Land-Use Types Influence the Community Composition of Soil Mesofauna in the Coastal Zones of Bohai Bay, China

Round 1

Reviewer 1 Report

I enjoyed reading this manuscript by Zheng and colleagues about the soil mesofauna communities in coastal land-use types of Eastern China. The presentations and English language are good.

However, I found some main issues that should be discussed:

First, some terms you use seem not to be ideal, such as "land use patterns" and "original grasslands". That should be better "land-use types" or "land-use practices" and "natural grasslands", respectively (the grasslands seem to be natural, so no human influence, then they would be no land-use type but a natural habitat type).

Second, you have only one sampling date (period), a flaw that still many studies have to date but should be changed to several dates. You need to argue why this is enough (peak of vegetation? former studies showed that in this period most taxa can be found? etc.)

Last, you do not provide the dimensions of the soil fauna samples, and then you work with absolute numbers, which is out-to-date too nowadays, as this makes it impossible to compare different habitats and sample sizes on a global scale. (I strongly recommend using the average of the four replicates and then extrapolate to get the mean individuals per square metre [ind./m²] (plus minus the standard deviation).

Therefore, I recommend the study for publication after a moderate/Major revision by addressing these main and specific issues below.

TITLE:

L002: Add "Coastal Zones of the Bohai Sea (China)" or only "Coastal Zones of Eastern China" ?

ABSTRACT:

L016: I believe that "land-use patterns" is the correct version, and "land use" if you talk only about land use. Please check the whole text.
Further, is this the right term to use? I tried to search for it, but was not successful, but found "land-use practices" that might be more suitable. Or how about "land-use types"?

L026: "specific" appears as hyperlink, please check.

METHODS:

L081: Format "12.2 °C" with space

L082: Please provide also the soil classification you follow, FAO, WRB or Chinese Soil Taxonomy?

L083: I am a bit confused by the use of the term "original grasslands". Do you mean natural grasslands, so untouched by humans (like mentioned in Table 1)? Or are these pastures grazed by cattle or so?

L086: Unfortunately, the fact that you sampled only once is an issue to discuss. I suppose July is at the peak of the growing season (biomass and phylogenetic peak), right? But still you have only one sampling date (i.e., July), so you need to explain a bit better, why this is enough, and you think that one sampling point will depict most of the soil fauna communities.

L090: "at least 500 m apart" with space?

L094: It is not clear which dimensions the soil fauna samples had. Did you half the 20x20cm, so the sampled had 10x20cm? Or did you use the standard 5x5cm (or 5cm diameter round samples)? Please specify for replication.

L101: You talk about soil mesofauna but also include soil macrofauna (Coleoptera, Isopoda) and some atypical taxa (Brachycera, larvae or adults). Are you sure you want to keep the focus on soil mesofauna or better soil fauna as a whole?

L132: You should name the used package that you used to create the Venn diagram, like you mention the other used packages above.

RESULTS:

L144: It is okay to present the absolute numbers of found soil animals here. But, as the dimensions of the soil fauna samples are missing, comparisons to other habitats (also on a global scale) are impossible. So I strongly recommend averaging the four replicates per land-use type and then extrapolate them to get the individuals per square metre [ind./m²], a unit that is now used as a standard. (You will get large numbers, but that is the only way to compare different habitats and sample sizes.)

L160: "On the contrary" again as hyperlink?

L164: This paragraph lists basically all the data that can be found in Figure 2 already. I think it is too much, you should stick to the most prominent outcomes and could list the values in a table in the SuppData.

L164: Further, Figure 2 has too many colours and categories, it is impossible to read the very small lines. (I am not colour-blind, but you should also think about them, it is impossible to distinguish all the taxa). So one solution could be to put this with table in the SuppData and create a simpler version with the 5 most abundant taxa and then a "rest" category or so. Also, you could put taxa together at order level. Please think about it.

L194: Cicindelidae (or Cicindelinae) are not always seen as distinct family, so better list the identification keys that you used/rely on in the MM section.

L195: "There were four unique taxa observed in the wetlands " delete the second were

L218: "SM (%)"  and "CEC (cmol/kg)" , both with missing space

L235: "Figure 5 demonstrates the relationship...", delete The diagram of. Below the same: "Figure 5a indicates that..."

DISCUSSION:

L261: "This study demonstrates that ..." ?

L276: "which was reflected in the observation that ..." ?

L285: "balance and stability of ecosystem functioning" ?

L290: In the Discussion, if you are not sure or have proven things, better be catious about argumenting. "At the same time, the interactions of aquatic and terrestrial traits/influences may have promoted a higher number of soil mesofauna taxa." or so.

L310: What is a positive soil mesofauna taxa? Do you mean positively correlated? dominant?

L316: ... abundant taxa in Songnen grasslands in China." ?

L333: Are these adult Brachycera that are living in the soil? Or larvae? Generally you list also some soil macrofauna (Isopoda, Diptera), you may need to explain why you keep them in the analyses if you talk about soil mesofauna most of the time.

CONCLUSION:

L344: Here you could add one sentence summarizing the main outcomes in more detail, not only that the habitats differ. Maybe write that cotton fields had the lowest biodiversity (high disturbance) and natural habitats the highest biodiversity?

