Evidence for the Use of Karst Tiankengs as Shelters: The Effect of Karst Tiankengs on Genetic Diversity and Population Differentiation in Manglietia aromatica

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Congratulations on your research and the way you have done this paper!

I have a few comments for you to improve the paper.

L 3. No full stop after the title of the paper.

L 123-127. It is important to state in the paper whether there are morphological or ecological differences between the 10 local populations of Manglietia aromatica studied.

L 372-374. The authors mention 3 stages of evolution of Tiankeng, depending on the origin and evolution of the flora. Some temporal landmarks would be welcome if they exist to give the reader a fuller picture of the issues addressed.

L 496-503. Although not necessarily related to the aims of the paper, it would be important for the authors to mention some of the possible measures for the conservation of genetic diversity in Manglietia aromatica with the development of Tiankeng.

It would not be uninteresting if the authors would also integrate an overview with karst tiankeng shelters into the paper.

Author Response

Dear Reviewer, Greeting from all of us. First of all, thank you very much for your contribution to this manuscript, your love is the greatest support for this research! After carefully considering your comments, we have made the following modifications. (1) The full stop after the title of this paper has been deleted. (2) In the section of ‘Plant materials’, the description of morphological differences between the populations of Manglietia aromatica was added. (3) Following your suggestion, we have added the evolutionary process of the tiankengs and the characteristics of the vegetation at different stages of evolution to the relevant part of the Discussion. (4) Combined with the evolution of tiankeng and the genetic characteristics of the Manglietia aromatica, we added relevant conservation measures and suggestions to the Discussion. (5) Following your suggestion, we have added an overview of the karst tiankeng, a plant refuge, to our Discussion. Thank you again for your contribution to this manuscript！ Best Regards！

Reviewer 2 Report

Comments and Suggestions for Authors

The adaptation of tree species results primarily from their current genetic variability. For this reason Great attention is paid to maintaining its widest possible spectrum, as well as monitoring threats to the population and genetic compositionIn practice, however, especially in the case of trees, very much so few species conservation strategies take into accounttheir genetic resources that determine their potential adaptive, which is of paramount importancefor the sustainability of the species. Therefore the assessmentadaptive variability should be inherentan element of developing a management strategyand protection of forest trees. Therefore, I picked up the manuscript with curiosity and interest. The manuscript is actually interesting, but summary and introduction are too long; also part of disscusion. What I miss is the lack of information on how many sediments were collected from the population. Without this, it is difficult to assess whether the authors' conclusions are correct.

Below suggestions:

The summary is too long and the use of abbreviations of population names makes it difficult to understand.

In keys word I propose added „Karst Tiankeng” in place of karst

I propose to explain the protection system present in China. Currently, the information provided in lines 63-64, 74  is not clear to the reader.

l.83- it's rather difficult to talk about population if there is only one individual

The introduction is too extensive. It seems that the last paragraph is not necessary to be so long, some of the information may be included in the discussion.

Table 1 is missing in the manuscript.

What are the red and black points in Fig. 1?

It seems that the titles of subsections 2.4, 2.5 and 2.6 can be combined into one

l.175- no needed dot at the end

Adjust the font in the "results" section title

The title in Figure 2 is not needed

L.203- this information should be in section material and methods

In Fig. 3c and 3d - it is not known which populations are IN and which are OUTSIDE

l.229-233 - are not understandable to a reader who does not know the geography of China

in tables 2 and 3 it is worth distinguishing which populations are in and out Tiankeng, then the description of the results will be more clear (especially l.240-2421, 248-250 and part “Gene flow among M. aromatica populations”), and will be also easier to read the discussions.

l.340-344 talk about the same thing, it can be written in one sentence

 

Author Response

Dear Reviewer,

Greeting from all of us.

  First of all, thank you very much for your contribution to this manuscript, your love is the greatest support for this study! After carefully considering your suggestions, we have made the following modifications.

