Review Reports

Round 1

Reviewer 1 Report

Reviewer 1 Diversity report

The reviewed paper presented very interesting data about contribution of diplopod Rossiulus kessleri in the distribution of algae in terrestrial ecosystems. The interaction of animals and algae in the soil has been studied extremely insufficiently, so the relevance of the article is beyond doubt. The conclusions are supported by the results and discussion. Manuscript is clear for understanding.  The authors analyzed the modern literature on the researched topic. But before the publication, the authors should make some corrections.  

Remarks to the authors.

1. I think, that it is necessary to give more detailed description of Rossiulus kessleri biology, especially their digestive system. Readers would be interested to know which enzymes are released during the digestion of algae.
2. You can write the author name of Rossiulus kessleri when first mentioned on line 70, and remove it on the line 123.
3. Latin names should be in italics.
4. In Table 2 in the first column it is better to delete the words Division and Class.
5. The quality of the Figure 2C is worse than other pictures. You can reduce the size of this image.

Comments for author File: Comments.pdf

Author Response

Dear Colleague,

We thank to you for your detailed analysis of our work. All comments were taken into account and all needed changes to the article were made.

1. We gave detailed description of Rossiulus kessleri biology;
2. Made latin names Italic;
3. Did correction of Table 2;
4. Did correction of Figure 2C.

Author Response File: Author Response.pdf

Reviewer 2 Report

Please see the attached document for a more complete and detailed review. 

I immediately found the subject of this paper very interesting. While narrow in scope, it is rare to see assessment of endozoochory of algal species, or examination of dispersal vectors for terrestrial algae in general. I think that the paper could be strengthened greatly by starting the intro with a discussion of endozoochory and how it has contributed to distributional patterns, particularly if you can discuss broad and fine scale patterns. Then, focus in on finescale patterns of terrestrial algae, for which I expect there to be very little literature, which makes your paper all the more interesting! In general, much more detail is needed for the methods and why the study organism and sites were selected; often, the authors provide a reference and/or vague description without even a brief summary of what was done. Your methods should be reproducible as a standalone study without any guesswork or reference. It is confusing why the two parks were used – one was found to not even be home to millipedes, thus, it would make more sense to revise the manuscript to only discuss the one park from which data were collected. I found the tables to be an ineffective way to communicate the results of the study, I believe a figure could be crafted to more elegantly demonstrate the differences in algal assemblages among the leaf litter, millipede body surface, and millipede feces. The aspect of the manuscript that needs the most work is the English and composition. At times it was clear that different authors contributed to manuscript, as it was easy to detect when the voice and prose changed, and grammatical accuracy either increased or decreased. I have provided some edits through the intro and methods, but it came exhaustive to provide the level of edits needed and I believe this level of editing is beyond the scope of a reviewer.

Comments for author File: Comments.pdf

Author Response

Dear Colleague,

Thank you for your detailed analysis of our work. We took into account your comments and made the all needed changes to the article.

1. All jargons were checked with Dictionaries, and replaced by appropriate terms;
2. English style was improved;
3. In the introduction more background information was given;
4. Detailed description of methods was given;
5. Biology of Rossiulus kessleri was given more widely;
6. More detailed description of parks, their differences were given;
7. Conclusion was revised and improved;
8. Tables and Figures were checked and improved.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

The MS was corrected according to my suggestions. I don’t like only one thing: in Figure 1 the pictures composed unevenly. Photos should be placed strictly one under the other and at the same distance. Please, try to correct it. 

Comments for author File: Comments.pdf

Author Response

Dear Colleague,

thank you for your edits and comments on our paper.

Best regards, O. Pakhomov, A. Pokhylenko, I. Maltseva, Y. Kulbachko.

Author Response File: Author Response.docx

Reviewer 2 Report

Please find specific comments attached.

Comments for author File: Comments.pdf

Author Response

Response to Reviewer Comments

Dear Colleague,

We appreciate your edits and thank you for your valuable comments about our article.

