The Fine Root Distribution and Morphology of Mature White Poplar in Natural Temperate Riverside Forests under Periodically Flooded or Dry Hydrological Conditions

Round 1

Reviewer 1 Report

Dear authors,

The manuscript “Distribution and morphology of fine roots of mature white poplar in natural temperate riverside forests under various hydrological conditions” is well written and straightforward in the presentation and interpretation of the research and its results. I endorse to consider the potential publication of this work given that some minor remarks are addressed (see my comments in the pdf).

 

Comments for author File: Comments.pdf

Author Response

Please see the attachments.

Anna Frymark-Szymkowiak

Author Response File: Author Response.pdf

Reviewer 2 Report

In different hydrological conditions, the distribution and morphology of fine roots from mature white poplar forests are examined in this research. The analysis is unclear and the manuscript is not very well written. The result simply demonstrates the variations in poplar root-related indicators under various hydrological conditions; it does not identify the underlying reason of the variations. Additionally, the function of natural riverside ecosystems cannot be better understood due to the incomplete soil data analysis. The part on the sample collection said that soil samples were kept at -20°C until additional analysis, yet I am unable to observe any analysis. This paper doesn't offer creativity, the data analysis may need some work, and the findings don't adequately support the suggested conclusions. This is exciting research, but the authors should improve it.

Author Response

Anna Frymark-Szymkowiak                                                                                 21.12.2022.            

Department of Environmental Biology

Kazimierz Wielki University, Bydgoszcz

[email protected]

 

Dear Reviewer 2,

I would like to thank you very much for the opportunity to improve our manuscript in accordance with the recommendations.

Response to Reviewer 2 Comments:

 

In different hydrological conditions, the distribution and morphology of fine roots from mature white poplar forests are examined in this research. The analysis is unclear and the manuscript is not very well written. The result simply demonstrates the variations in poplar root-related indicators under various hydrological conditions; it does not identify the underlying reason of the variations. Additionally, the function of natural riverside ecosystems cannot be better understood due to the incomplete soil data analysis. The part on the sample collection said that soil samples were kept at -20°C until additional analysis, yet I am unable to observe any analysis. This paper doesn't offer creativity, the data analysis may need some work, and the findings don't adequately support the suggested conclusions. This is exciting research, but the authors should improve it.

 

Fine roots are, on the one hand, the largest reservoir of underground carbon on Earth, but on the other hand, due to their complexity, interconnectedness with the soil environment and the high rate of transformation, their study is still a challenge for researchers. Despite the wide range of available indices describing the parameters of fine roots, their interpretation possibilities are still limited, therefore performing specific tests does not always answer all questions.

The presented manuscript, as suggested by the reviewers, was supplemented with the results of soil tests (which were carried out for the described sites and included in the previous article - Frymark-Szymkowiak, Karliński 2021), which gives a more complete picture of the results obtained and their interpretation. I also modified the final conclusion, which now more fully refers to the results obtained.

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 3 Report

The results of this study are very interesting. But some improvements related to the methodology and data analysis should be added.

1. The samples in this study were collected in 2011-2014, it's been 10 years now. The timeliness and significance of data should be discussed.

2. All the reference are before 2013, recent research papers should be added.

3. The physicochemical properties of soil samples should be added. Does the physicochemical properties of soil could affect the distribution of fine roots?

4. in part 2.2: “the total numbers of samples were as follows: STA—107 samples, WK—73 samples, and OP—103 samples”, the detail samples numbers at different soil depth should be added.

5. The very important problem of this study was the representativeness of data. More statistical analysis should be added and discussed. Samples were selected at different site with different depth. The design principles and representativeness of sampling points should be discussed in detail to emphasize the representativeness of data. In addition, the design principles and representativeness of selected soil depth should be discussed also.

6. The introduction part should be improved based on the new recent literatures.

Author Response

Anna Frymark-Szymkowiak                                                                                 21.12.2022.            

Department of Environmental Biology

Kazimierz Wielki University, Bydgoszcz

[email protected]

 

Dear Reviewer 3,

I would like to thank you very much for the opportunity to improve our manuscript in accordance with the recommendations.

Response to Reviewer 3 Comments:

1. The samples in this study were collected in 2011-2014, it's been 10 years now. The timeliness and significance of data should be discussed.

 

In our opinion the results referring to root samples taken about 10 years ago don't lose their relevance, because the study sites were located in old-growth forests (>100 years at the time of root sampling). Forests in an old-growth stage are ecosystems that have attained full growth without significant interferences, showing high stability due to the significant self-regulatory potential (Forest Encyclopedia).  