Author Response

Thank you for your recognition of our research and gives us a valuable chance to revise our manuscript. In the revised manuscript, we have addressed your comments point by point. Please see the attachment.

Author Response File: Author Response.docx

Reviewer 2 Report

Dear Authors and Editors

the manuscript titled "Land use patterns influence the community composition of soil meso-fauna in the coastal zones" is really very interesting and well argued.

The different parts are well structured and clearly developed. Study area, methods and results are well described and the discussion is clearly argued and with specific references to the literature on the subject.

Some formal suggestions and some small corrections are reported in the pdf uploaded on the site.

My opinion is that the work only requires some minor formal adjustment prior to publication.

Comments for author File: Comments.pdf

Author Response

Thank you for your recognition of our research and gives us a valuable chance to revise our manuscript. In the revised manuscript, we have addressed your comments point by point. Please see the attachment.

Author Response File: Author Response.docx

Reviewer 3 Report

The manuscript focuses on the differences in community composition of soil mesofauna belonging to different land use in coastal zones. The argument is very interesting and worthy of study, however patterns driving soil community structure depends on complex dynamics that are not well linked one to each other in the manuscript, both for deficiency in statistical models linking not only categorical but also numerical predictors with variables and for a lack in the interpretation of the results, with a discussion that did not deepen in the ecological information given by taxa. Moreover, there is a major point of concern, the extraction method, since 48h are a very short time for led soil dry and the arthropod fall into the preserving solution. For those reasons I suggest major revisions.

Specific suggestions:

Introduction:

L.38-39: explain better

L.69: highlight the importance of coastal ecosystems

Materials and methods:

L.93: How were the samples divided?

Table 1: if the statistical analysis were made by you, then the table should be presented in the results section

L.103: 48h is not enough time to induce all the arthropods to run away from the heating source and let them cross the soil sample to fall into the preservative solution. Moreover, what heat source did you use? And the preservative solution was made of 75% alcohol and the other 25% of…?

L.128: Did you transform the data (e.g. square-root) to minimize the influence of the most abundant taxa?

L.134: specify the variables (both y and x). Moreover, where are reported the results of those models? In the results section I only see Anova and LSD, but not glm. A well design model would be useful to understand if taxa variations are related to intrinsic characteristics of the land use, to environmental factors, or both. E.g. Isotomidae could respond more to N variations than to land use

L.138: Did you test for the assumptions?

Results:

L.148-150: Data are presented in the table yet, you don’t need to repeat them in the text

Table 2: Is mean and standard deviation, or standard error? Why the deviation/error is not presented for richness and taxa parameters?

L.154: The significance is not indicated in the table

L.157-158: Not really, it doesn’t give any information about the composition, only about the presence of dominant groups

L.166: Here, and then, the Collembola family is Onychiuridae, not Onychiruidae

L.210: I suggest deleting “It was obvious that”, because is more a discussion then a result presentation

Table 3: Why LSD test was never cited in the Statistical analysis section?

L.223-226: p-values are already indicated in the table, you don’t need to repeat them in the text

Table 4: This table seems a repetition of table 3, but less informative, since it lack of a post-hoc (I suggest to present first Anova results, and then LSD, which is a post-hoc)

L.273-274: explain better, it is confused

L.308-309: Why you say that it is confirmed? Moreover, you just wrote that CEC negatively correlated with cotton fields, thus indicating low fertility, so how can Isotomidae indicate the contrary?

L.312: explain “life history and adaptability”

L.320-322: more likely they respond to the absence of anthropic disturbance in the coast, as seen in Table 1. Otherwise, your suggestion needs support from bibliography

Author Response

Thank you for your recognition of our research and gives us a valuable chance to revise our manuscript. In the revised manuscript, we have addressed your comments point by point. Please see the attachment.

Author Response File: Author Response.docx

Reviewer 4 Report

See attached file.

Comments for author File: Comments.pdf

Author Response

Thank you for your recognition of our research and gives us a valuable chance to revise our manuscript. In the revised manuscript, we have addressed your comments point by point. Please see the attachment.

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

In this second round, I have found only minor issues, good job in implementing the comments!

L104: space before [20]

L196: Do use the the package VennDiagram? then please delete space after " and write "VennDiagram"

L341: As commented in the first review round, your focus is on soil meso-fauna, but here you speak of soil macro-fauna groups. Below you find two globally accepted papers with a good separation of what is meso and what macrofauna. You can focus on mesofauna, but please state correctly when talking about macrofauna.
https://www.globalsoilbiodiversity.org/atlas-chapter-2 and here https://onlinelibrary.wiley.com/doi/10.1111/brv.12832

L765: "Brachycera inhabit aquatic environments, ..." ?

Author Response

Thank you for your recognition of our research and gives us a valuable chance to revise our manuscript. In the revised manuscript, we have addressed your comments point by point. Please see the attachment.

Author Response File: Author Response.docx

Reviewer 3 Report

Thank you for improving and correcting the manuscript. I think that now can be published without further corrections.

Author Response

Thank you for your recognition of our research and we are very grateful to your work for our manuscript.

Author Response File: Author Response.docx