 

 

Point 1: There are still many issues with language, grammar, and jargon (e.g., edaphophilic, for which I cannot even find a definition, but regardless, is clearly not a commonly used term), as well as typos in general (numerous typos, misspellings, failure to italicize species names, etc.). Terms phytocoenoses, algocoenoses and edaphophilic were replaced by appropriate ones;

Response 1: Extensive editing of English language and style was conducted. The italics for all species names were revised. Probably, the modification/disappearance of italics (as a word’s merging in the text) is due to different MSWord editions.

 

Point 2: Similarly, I do not understand the inclusion of Table 1; the intro and methods clearly state that R. kessleri was selected as the model organism for the study.

Response 2: Table 1 was excluded.

 

Point 3: Are there common names for the tree species provided?

Response 3: Common names for the tree species were provided both in the abstract and methods sections.

 

Point 4: The level of detailed information about the experimental design and data collection methods is overkill for the abstract. Use full species names for example algal species.

Response 4: Abstract section was rewritten.

 

Point 5: I am confused by the specific use of the term diaspores in the context of this study, as entire organisms are being consumed and dispersed. I think any specification or reference to seeds or diaspores is unnecessary, particularly when you begin to discuss algal communities, as you are primarily just discussing the phenomena of zoochory.

 

Response 5: The term “diaspore” was revealed and detailed to disclose the term “zoochory” to a wide audience.

 

Point 6: Can you strongly state in the intro that “They [invertebrates] directly affect the dynamics of algae number and affect the redistribution of algae’s assemblages”? You do not provide a reference.

Response 6: In the Introduction section, the reference for the statement “They [invertebrates] directly affect the dynamics of algae number and affect the redistribution of algae assemblages [33]” was provided.

 

Point 7: Perhaps the other reviewer requested info about the gut anatomy, but I do not find this info necessary and can be removed.

Response 7: Another reviewer requested detailed information about the gut anatomy from us and that is why it was given.

 

Point 8: The transition into discussion of megacities park from this gut anatomy/feeding preference paragraph is very strange and lacks flow.

Response 8: Some sentences were added to make the discussion flow: ”Both diplopods and soil algae can be found in forest plantations as well as in natural forest ecosystems. Natural forests are not typical for the steppe zone of Ukraine, they are located near the rivers [38]. Park areas of megacities, in most cases, are located in the center of cities. There are tree planted species and lawn cover in the park, where regular park maintenance is taken [39]. Forest stand composition (leaf litter of which serves as a habitat and food for diplopods and soil algae) are different from natural forests”.

 

Point 9: I still do not feel that including discussion of the first park where no millipedes were collected is necessary in the context of the results presented.

Response 9: Information about the second park was excluded from the article.

 

Point 10: There is a point when Heterokontophyta and Streptophyta are treated as one taxonomic lineage, which is not correct. Please revise.

Response 10: Results section was revised and the point, when Heterokontophyta and Streptophyta are treated as one taxonomic lineage, was corrected: “In the case of ash maple (A. negundo) litter Heterokontophyta, Streptophyta divisions are represented by one species each, and its percentage is 14.3% (for every species), while Chlorophyta division is represented by five species (71.4%).”

 

Point 11: Please briefly describe what you mean by disturbance in the first sentence of the discussion.

Response 11: In the first sentence of the Discussion section we briefly described what we meant by leaf litter disturbance: “Regular park maintenance which includes dead wood and leaf litter removal leads to disturbance of the leaf litter as a habitat for litter invertebrates.”

 

Point 12: Please provide algal genus names the first time you present them in any section of the paper.

Response 12: Full algae species names were used for when first time mentioned in each section.

 

Point 13: I still find that there is no definition or description of biomorphs. What are these biomorphs? Where do these categories originate from (i.e., your own categorization, or based on literature?