According to literature reports, biomass production (above and belowground) in undisturb forest sites declines with age and reaches its maximum in the mature stand phase (80-100 years) (ie Pregitzer and Euskirchen 2004). On the other hand, in the study region (Lower Vistula Valley), a new dam is planned to be built on the river, which is likely to drastically change the water and environmental conditions. That is why it is so important to present and describe the functioning of certain elements of this ecosystem in still relatively natural conditions.

• Pregitzer K., Euskirchen E., 2004. Carbon cycling and storage in world forests: biome patterns related to forest age. Global Change Biology (2004) 10, 2052–2077, doi: 10.1111/j.1365-2486.2004.00866.x

2. All the reference are before 2013, recent research papers should be added.

Indeed, most of the references are from before 2013 (although there were also some citations from 2019 and 2020).  According to the suggestions recent papers new citations have been added.

• Ye, Z.; Wang, J.; Wang, W.; Zhang, T.; Li, J. Effects of root phenotypic changes on the deep rooting of Populus euphraticaseedlings under drought stresses. PeerJ. 2019, 7, e6513.
• Rodríguez, M.E.; Mozo, I.; Cortizo, S.; Cappa, E.P.; Luquez, V.M.C. Early rooting and flooding tolerance in cottings from a Populus deltoides full-sib family under greenhouse conditions. J. Bot. 2021, 51, 732-741.
• Frymark-Szymkowiak, A.; Karliński, L. Impacts of hydrological conditions on the activities of soil enzymes in temperate floodplain forest sites, Soil Res. 2022, 60, 637-647.
• Moresi, F.V.; Maesano, M.; Matteucci, G.; Romagnoli, M.; Sidle, R.C.; Mugnozza, G.S. Root Biomechanical Traits in a Montane Mediterranean Forest Watershed: Variations with Species Diversity and Soil Depth. Forests, 2019, 10, 341.

 

3. The physicochemical properties of soil samples should be added. Does the physicochemical properties of soil could affect the distribution of fine roots?

 

The analyzes of the physicochemical composition of the soil have already been carried out at the described sites and the results are presented in the published paper: Frymark-Szymkowiak and Karliński 2022 (Impacts of hydrological conditions on the activities of soil enzymes in temperate floodplain forest sites). In the current paper, this article is cited and discussed.

4. in part 2.2: “the total numbers of samples were as follows: STA—107 samples, WK—73 samples, and OP—103 samples”, the detail samples numbers at different soil depth should be added.

In the manuscript, I added the exact number of samples taken as suggested.

5. The very important problem of this study was the representativeness of data. More statistical analysis should be added and discussed. Samples were selected at different site with different depth. The design principles and representativeness of sampling points should be discussed in detail to emphasize the representativeness of data. In addition, the design principles and representativeness of selected soil depth should be discussed also.

In the completed work, I described in more detail the methodology of collecting soil-root samples, which confirms the representativeness of the collected samples. When planning the sampling scheme, a depth of 30 cm was decided, which is related to the most numerous  occurrence of fine roots in this layer (e.g. Steele et al. 1997, Root mass, net primary production and turnover in aspen, jack pine and black spruce forest in Saskatchewan and Manitoba, Canada.).  In the present research, all the forest  sites were characterized by approx. 30 cm of organic layer in the soil profile, which translates into the greatest abundance of fine roots.

6. The introduction part should be improved based on the new recent literatures.

More recent articles have been added in the introduction.

Please see the attachment.

                                                                                                                             

Author Response File: Author Response.docx

Reviewer 4 Report

This paper provides interesting results, and the research topic is within this journal's scope. The authors made an interesting contribution to the soil and root distribution field. However, in the present form, this paper has major problems. There are some comments that I ask the authors to address.

Here are a few suggestions and comments that hopefully may guide a restructuring of the paper:

General Comments:

1. Introduction and discussion do not provide sufficient background and include all relevant references. I found many related papers (I am not one of the authors of the following papers, and they are very useful for introduction, materials and methods, and discussion):

** https://doi.org/10.1007/s11104-022-05764-z

** https://doi.org/10.1016/j.catena.2022.106410

** https://doi.org/10.3390/f11030345

** https://doi.org/10.1007/s40333-018-0021-2

2. Conclusion section must be improved. The conclusion of a paper is where you wrap up your ideas and leave the reader with a strong final impression. Please, re-state the problem addressed in the paper, then summarize overall arguments or findings, and finally, suggest the key takeaways from the paper.

