The Dynamics of Soil Mesofauna Communities in a Tropical Urban Coastal Wetland: Responses to Spatiotemporal Fluctuations in Phreatic Level and Salinity
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThe manuscript investigated the effects of the variations in phreatic levels and salinity on Acarina and Collembola. The content of the MS is very interesting, however some improvements should be done; indeed, some parts of the work are not clear (e.g. what the authors mean with morphotype) and the discussion reported too much results (is not a results and discussion section). The statistical analysis is a little poor, and some parts should be reviewed, however I think that with some corrections the overall conclusion are worst of interest.
Introduction
L.43: specify the level of those taxa. Since taxonomic level for Acarina could be hard to define, could be useful for the reader to have this information together with the reference (e.g. Suborder Prostigmata, Order Mesostigmata, Suborder Oribatida; Krantz and Walter, 2009)
L.55: Plantago lanceolata in italic
L.81: Add a few lines introducing how future climate change scenarios are linked to the aim of this MS
Figure 1: the meaning of the different axis titles in relation with the content of the figure are not clear
L.109: “we hypothesize”
L.111: really the interactions of soil mesofauna are not investigated in this MS
Materials and methods
L.115: “took” OR “take”
Figure 4: describe blue and red lines
L. 148: why naming them 3,5,6,10? It is a little confounding since it seems that you had at least 10 plots and not 4
L192:194: I can imagine what are the values for dry and flood period, but I think it would be better to specify them too
L.208-209: very little samples (only 5cm depth) for dividing them in even smaller ones separating the litter…moreover in the results I cannot find those distinction between mesofauna in loose litter and old litter
L.214: At least explain why and where you used Order/Family level, the reasons behind that choice. E.g Family for Collembola and Order for Acarina. Moreover, explain what do you mean for morphotype. Are they the groups named in the introduction or are groups based on morphological traits? In the last case, you should specify those traits..
L.222: A little too simple data analysis for what concern community structure, however this part is clear, but you have to specify what do you mean with morphotype richness (see comment above)
L.248: Are you sure that you can apply Tukey as a post-hoc test for non-parametric analysis like Kruskal-Wallis? Because they have different assumptions and handle and analyse the data in very different ways (e.g. Kruskal-Wallis is based on medians and Tukey on means). The Dunn test is the most common test for post-hoc Kruskal-Wallis, but also Conover or Nemenyi, however not Tukey
Results
All Tables and Figures: If you use Wilcox/Kruskal-Wallis, you did not compare means, but medians. I suggest you to show means values because they are more clear to understand, but delete “means with” from the captions because it is incorrect
L.307: how many Orders and Families? It would be clearer than taxa number
L.322: You should indicate in data analysis that you applied Jaccard index. Moreover, Jaccard is a presence/absence index, why did you not use Bray-Curtis? So you could consider also the impact of the abundances on the habitats similarities/dissimilarities
L.329-331: So, you extracted fauna separating the layers, but really you did not analyse (or show) those differences…
L.474-475: Discussion?
Discussion
Plots should be placed in the results section, but never in the discussion.
L.595: Give some examples of mesofauna taxa
L.597-598: Richness and abundance don’t reflect composition fluctuations and neither dominance or biodiversity patterns
L.599: Collembolans in English or Collembola in Latin
L.613:615: See comment the L.595...this kind of consideration is very interesting!
L.626:638: Those are results, they shouldn’t be reported here. At least, not as a list
Comments on the Quality of English LanguageThe english language is good for me, only minor revisions should be done and are indicated in the suggestions for the authors
Author Response
Review Report (Reviewer 1)
Thank you for your insightful comments and suggestions. We believe these revisions have significantly improved the manuscript.
In response to your feedback and that of the other editors, we have conducted extensive revisions and paraphrasing, resulting in changes to the line and figure numbers throughout the manuscript. The abstract, introduction, and results sections have been thoroughly verified and modified. To assist in your review of these revisions, we have highlighted the sections incorporating your suggestions in blue. This color-coding is designed to efficiently guide you through the modifications, eliminating the need to refer to the original line numbers, which may no longer be accurate due to these adjustments.
