines 135 to 140: The environmental information collected during the July-Sept 2022

season is solely for reference? As per the established protocol, anatomical characteristics

were assessed over years 2011-2020. Therefore, the timing of collecting environmental

data could not be linked to the wood formation of the years investigated.

 

• Yes, the environmental data were collected as reference, to give insight on the environmental conditions at the sampling sites.

 

Regarding the 3 or 4 individuals collected from each site described on line 143, could the

diameter be included?

 

• As suggested, the mean diameter of stem discs was included.

 

 

Lines 159-160: The 70 rings that were analyzed to determine the variables came from

monitoring a range of 3 to 4 trees, please clarify.

 

• For clarity, the number of samples was added.

 

 

Materials and methods

The Materials and Methods section is written comprehensively, employing sub-sections

that enhance understanding of each aspect addressed. However, it would be of interest to

the article's readership to include, in addition to graphs, images showcasing the

anatomical structures from each site. This would demonstrate the measurement process

and highlight the differences between the sites.

 

• As suggested images of measured year rings from both sampling sites have been added to the manuscript as Figure S1.

 

It's important to mention the total number of vessels measured…

 

• As suggested the total number of vessels measured at the N-and the S-site was added.

 

Results

The climatic conditions during period July-Sept 2022 are presented in the article as results;

however, they could be considered as data and included in the methodology section as site

characteristics. Additionally, as mentioned earlier, these features should be approached

cautiously since they only represent the weather conditions of one year.

 

• As suggested the climate data from 2022 was moved from the results to the material and method section.

 

Please review the statement presented on Line 224 “Different letters indicate P > 0.05

among sites”. When different letters are used to indicate differences between groups, it's

because the significance level of 'P' is lower than the specified value, in this case, p< 0.05.

Please modify where necessary throughout the entire manuscript.

 

• As suggested > has been changed for < in the figure caption of the Figures 3,5 and 7

 

Line 227: Please clarify in the whole section that the data pertains to vessel area

distribution.

 

• As suggested vessel size has been changed to vessel area in the whole section.

 

Discussion

The discussion is lengthy and compares data from other articles to highlight similarities or

differences in the patterns of anatomical characteristics observed during the species'

growth.

 

Lines 361 to 366: If A. alnobetula exhibits a more semi-ring porous nature, the definition of

the 50% proportion for the first and second halves may seem somewhat arbitrary, as not

all years conform to this pattern.

 

• we agree with the reviewer, that there are differences between the years when it comes to timing of 50% of radial growth. However, our aim was to find an overall pattern in vessel and parenchyma distribution. After careful evaluations we concluded, that the differences in vessel distribution can be best presented by dividing the annual increment into two halves.

 

If variations occur within a year, this could prompt the demarcation between earlywood and latewood. The distinction in the earlywood and latewood proportion serves as a potentially valuable indicator of the impact of soil attributes and climatic conditions on growth.

Adding photographs of the measured structures would support the comments regarding

the classification of wood porosity and help establish the distinction between earlywood

and latewood at precisely the 50% mark of the growth ring.

 

• In alnobetula latewood usually comprises only one to three cell rows (see photographs added to the revised manuscript)

 

Conclusions

The writing of this section is clear, but the structure could be improved. The conclusions

could be presented into shorter sentences. For instance, separating ideas about vessel size

and density effects. Also, organizing the conclusions following the way that the hypothesis

and results were presented into the article.

 

• As suggested sentences have been shortened.

Reviewer 4 Report

Comments and Suggestions for Authors

 Impact of environmental conditions on wood anatomical traits of green alder (Alnus alnobetula) at the alpine treeline

[Forests] Manuscript ID: forests-2709558

Comments to the authors

I reviewed with great interest the manuscript entitled “Impact of environmental conditions on wood anatomical traits of green alder (Alnus alnobetula) at the alpine treeline” submitted to the journal Forests.

The topic is very interesting and well documented. The manuscript is well structured and easy to understand.

I only noticed minor errors. They are reported in the enclosed manuscript (pdf).

Good luck!...

Comments for author File: Comments.pdf

Comments on the Quality of English Language

Minor editing of English language required.

Author Response

Response to the reviewer´s comments (reviewer 4):

 

Manuscript ID: forests-2709558

Impact of environmental conditions on wood anatomical traits of green alder (Alnus alnobetula) at the alpine treeline

 

We would like to thank the reviewer for the careful revision of our manuscript and for the suggestions on improving it.

 

Comments to reviewer’s suggestions were marked with bullet points

 

• All minor corrections (like commas, missing spaces…) have been made and we will not list them here. In any case, we thank the reviewer for the very careful proofreading of our manuscript.
• Numbers of lines below refer to the original submitted (unrevised) manuscript

 

• line 25: as suggested the number of keywords has been reduced
• line 25: the country is mentioned in the Abstract.
• line 38: as suggested Alnus alnobetula has been changed to A. alnobetula throughout the manuscript.

• line 40: as suggested “&” has been changed to “and” throughout the text.
• line 62: the reference has been removed
• line 79: the reference has been corrected
• line 99: the reference has been added to the reference list
• Figure 1 : north arrows have been added to the figure
• line 146: the reference has been corrected
• line 146: Meinzer et al. 2001 has been added to the reference list
• line 175: We agree that the number of samples is limited. However, we would like to point out that data obtained were consistent and yielded statistically significant differences.

• line 202: the text has been changed as suggested
• line 276: as suggested, the sentence has been rephrased
• line 294: we wanted to discuss this issue as a problem of comparative studies.

We have better integrated the issue into the text.

• line 347: the paragraph has been rephrased to better emphasize the differences between our study and the references

• line 379: the reference has been corrected
• line 384: the reference has been corrected
• line 393: the references have been corrected