1. Following your suggestion, we have modified the Abstract and the abbreviation of the populations was replaced by the full name.
2. We deleted and replaced the keywords that were repeated in the title of the manuscript.
3. In order to enable readers to better understand our sampling principles, we deleted the narratives about the existing system of protection in China that are mentioned in ‘Plant materials’ and replacing them with specific sampling methods.
4. The population of Manglietia aromatica is declining rapidly under the double impact of the ecological environment and human activities. Therefore, in order to collect as much sampling data as possible, we combined the populations containing only one individual with the populations close to the geographical location to study their genetic characteristics.
5. We simplify the Introduction and move some of the content into the Discussion.
6. In ‘Plant materials’, we supplemented 'Table 1. Sampling information of Manglietia aromatica'.
7. In ‘Plant materials’, we have added the note associated with the blue and orange points in Figure 1. The blue points represent the population outside the tiankeng and the orange points represent the population inside thetiankeng.
8. Following your suggestion, the titles of subsections 2.4, 2.5 and 2.6 have been combined into one.
9. The dot at the end has been deleted.
10. The font in the Results section title has been adjust.
11. The title in Figure 2 has been deleted.
12. The target paragraph has been moved to the ‘Plant materials’.
13. Fig.3c and Fig.3d show the mean value of genetic differentiation coefficient (F_ST) and nucleotide ambiguity (D_XY) between all populations outside and inside the tiankeng. Different colors represent the selected 19 chromosomes. And the note has been supplemented.
14. The detailed information on the location of the Manglietia aromatica population and the corresponding acronyms of the locations were completed in Table 1.
15. Following your suggestion, we have distinguished between populations inside and outside the tiankeng in Table 2, Table 3, Table 4, and Figure 4, and added the corresponding labels.
16. We have simplified the repeated sentences in the Discussion.

  Thank you again for your contribution to this manuscript！

Best Regards！

Reviewer 3 Report

Comments and Suggestions for Authors

The research is very interesting, however, there are several aspects that need to be improved, these are presented in the form of comments in the text and the most relevant ones are listed below.

 

Introduction:

Clearly specify the objective(s) of the work. Also, state the research hypotheses.

Key words:

Several of these words appear in the title. Replace them with keywords that do not appear in the title.

 

Methods:

- Only 35 samples were collected in 10 populations, which corresponds to 3.5 samples per population. The number of samples per population is not sufficient. Also, specify the sampling design in each population. For example, the distance between sampled plants and what proportion of the population was sampled.

- Table 1 is quoted. This is not in the text.

- Only adult individuals were sampled.  Justify why individuals of other developmental stages were not sampled. Justify why juvenile and young individuals were not included. Research on other plant species has shown differences in genetic diversity and structure between ages. Therefore, not including all ages may bias information on the genetic diversity of the population.

- Figure 1. The map is ideal for a national publication. However, remember that the journal is international, with an international readership. Therefore, locate the map of the Republic of China and the region where these populations are located. The idea is that non-national readers will be able to visually locate the location of the study towns. Indicate what is the difference between blue dots and orange dots. Indicate on the map, the populations inside and outside Tiankeng.

 

Results:

- Lines 203 to 204: This is not results. It corresponds to methods. Please specify this in methods and in figure 1.

- In several parts results are mixed with discussion. In the text, the parts that are part of the discussion are marked with "orange". Move those parts to discussion and complement it with implications.

- There are also parts that correspond to methods. These are marked in the text. Move to the corresponding section.

Discussion:

- Lines 402 to 405. The wording does not correspond to the discussion of the study. It precisely indicates the aspects that should be improved in this part of the discussion.

 

Conclusions:

- Improve, be concrete, avoid making it look like a discussion or another version of the abstract.

- Establish the conclusions in relation to the objective of the study, the research hypothesis (not stated) and the results obtained.

Comments for author File: Comments.pdf

Comments on the Quality of English Language

It just requires a better style revision.

Author Response

Dear Reviewer,

Greeting from all of us.

  First of all, thank you very much for your contribution to this manuscript, your love is the greatest support for this study! After carefully considering your comments and suggestions, we have made the following modifications.

Introduction

  In this section, we have added the purpose and hypothesis of the study in the last paragraph according to your suggestions.

Keywords

  According to your requirements, the words repeated in the title have been replaced.

Methods

  (1) Because of the small number of Manglietia aromatica and the serious phenomenon of single plant, we has collected as many samples as possible. In addition, the main purpose of this manuscript is to explore the influence of Tiankeng on the genetic characteristics of M. aromatica populations, focusing on two large groups distributed inside and outside Tiankeng. Your suggestion is the focus of our future research. We added the detailed information of the collection site and the number of samples collected (Table 1), and supple the sample collection rule.

  (2) In fact, we collected samples from all individuals that meet the sampling rules, including mature plants and seedlings. There was a typographical error here. Thank you for pointing this out.

  (3) In order to adapt to international readers, Figure 1 has been modified in this paper. The map of the People's Republic of China and the location of the counties studied have been added. In Figure 1, the orange and blue points were identified.