Introduction
Reviewer's Comments: L.43: specify the level of those taxa. Since taxonomic level for Acarina could be hard to define, could be useful for the reader to have this information together with the reference (e.g. Suborder Prostigmata, Order Mesostigmata, Suborder Oribatida; Krantz and Walter, 2009)
Response: The suggested edits have been incorporated into the manuscript. The taxonomic levels of the taxa mentioned, such as Suborder Prostigmata, Order Mesostigmata, and Suborder Oribatida, are now specified alongside the references to Krantz and Walter (2009) and Behan & Lindo (2023) to provide further clarification. Additionally, the Class Collembola and orders Arthropleona and Symphypleona have been included with their corresponding references.
Reviewer's Comments: L.55: Plantago lanceolata in italic
Response: The genus and species name Plantago lanceolata has been italicized as suggested, in accordance with the proper convention for scientific nomenclature.
Reviewer's Comments: L.81: Add a few lines introducing how future climate change scenarios are linked to the aim of this MS
Response: As recommended, a few lines have been added to the manuscript, clarifying how future climate change scenarios relate to the objectives of our study. This helps in establishing a stronger context for our research aims.
Reviewer's Comments: Figure 1: the meaning of the different axis titles in relation with the content of the figure are not clear
Response: Figure 1 has been relocated to the discussion section, as recommended by Reviewer 3. Moreover, the description of the figure now includes detailed explanations of all its components, ensuring that the content and purpose of the figure are clearly communicated and understood.
Reviewer's Comments: L.109: “we hypothesize”
Response: The suggested edit has been made to the manuscript.
Reviewer's Comments: L.111: really the interactions of soil mesofauna are not investigated in this MS
Response: We have revised the aim and hypothesis of the manuscript to ensure they accurately reflect the scope of our study.
Materials and methods
Reviewer's Comments: L.115: “took” OR “take”
Response: The term 'take' has been removed as per the suggestion.
Reviewer's Comments: Figure 3: describe blue and red lines
Response: The description of Figure 3 has been updated to include detailed explanations of both the blue and red lines, ensuring a clear understanding of the data presented.
Reviewer's Comments: L. 148: why naming them 3,5,6,10? It is a little confounding since it seems that you had at least 10 plots and not 4
Response: The naming of the plots as 3, 5, 6, and 10 refers to their corresponding pre-established monitoring wells, which have been in place since 2017. This approach was chosen to maintain consistency with the long-term monitoring data available from these wells. We have clarified this rationale in the manuscript and added Figure 4 to aid in visualization.
Reviewer's Comments: L192:194: I can imagine what are the values for dry and flood period, but I think it would be better to specify them too.
Response: To provide clarity, Figure 5 has been revised to include specific phreatic level values for both dry and flood periods.
Reviewer's Comments: L.208-209: very little samples (only 5cm depth) for dividing them in even smaller ones separating the litter…moreover in the results I cannot find those distinction between mesofauna in loose litter and old litter
Response: We appreciate the concern regarding the depth of the samples. The choice of a 5cm depth is based on our preliminary study findings, which indicated that the majority of the mesofauna reside within this layer in our wetland study area. Below this depth, we found anoxic conditions prevalent. In the context of our study, flooding conditions present a unique challenge for soil sampling, primarily due to the loosened state of the saturated soil. We use a PVC ring, 7.62 cm diameter and 5 cm depth, to avoid this issue. Its rigid structure and size facilitate the collection of intact soil cores, even when the soil is waterlogged and loose. This non-compacting method allows us to accurately maintain sample volume and integrity without the compaction that traditional soil corers may cause, ensuring that we recover a representative sample of the soil and its mesofauna content without disturbance. Additionally, it guarantees uniform sample volumes across various hydroperiods encountered in our study, which is essential for comparing soil mesofauna populations and ensuring the reproducibility of the study.
