Centennial Lake Environmental Evolution Reflected by Diatoms in Yilong Lake, Yunnan Province, China

Round 1

Reviewer 1 Report

In the paper entitled “Centennial lake environmental evolution reflected by diatoms in Yilong Lake, Yunnan Province, China”, the authors have attempted to explain the object in detail, and they brought information in this regard. However, some improvements and clarifications in the manuscript as below are necessary to be applied. 

-          Provided research methodology including instrumental analyses, data gathering, and etc. must be described well.

-          The content variations in each sample (throughout thickness) are necessary to described in detail.

-          Sampling pattern/mapping is recommended to display in detail.

-          In part 4, page 6, the reactions involved in pH variations, and diatom content changes is recommended to provide.

-          More details in especially for recent years are required in conclusions.

Author Response

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Author Response File: Author Response.docx

Reviewer 2 Report

Line 85 : abundant

Line 131 : And there is no correlation between 130 two diatom species if the angle is 90°. 3). Also, the correlations between the vectors and 131 axis are the same as above.

Line 195 : years drought that completely dried up Yilong Lake. they can correspond to the diatom 195 zones of 31 cm and 7-9 cm respectively.

Author Response

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Author Response File: Author Response.docx

Reviewer 3 Report

-  The abstract should state briefly the purpose of the research, the principal results and major conclusions. An abstract is often presented separately from the article, so it must be able to stand alone.

- Page 6: the following paragraph is unclear, so please reorganize that:

“A.exigua, N. menisculus, and N. viridula are distributed in the negative position of axis 2. A. exigua is more common in eutrophic polluted waters [50]. N. menisculus is commonly found in freshwaters such as swamps, lakes, and rivers and endures organic pollution with high tolerance to inorganic eutrophication [51]. N. viridula exists in waters with high nitrogen and phosphorus [40] and occurs in eutrophic rivers in China [52].”

- The quality of figure 1 is not acceptable. I would ask you to use the original source of figure 1.

- All symbols and parameters should be defined, please check.

- The major defect of this study is the debate or Argument is not clear stated in the introduction session. Hence, the contribution is weak in this manuscript. I would suggest the author to enhance your theoretical discussion and arrives your debate or argument.

- Much more explanations and interpretations must be added for the Results, which are not enough.

- It is suggested to add articles entitled “Abujraiban & Assaf. Effect of Strategic Planning of Human Resources in Management Performance” and “J. Carvalho. Modelling (Social) Intra/Entrepreneurship Process” to the literature review.

- More suitable title should be selected for the figure 5 instead of “pH value and eutrophication curves compared with the measured data in Yilong…..”.

- Methods section determines the results. Kindly focus on three basic elements of the methods section.

a. How the study was designed?

b. How the study was carried out?

c. How the data were analyzed?

- Please make sure your conclusions' section underscore the scientific value added of your paper, and/or the applicability of your findings/results, as indicated previously. Please revise your conclusion part into more details. Basically, you should enhance your contributions, limitations, underscore the scientific value added of your paper, and/or the applicability of your findings/results and future study in this session.

Author Response

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Reviewer 4 Report

While the number and biodiversity of algae in aquatic ecosystems provide information about the efficiency of the aquatic environment, some algae species, which are pollution indicators, are also important criteria for determining the degree of environmental pollution and eutrophication in these environments. In the study, the identification, counting and statistics of the samples collected from the sediments in different layers of the lake were made. The variation of species diversity in diatoms in the lake between years has been determined. The study also explored the evolution of lakes and what needs to be done in the future. However, some lacks were identified in the study. 

1.     The productivity level of a lake; chlorophyll-a concentrations are determined according to OECD (1982) based on Secchi disc and phosphorus values. However, the authors never mentioned OECD values. It is also used in various diatom indices. In order to increase the quality of this study, it will be more meaningful to interpret it by comparing it with diatom index.

2.     The author stated that a phase contrast microscope was used for enumeration of diatoms. Morphological features are mostly used in the diagnosis of diatoms due to their siliceous structure, and frustule differences are very important. So my question is: are there images of these diatoms? If so, why was it not included in the article? It can even be included in scanning electron images in terms of visuality. Was the counting manually or was a program used? (such as Image J)

3.     3. In Figure 5, the author expressed that “pH value and eutrophication curves compared with the measured data in Yilong Lake.a: pH value, b: eutrophication, c, d, e: TN, TP, and Chla between 1993 and 2020” but looking at the figure, the pH and eutrophication date back to 1938. Therefore, there is a confusion of meaning. this explanatory text should be rearranged.

Author Response

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Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

The present form is acceptable for publication. 

Reviewer 3 Report

The article has been revised very well, so I would suggest to accept in its present form.