Response 13: With the term “biomorph” we meant algae life-form. We replaced the term “biomorph” and provided the definition of the term “life-form” which was interpreted by algologists Emiliya Shtina and Maximilian Gollerbakh in 1960-th. One can find the given term “life-form” in the monography of these authors: 

Shtina, E.A.; Gollerbah, M.M. Ekologiya pochvennyih vodorosley [Ecology of soil algae]; Nauka: Moscow, 1976, 143 p. (In Russian)

 

In the article, all edits are marked in red for being easy to find.

 

Best regards,

O. Pakhomov, A. Pokhylenko, I. Maltseva, and Y. Kul’bachko.

Author Response File: Author Response.pdf

Round 3

Reviewer 2 Report

Comments for author File: Comments.pdf

Author Response

Response to Reviewer Comments

Dear Colleague,

We thank you for your edits and valuable comments about our article.

All edits in the article are marked in yellow for being easy to find. Unfortunately, the article is not provided with the line numbers, probably, it is the editorial layout.

 

Point 1: Sometimes diplopods are referred to as saprophytic, sometimes they’re referred to as algivorous. Algivorous is not appropriate, as these organisms are accidentally ingesting the algae as they consume leaf litter, they are not exclusively eating algae.

Response 1: This point was revised through the article and, following your comment, the sentence was rewritten: “Through the diet, diplopods as well as oribatids, collembola, earthworms are possible to swallow passively soil algae along with leaf litter. [31–32].”

 

Point 2:

• Spell out Rossiulus the first time it is mentioned (third sentence)
• Do not italicize “sp.” or “spp.”Insert “a” after “a park area of large”
• Insert “and” after “surface washes, gut washes,”
• Insert “a” before “common but not abundant species in Central and Southern Ukraine”
• Add “For example,” before the sentence about red deer
• Add “of soil algae” after participate in epizoochory and endozoochory”
• Delete “and form an independent assemblages”
• Delete “an” before “active leaf litter decomposers”
• Delete “ones” after “were present in excretions”
• Replace “algivore” with “algivorous”
• Replace “seeds and plants cysts” with diaspores
• Replace thallome with thallus
• Replace unstable, not sure if you mean “resistant” or “susceptible” from how it is written
• Phyla, not divisions
• Replace “saprophagous” with “saprophages”
• Heterokontophyta misspelled several times in discussion (spelled as Hetercontophyta)
• Cannot find definition for cyenallae

Response 2: All recommended edits were taken into account.

* “cyenallae” is misspelled for “cyanellae” and replaced by “blue-green algae”

* “unstable” was replaced for “susceptible”

Point 3: I think a statement about the range of the zoochory for this organism should be added as the last statement of the abstract: “, although it is unknown at what scale these diplopods contribute to the diversity and dispersal of algae”.

Response 3: Recommended part was added to the last sentence of Abstract section: “It was shown that animals can be involved in dispersal of not only plant parts but also entire organisms, although it is unknown at what scale diplopods contribute to the diversity and dispersal of algae.”

 

Point 4: Choose one, diaspores or seeds. Diaspore includes seeds, so when you use it separately, it is confusing.

Response 4: The term “diaspores” was chosen for use trough the article.

 

Point 5: I find the sentences discussing methods of dispersal and then the definitions of zoochory redundant. The terms should be added in parentheses after the previously provided definitions, not in secondary statements.

Response 5: The following sentence was deleted: “We usually distinguish the following methods of dispersal: endozoochory – the dispersal of vital diaspores passed through digestive system (mostly species of birds); synzoochory – the dispersal of diaspores with food supplies or its partial digestion (rodents, ants, and some species of birds); epyzoochory – the dispersal of diaspores results from the passive contact between the diaspores and the animals (fur mammals).”

Also, the terms were added in parentheses after the previously provided definitions: "As it is known, animals can disperse plant diaspores in several ways: 1 – eating diaspores (endozoochory); 2 – storage of diaspores (synzoochory); 3 – attachment of diaspores to the animal body (epizoochory) [1–4]."

