Phytoplankton Communities’ Response to Thermal Stratification and Changing Environmental Conditions in a Deep-Water Reservoir: Stochastic and Deterministic Processes

Round 1

Reviewer 1 Report

Dear Authors,

I found the MS well-written, however, there are some minor comments and suggestions to improve the MS to make it fully suitable for publication.

Abstract

Incorporating Distinctive Keywords for Enhanced Discoverability will optimize the Visibility of Your Research for Easier Access and Wider Readership, as the phytoplankton community and community assembly is the almost the same.

Introduction

I recommend restructuring the Introduction to enhance readability and coherence. The first paragraph (L50-64) should focus primarily on phytoplankton, providing a comprehensive overview. The subsequent section (L65-85) can delve into environmental conditions and stratification, creating a logical flow. The last part, which includes a detailed description of the sampling location, may be better suited for a separate section, possibly the Materials and Methods.

Additionally, it is essential to explicitly state the main objectives of the study. Define your primary goals beyond describing the investigation. This will provide clarity on the research's purpose and direction. Consider incorporating a brief overview of relevant previous research in the field within the last paragraph, offering context and highlighting the study's contribution to the existing body of knowledge.

Materials and methods

Study area

Parts in L86-89 should go in the description of the study area.

L132 You should cite established standardized protocols on which your sampling was based.

L134 Which kind of Lugol solution did you use, acid or alkaline? Please add it to the description.

L137-138 Please provide how you count phytoplankton community to get biomass or abundance of your community. How did you get the total number of species, or how many species you have per L? Please provide a better explanation and which standard protocol you use.

It is not necessary to provide formulas for how you calculate alpha diversity indices, it is known how it goes.

Results:

I don't understand which environmental factors you showed in the PCA analysis? This Fig is not representative.

L269-270 Can you provide in the M&M section how you calculate the average density of phytoplankton?

I will suggest that Table 2 can go in the supplement files.

L301 Please check the currently accepted taxonomy name of Cyclotella meneghiniana. Also, when you are listing in the text and mentioning the species name for the first time in the text (your description) you should provide, also the name who is the author/who described the species.

In the description of Fig 4a, you should write what columns, whiskers, and dots are present in the graphical presentation.

In the Methods and Materials section, there is a need for additional information regarding the Non-Metric Multidimensional Scaling (NMDS) analysis. It's crucial to clarify the specific purpose of employing NMDS – what aspect of the data or research question does it aim to investigate? Furthermore, it's essential to specify the basis of the NMDS analysis. Was it conducted using Bray-Curtis similarity or dissimilarity? This information is crucial for transparency and replicability.

In Figure 4b, where NMDS plots are presented, it would be beneficial to mention the confidence level associated with the drawn ellipses. Providing this information gives readers insight into the statistical reliability of the clustering patterns observed in the plot.

Regarding the significant differences observed, it's important to clarify whether a statistical test was conducted to support these findings. Did you use Permanova or ANOVA to assess the significance of differences in the NMDS analysis? In summary, enhancing the clarity and detail in the Methods and Materials section regarding the NMDS analysis will contribute to a more comprehensive understanding of the applied methodology and the interpretation of results.

L335-337 I don't see a clear separation of phytoplankton community on NMDs, maybe for the surface, but the other two layers are mixed?

Fig 5 again you are missing the meaning of columns, whiskers, and dots on the graphical presentation.

Discussion

L437 Is the citation under number 11 the previous investigation of this reservoir in years from 2017 until 2019?

L446 I don't get which are the fig S1 and S3, you have only PCA fig in supplement file?

L466 You did not investigate the influence of rainfall on stochastic processes so you need to cite other research which has confirmed this statement.

L485 Missing space between words and a number of references; and dot in the end of the sentence.

The conclusion is just a summary of what you did, please provide a clear message from your research that is helpful for further investigations, why is so important? Not just a summary of your work.

Something with reference order is not good in the text firstly is appearing reference number 46 (L500) and then 45 (L512). And I cannot find reference number 45 before 46.

Author Response

Please see the attachment

Author Response File: Author Response.pdf

Reviewer 2 Report

Suggestions are in the text.

Comments for author File: Comments.pdf

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

Line 224 are you sure this is 13.94? On the chart, the highest points are above 15 RWCS/H. Please check all RWCS/H values.

Line 298 is this really a downward trend with increasing depth? in table 2 for Cyclotella and Flagilaria there was an increase in the degree of dominance in the team - please check.

Line 303-304 according to Table 2, the value of 0.980 in the bottom layer was achieved by Cyclotella sp., not C. meneghiniana. Please check.

Line 355, it can be considered that the Surface community is intermediate in nature between the other two communities

Figure 3 - maybe it's worth adding values to the charts. For me they are difficult to interpret.

Figure 3B - when it comes to the Surface and Thermocline layer, Cyanobacteria dominate in Autumn, Winter and Summer, but Chlorophyta dominate in spring. Cyanobacteria dominated in the bottom layer in autumn, but Bacillariophyta dominated in Winter, spring and summer (Dinophyta were also important in summer) - please check.

Line 371-390 - in Surface Bacillariophyta are not correlated with TOC, other taxa are correlated with DO, TOC and NH4-N,

Fig 7 - please analyze the results presented in these graphs again.

Discussion -No cited Fig. S3(A)

Author Response

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Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Dear authors,

After reviewing the revised content, I still noticed some minor errors that I would appreciate if you could correct.

Firstly, could you please rewrite the paragraph about the study area in a more fluent and cohesive manner, as there are several repetitions that could be addressed?

I did not ask for what is used Lugol solution, I asked which one did you use for your samples? Acid or alkaline, that needs to be clear in your MS, try to find Preservatives and methods for algal cell enumeration, and there you will see about Lugol solution!

Additionally, regarding the taxonomy section, have you verified the species names using databases like AlgaeBase or another reliable source? It's important to note that Cyclotella meneghiniana is considered synonymous with Stephanodiscus, so it's essential to determine which name is currently accepted. Also, when mentioning species names for the first time, it's unnecessary to include the year. For instance, instead of "Chlorella vulgaris" it should be "Chlorella vulgaris Beijerinck." And I do not see that you correct like that in your text?

Moreover, the descriptions of the figures should be reformatted into complete sentences following proper grammatical rules to enhance readability and comprehension.

Lastly, I believe the conclusion is overly lengthy. I suggest condensing it to convey a concise message about the study's findings and implications.

Author Response

Please see the attachment

Author Response File: Author Response.pdf