3. There is no line number in the paper, so it was very hard for me to review it. BTW, the last sentence of the abstract is too general; what is the implication of your study? add it.

4. Remove table 1 because it doesn't have a lot of information, and move it to text.

5. Section 2.2: What is the distance of the sampling point from tree trunks? Also, add some citations in section 2.2 (the abovementioned papers are useful).

 

Minor Comments:

- In the Materials and Methods (there is no line number, so...): The common name of Fraxinus excelsior is the  "European ash" (not "ash). Quercus robur is "common oak" (not "oak"). Ulmus minor is "European field elm" (not elm).

- Section 2.3: Add some citations here.

- Table 4: Add numbers of data to the table (as a footnote).

 

 

  

 

Author Response

Anna Frymark-Szymkowiak                                                                                 28.12.2022.            

Department of Environmental Biology

Kazimierz Wielki University, Bydgoszcz

[email protected]

 

Dear Reviewer 4,

I would like to thank you very much for the opportunity to improve our manuscript in accordance with the recommendations.

Response to Reviewer 4 Comments:

General Comments:

1. Introduction and discussion do not provide sufficient background and include all relevant references. I found many related papers (I am not one of the authors of the following papers, and they are very useful for introduction, materials and methods, and discussion):

Information about the stabilizing role of tree roots for river banks was added to the paper, and the introduction was supplemented with the characteristics of poplar as a tree with a wide environmental spectrum.  

2. Conclusion section must be improved. The conclusion of a paper is where you wrap up your ideas and leave the reader with a strong final impression. Please, re-state the problem addressed in the paper, then summarize overall arguments or findings, and finally, suggest the key takeaways from the paper.

The conclusion has been changed in accordance with the recommendations and mainly refers to the impact of various soil water conditions on the features of the poplar root system and also indicates the possible use of the trees of high adaptability in the renewal of vegetation in riverside areas.

3. There is no line number in the paper, so it was very hard for me to review it. BTW, the last sentence of the abstract is too general; what is the implication of your study? add it.

There are line numbers in the manuscript sent to the editor, but the program probably replaces and reformats the document. The last sentence of the introduction has been corrected as recommended.                               

4. Remove table 1 because it doesn't have a lot of information and move it to text.

As suggested, table 1 has been removed. I agree that she didn't bring any relevant information.                

5. Section 2.2: What is the distance of the sampling point from tree trunks? Also, add some citations in section 2.2 (the abovementioned papers are useful).

As suggested, the sampling methodology was detailed, including the distance of the samples from the tree trunk.                          

Minor Comments

In the Materials and Methods (there is no line number, so...): The common name of Fraxinus excelsior is the "European ash" (not "ash). Quercus robur is "common oak" (not "oak"). Ulmus minor is "European field elm" (not elm).

In the Materials and Methods section, the English names of trees have been corrected. Thank you very much for this suggestion.

Section 2.3: Add some citations here.

The described morphological features of small roots as well as programs enabling visual assessment of roots are commonly used (WinRHIZO Pro image-analysis system and related systems, as that used in our research).

E.g. (1) Arsenault JL, Pouleur S, Messier C, Guay R (1995).WinRHIZO, a root-measuring system with a uniqueoverlap correction method. Hortic. Sci., 30: 906.; (2) Domisch T., Finer L., Lehto T.,2002. Growth, carbohydrate and nutrient allocation of Scots pine seedlings after exposure to simulated low soil temperature in spring. Plant and Soil 246(1):75-86; (3) Rose L., Lobet G. 2019. Accuracy of image analysis tools for functional root traits: A comment on Delory et al. (2017) Methods in Ecology and Evolution, 10:702–711).

Table 4: Add numbers of data to the table (as a footnote).

As suggested, the number of attempts from each level has been added.

Please see the attachment.

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

Even though the authors put a lot of effort into improving their publication, the analysis of how the physicochemical properties of the soil affected the distribution of fine roots was still missing. This essay requires a significant boost.

Reviewer 3 Report

The authors try to response the comments in detail, but the key problem of the study is the main data of this study were collected 10 years ago. Even the authors responded that the studied stands are old-growth forests (>100 years at the time of root sampling), but the data discussed in are collected 10 years ago. Since the experiment was completed 10 years ago, why not write a paper at that time? The data maybe very interesting, but the timeliness of data must be discussed in detail. In addition, only 4 new references after 2013 was added is not enough, the importance of the study should be discussed in detail based on the revelated research, especially the new references in recent 10 years. 

Reviewer 4 Report

Dear authors,
Thank you for the improvement of the manuscript. I believe that this form of the manuscript better impacts readers from the international research area.