 

Point 6: The red deer sentence needs significant editing, it is not understandable in its current form, particularly the phrase starting with “while small animals living in small areas”.

Response 6: The mentioned sentence was rewritten: “For example, red deer takes out of the plant assemblage up to 90% of the diaspores and contribute to the maintenance of plant populations.”

Point 7: Remove redundant sentence: “This contributes to the maintenance of the species diversity of plant communities.”

Response 7: The mentioned sentence was deleted.

 

Point 8: Suggested edit “Methods of diaspore dispersal are most fully studied in vertebrates, as their participation can be assessed visually. Inversely, it is difficult to assess invertebrate dispersal methods due to their small size, an example being saprophytic insects, which live in and among leaf litter and soil.” Delete the sentence that followed the initial sentence in this edit.

Response 8: Suggested edit was taken into account: “Methods of diaspore dispersal are most fully studied in vertebrates, as their participation can be assessed visually. Inversely, it is difficult to assess invertebrate dispersal methods due to their small size, an example being saprophytic invertebrates, which live in and among leaf litter and soil.” Also, the following sentence was deleted.

 

Point 9: Determine, not determining [the possibility of algae development]; Not sure what “the possibly of algae development” means, I think perhaps you mean “affects the diversity of algae present.”

Response 9: All recommended edits were taken into account: “The leaf litter composition and its presence affect the diversity of algae present.”

 

Point 10: Reword statement: leaf litter of which serves as a habitat and food for diplopods and soil algae” this makes it sound like algae eat leaf litter.

Response 10: The mentioned statement was reworded: “Forest stand composition (leaf litter of which serves as a food for diplopods and as habitat both for diplopods and soil algae) are different from natural forests.”

 

Point 11: I do not believe that tree plantations are microhabitats. Either change to “habitats” or add a statement about the understory habitats of a fine scale.

Response 11: In mentioned statement “microhabitat” was used incorrectly, it was changed to “habitat”.

 

Point 12: Need references for the last few statements before Figure 1.

Response 12: Needed references were added for the last few statements before Figure 1: “During the period of study, the temperature (°C) ranged from + 3 °C to + 29 °C (Figure 1). An increase in values of these factors determines the increased vital activity of litter invertebrates and soil algae [16, 33].”

 

Point 13: All methods should be in past tense.

Response 13: Method section was revised.

Point 14: Cannot find definitions for “urbanozem” or “urbic”. Please define or choose alternative, more recognizable terms.

Response 14: Clarification of the mentioned terms was given in the text: “The soil of the park partially retains its natural structure and belongs to the category of surface-transformed soils, so called “urbanozem type”, i.e. urbic layer (anthropogenically transformed) is less than 50 cm [41].”

The reference was replaced by another one in English:

41. Stroganova M., Prokofieva T. Urban soils classification for Russian cities of the taiga zone. European Soil Bureau 2001, 153–156.

 

Point 15: After tree species and common names are introduced, it would be helpful, in my opinion, to exclusively use common names, given that there are numerous species of plants that were introduced. Similarly, authority names are not necessary after the first time they are used. It would be helpful if this change was made for tables as well, e.g. Table 1.

Response 15: Authority names that were used after being mentioned the first time, were removed. Also Latin – is the international language for taxonomic nomenclature that is why, in our opinion, both algae and tree species names should be in Latin, especially in tables. Also, common names of plant/animal one can always be found using Latin name of species.

 

Point 16: Replace “set” with transect, as that is what was used in the abstract.

Response 16: By “set” we meant the exact place, where the research material was taken. Based on this, we replaced “set” with “quadrate”: “Each plot had five transects, the distance between transects was 3 m. Each transect had five quadrates and the distance between quadrates was 3 m. The size of each quadrate was 1 x 1 m squares.”

