Emerging Microplastics Alter the Influences of Soil Animals on the Fungal Community Structure in Determining the Litter Decomposition of a Deciduous Tree

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Comments and suggestions
Authors: Xin Wang, Rumeng Ye, B. Larry Li, Kai Tian
Title: Emerging microplastics alter the influences of soil animals on 2 the fungal community structure in determining the litter de-3 composition of a deciduous tree
Manuscript number: forests-2876227
Summary of the manuscript:
The manuscript reports the results of a mesocosm experiment study. During the experiment, the authors investigate the role of the presence of earthworms (Eisenia fetida) and the springtails Folsomia candida (Collembola) in the decomposition processes, in conditions polluted with microplastics, and how these factors and conditions affect the structure and function of Lindera glauca litter microbes.
The manuscript is the original research paper of the authors. Nowadays, the role of soil organisms often comes to the fore, and the importance of their role in the ecosystem is proven more and more often. Therefore, any study that contributes to this field of science with new knowledge and research results is very important. The subject of the manuscript is interesting and current.
The theme of the manuscript’s scope fits the aims of the journal
The basic idea of the experiment was carried out precisely, and the study provided a large amount of high-quality data. In addition, the analyzes and their results are also significant because (as I mentioned above), research on soil-dwelling animals is quite rare. This is especially true given that the effect of microplastics on both soil and soil-related organisms is poorly known.

For this study, the authors used well-chosen and appropriate methods. The data are well
presented. What highlights the manuscript's importance is that the current practices and results contribute to sustainable land use.
I find the structure of the Abstract appropriate. Its length and scientific content are also acceptable. It summarizes the contents of the entire manuscript in a clear and concise way.
Line 32-33 the Keywords are appropriate, but those that appear in the title of the manuscript should definitely be replaced.
Introduction
This chapter supports and complements the research topic of the manuscript. Appropriate and timely references are built in the introduction chapter. In my opinion, it is a well-structured chapter, covers the essential areas of the entire topic of the manuscript.
In my opinion, soil organic matter is not really discussed in this chapter. It would be justified to deal with the role of organic materials and their decomposition, as the role of microorganisms and earthworms is significant. Furthermore, the organic materials broken down by microbes and earthworms are fundamental determinants of nutrient circulation, biological activity, and decomposition processes. The soil used during the test and its type should also be mentioned, mainly from a biological point of view.
This paragraph would contribute significantly to the development of the manuscript and to
making the discussed topic more rounded and comprehensive.
The end of the chapter adequately mentions the objective of the research. The goals are realistic and well-defined.
Methods
The methods chapter is appropriate and sufficiently detailed. Descriptions of the experimental conditions are complex and easily identifiable. The description of the research and treatments(in pot experiment) is well-worded. The description of the sampling and laboratory methods, as well as their support by literature references, is appropriate.

Line 120 – 134. In this chapter, the exact type and origin of the soil used during the experiment should be described, as well as the process of its preparation.

Line 120-122. In terms of the results and their comprehensibility and interpretability, it would also be important to detail the most important chemical-physical and biological properties of the soil used (pH, organic matter content, plasticity, etc.). These are determining factors that influence both the lower and higher living organisms of the soil.

Line 133. The chapter lacks a description of the soil enzyme testing method as well as the litter mass loss determination process. It would be important to briefly describe the principle and essence of the methods used.

Results

The presentation of the results is easy to understand and sufficiently detailed. These chapters are well-structured and properly constructed. These chapters provide detailed and perfectly summarize the new and novel results. It contains a number of useful experiences and findings.

Line 203-204. This is a very complex figure, difficult to understand and review. Especially considering that there is no unit of measure on the "y" axis of each graph.

Line 341. The inscriptions, units of measure and treatments on the "x and y" axes of Figure 6 cannot be read, so it is difficult to interpret the distinguishing key class-level species differences

The authors show the results in tabular and figure form and its show a lot of results. Evaluation of these results is appropriate and draws realistic conclusions in this and the next chapter (Discussion). On the other hand, it make useful and interesting findings that may be interested.

In my opinion, the many figures used are very clear and detailed. The figures and tables absolutely necessary to interpret the results. They are illustrative, practical and definitely needed to illustrate the results and the statements.

Discussion

The discussion also is very detailed, also well-structured, and properly constructed. It provides an adequate evaluation of the results obtained compared to similar research experiences. The authors know the related international research; therefore, the discussion is satisfactory.

Conclusions

The chapter summarizes and nicely sums up the essence of the manuscript. In addition, this chapter explains and justifies the data.

The tables are necessary and valuable for the presentation of the results.

The figure is illustrative, practical, and needed to illustrate the results and the statements.

The manuscript is suitable for publication after a few above-mentioned major revisions.

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

Emerging microplastics alter the influences of soil animals on the fungal community structure in determining the litter decomposition of a deciduous tree

A well written and interesting manuscript, thorough in its analysis.  Good to see that multiple diversity indices are included e.g. Shannon, Simpson and Chao1 indices.

minor comments:

Figures - check the font size as it is not consistent between figures and difficult to read for some e.g. Figure 6.  Also please define in full the litter treatments (L, LA....) in the figure legend so each figure can be read as a 'standalone' image

line 404 'White rot (Basidiomycota) plays an important role in lignin degradation [27], suggesting that soil animals, through selectivity, feed on Basidiomycota' / line 414 'Ophiocordyceps is mainly parasitic and an ascomycete that can cause the death of the host' - does the disturbance of the microbial community structure by soil animals or modifications to this in response to the presence of microplastics have any implications for tree health?

Any further work identified?

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

This article addresses the critical and topical issue of the role of microplastics in disrupting the soil biogeochemical cycle in deciduous forest ecosystems. Attempts are being made to determine how microplastics impact soil faunal communities and fungal assemblages in the soil organic horizon. For this purpose, a mesocosm-type experiment was carried out to analyse the decomposition rate of organic matter in different combinations, including with and without plastic (how the decomposition rate of organic matter is affected by soil organisms under these conditions). The work was designed correctly, and the expected standard results were obtained.

I have some specific comments on the paper:
1. the hypotheses and objectives are not written; they should be rewritten.
2. the authors write about soil animals throughout, and it is unclear which group they are referring to microfauna or mesofauna. This should be clearly explained.

3. Why have the soil properties not been tested in every case?

4. Please explain: "Soil animals could decrease the microbial decomposition of the litter"? Explain this in an ecological but not statistical way. I have doubts about this statement, and it contradicts generally known regularities. What came out in a laboratory experiment does not mean this is true in ecosystems. The statement that it came out that way from statistical analyses means nothing because it is just a programme.

5. Figure 5 is illegible

6. invertebrate grazing??? may share of? (line 418)

7. What type of soil was used? In the script, there is no information about it. It needs to be completed. 

8. The discussion about "Soil animals regulate the litter fungal community" needs to be supplemented and amended. There are inconsistencies in this.

9. Conclusions are best stated in bullet points and avoid repetition from the main text.

Comments on the Quality of English Language

Moderate editing of English language required

Author Response

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Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The authors corrected the manuscript accordingly. The previous version of the manuscript was corrected based on my previous review, the suggestions and comments were reviewed in detail, and the manuscript was amended accordingly. With these changes and additions, the manuscript is suitable for publication in the journal. I have no further suggestions or requests for amendments to the manuscript.

I definitely recommend the manuscript for publication.

 Thank you, excellent work.

I wish the authors much more success!

Reviewer 3 Report

Comments and Suggestions for Authors

The authors answered in all my questions. I'm satisfied.