Result

  (1) Following your suggestion, we had transferred the target paragraph to the corresponding position in the Method.

  (2) For the part you have marked in orange, we have deleted or added the target paragraph to the Discussion.

Discussion

  The target paragraph has been deleted.

Conclusion

  We have modified the discussion to reflect the aims and research hypotheses according to your suggestions.

  Thank you again for your contribution to this manuscript！

Best Regards！

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

Congratulations to the authors for all the research work they have done!

Author Response

Dear Reviewer,

  Thank you so much for contributing to this study! Your insightful suggestions have been incredibly helpful in improving the scientificity and readability of this manuscript.

  Wish you a smooth and healthy work.

Reviewer 3 Report

Comments and Suggestions for Authors

Dear authors

The information presented in Table 1 (not presented in the first version of the manuscript) gives further insight into the research design. It would have been very appropriate to present Table 1 in the first version.

The number of samples per population (Table 1) is insufficient to meet the objectives.

First, we will have to review the ecological concept of “population”, and define the limits based on pollinating organisms and geographical barriers. It is possible that subpopulations are working and the points marked in Figure 1 are localities or sites within subpopulations.

According to the justification they offer. It is understood that in the sampled localities there are only relicts of the species; which denotes its serious status. I am surprised that it was only possible to collect two to four samples in some sites (it is understood that there are only that number of individuals, since there were no more to collect).

According to their justification that “the main objective of this manuscript is to explore the influence of Tiankeng on the genetic characteristics of M. aromatica populations, focusing on two large groups distributed inside and outside of Tiankeng.” The suggestion is that the research focuses on the analysis of these groups. A more congruent analysis proposal (and more robust because the number of samples would increase) would be: Subpopulation 1, localities within Tiankeng karst (LJ, SM, DC); subpopulation 2, localities around tiankeng karst (FY, FD, CW, MBL); subpopulation 3: localities far from Tiankeng karst (XB, CY, LH). Based on this, please present the RESEARCH HYPOTHESES and adapt the results, discussion and conclusions.

Comments on the Quality of English Language

Dear editor,

I revised the manuscript again “One of the evidence for karst tiankeng shelters: The effect of karst tiankeng on genetic diversity and population differentiation of Manglietia aromatica”. He told her that, in general, there were improvements.  However, the critical point is the number of samples for each “population”. This is already more evident with the presentation of table 1 in the manuscript (table 1 was not present in the first version).

According to table 1 (which was not sent in the previous version), the number of samples (2 to 4) obtained in various “populations” (ED, FY, CY-LH, DC, SM) is insufficient to comply with the stated objectives.

With the information provided in table 1, it is deduced that there is a problem in understanding the concept “population”. Due to the small number of samples, it is deduced that the points shown in Figure 1 are “sampling sites” or “localities”. The authors must review the ecological concept of population and define its limits (geographic barriers, pollinators, etc.). It is possible that only one population is being studied (at least those in and around the tiankeng karsts).

The authors justify the low number of samples by the phenomenon of one plant in the localities; Therefore, it is possible that only relicts of this species exist. The authors mention that “the main objective of this manuscript is to explore the influence of Tiankeng on the genetic characteristics of M. aromatica populations, focusing on two large groups distributed inside and outside of Tiankeng.” Therefore, the suggestion is that these groups be analyzed. A more congruent analysis proposal (and more robust because the number of samples would increase) would be: Subpopulation 1, localities within Tiankeng karst (LJ, SM, DC); subpopulation 2, localities around tiankeng karst (FY, FD, CW, MBL); subpopulation 3: localities far from Tiankeng karst (XB, CY, LH).

Based on the above, the authors must establish their research hypotheses (requested from the first review and not presented in the second version) and adapt their results, discussion and conclusions.

Author Response

Dear Reviewer,

  Thank you so much for contributing to this study! Your insightful suggestions have been incredibly helpful in improving the scientificity and readability of this manuscript. Based on your suggestions, we have reclassified the studied populations of M. aromatica according to the results of genetic structure. The first was the tiankeng subpopulation in southwest Guangxi, which included the DC, SM and LJ populations; the second was the subpopulation around the tiankengs in southwest Guangxi, which included the CW, MBL, FD, FY, LH and CY populations; the third was the Huanjiang subpopulation in the north-eastern part of Guangxi, which containd only the XB population and was far away from the first and second subpopulations. Based on this, the article's hypothesis, results, and conclusions have been modified.

  Thank you again for your contribution to this research！

Wish you a smooth and healthy work.