 

Point 17: The discussion of the number of algal species found in the leaf litter is not pertinent to the questions posed by the study. I believe I have stated this in all three of my reviews: Keep your narrative throughout the manuscript in the context of your research questions. Your research questions, in my estimation, are exclusively what are the species of algae that interact with the diplopod, and what is the difference in the composition of this algal diversity that is present epi- and endobiotically, as well as in the feces of the animal? Differences in algal assemblage among trees does not fit into these questions, at all. A number of tree species leaf litters were assessed to be sure to fully collect the algal diversity present in the park, not to compare their algal assemblages.

Response 17: The discussion of the number of algal species found in the leaf litter discloses our research questions giving an idea about algoflora of the park area, and, in our opinion, in this way, our research may be more readable for a wide audience (botanists, zoologists, ecologists).

 

Point 18: I find the statement added to discuss vertebrates and their inability to contribute to distribution of soil algae problematic. You do not provide any references for this, and this bold of a statement is not necessary or applicable to the main objectives of the paper. Many vertebrates each leaves freshly fallen, and perhaps by accident, likely also ingest soil that can coat fruits, seeds, or leaves. I suggest removing these added statements entirely.

Response 18: The following statement was deleted: “It should be noted that vertebrates, which participate in zoochory, contribute to the dispersal of fruits, berries, and seeds of higher plants. They do not feed on litter where representatives of soil microflora live.”

 

Point 19: The use of "life forms” is still not clear, and I unfortunately do not know Russian. Please see comment below on how to clearly describe and discuss the life forms.

Response 19: Discussion about algal life-forms was added in Discussion section: “The term “life-form” includes unicellular and colonial algae representatives with similar adaptations to environmental conditions. Algae life-forms characterize eco-logical peculiarities of algae regardless of systematic affiliation. The nine life-forms of soil algae were selected conventionally [33]:

Ch-life-form – includes unicellular and colonial green, partially yellow-green algae that exist in the soil layers but grow on the soil surface with a favorable level of moisture;

Cf-life-form – includes microscopic thallus of nitrogen-fixing blue-green algae, capable of producing mucous growths on the surface of the soil;

В-life-form – includes diatoms mobile cells, that inhabit the surface of moist soil or the mucus of other algae. Representatives of this life-form are cold-resistant, light-loving, and many of them are salt-tolerant, but not resistant to drying out;

Н-life-form – includes filiform green and yellow-green algae, susceptible to drought and excessive light. Mottles created by H-representatives often cover stem base of plants and become a basis for complicated communities of soil bloom.

The life-form scale allows establishing the biological spectrum, which reflects ecological conditions of soil and plant communities of the research area.”

 

Point 20: Discussion of why some species are found only in the leaf litter, but not epi- or endozooically is needed. This discussion could include specific reference to the presence or absence of mucilage in the species discussed, which may make them “stickier” and therefore could be susceptible to epizoochory.

Response 21: Discussion section was added by the following: “Apart from size, algae species are capable to produce mucilage that promotes algae cells to stick on diplopods’ body surface.”

Also, the is in Discussion section: “Some of the algae cells are digested, and some after passing through the digestive system remain undamaged (Ch. vulgaris, M. homosphaera, D. olivaceus, V. magna), and then settle into new territories.”

 

Point 21: More specific discussion of the limited dispersal capability of these diplopods is needed, see comment on abstract below. This should be mirrored in the discussion at greater length, and also mentioned in the conclusion section

Response 21: The last paragraph of the Discussion section was rewritten.

 

Point 22: Last statement of Conclusion would be more impactful if you replaced the Ch description of the life form with a brief description of their characteristics, e.g., “Due to ecological features, representatives of the Ch life-forms – those that are resistant to environmental stressors - are most actively distributed by diplopods.

Response 22: The last sentence of the Conclusion section was added by recommended part: “Due to ecological features, representatives of Ch life-forms – those that are resistant to environmental stressors – are most actively distributed by diplopods.”

 

Best regards, O. Pakhomov, A. Pokhylenko, I. Maltseva, and Y. Kul’bachko.

Author Response File: Author Response.pdf