The distinction between mesofauna in loose litter and old litter has now been thoroughly analyzed and discussed in Sections 3.2, 3.3.2, and 3.3.3.
Reviewer's Comments: L.214: At least explain why and where you used Order/Family level, the reasons behind that choice. E.g Family for Collembola and Order for Acarina. Moreover, explain what do you mean for morphotype. Are they the groups named in the introduction or are groups based on morphological traits? In the last case, you should specify those traits.
Response: We identified the collected microarthropods to the most specific taxonomic level feasible, which ranged from class to family. This varied based on the discernible characteristics that could be reliably observed and the taxonomic expertise available. Our analysis focused on the data collected for the primary taxa of mites (suborder Oribatida, order Mesostigmata, and suborder Prostigmata) and two suborders of springtails (Arthropleona and Symphypleona), which are predominant in mesofauna communities and serve as bioindicators of ecosystem changes. The assessment extended to examining the distribution patterns and the occurrence of mesofauna families along the gradients of phreatic levels and salinity to gain insights into the adaptive mechanisms and preferred habitats of these soil-dwelling microarthropods.
In ecological research, morphotypes are sometimes utilized as surrogates for species composition when species-level identification is constrained by taxonomic limitations, a lack of expertise, or the presence of numerous cryptic species. This is particularly common in biodiversity studies with a vast number of species, where exhaustive taxonomic identification may be impractical.
Initially, our manuscript used "morphotypes" to describe groups based on observable morphological traits, such as color (dark, light, or patterned) and shape (elongated, rounded, etc.), including distinguishing features like setae type and body segmentation. Upon further consideration, we have opted to omit the term "morphotype" to ensure clarity and standardization in our approach.
Reviewer's Comments: L.222: A little too simple data analysis for what concern community structure, however this part is clear, but you have to specify what do you mean with morphotype richness (see comment above)
Response: We appreciate the constructive feedback on the data analysis section. Our intent was to balance methodological rigor with clarity and interpretability, providing an analysis that is both accessible and appropriate for the scope of our study. We understand that the analytical methods may seem straightforward; however, they were carefully chosen to clearly demonstrate our study's aim: to evaluate the impacts of spatiotemporal variations in phreatic levels and salinity on soil mesofauna assemblages in a tropical urban coastal wetland.
Our hypothesis posits that these spatiotemporal fluctuations play a significant role in shaping the diversity and abundance of soil mesofauna communities. The selected statistical approaches, including non-parametric tests and general regression modeling, were deployed to robustly test this hypothesis, given the data and its ecological context.
We believe the data analysis, as described, effectively addresses the central questions of our research. However, we remain open to further suggestions and are willing to consider additional analyses that the reviewers may deem necessary to enhance the depth of our study.
Reviewer's Comments: L.248: Are you sure that you can apply Tukey as a post-hoc test for non-parametric analysis like Kruskal-Wallis? Because they have different assumptions and handle and analyse the data in very different ways (e.g. Kruskal-Wallis is based on medians and Tukey on means). The Dunn test is the most common test for post-hoc Kruskal-Wallis, but also Conover or Nemenyi, however not Tukey.
Response: You are correct; the Tukey post-hoc test is not appropriate for non-parametric analysis such as the Kruskal-Wallis test. We have amended this in the manuscript by replacing the Tukey test with the Dunn test, which is indeed more suitable for post-hoc analysis after a Kruskal-Wallis test. We have also reviewed and updated our statistical analysis methods to ensure they are appropriate and correctly applied.
Results
Reviewer's Comments: All Tables and Figures: If you use Wilcox/Kruskal-Wallis, you did not compare means, but medians. I suggest you to show means values because they are more clear to understand, but delete “means with” from the captions because it is incorrect
Respond: The captions in all tables and figures have been revised as follows: "Values not connected by the same letter indicate significant differences (p < 0.05)."
Reviewer's Comments L.307: how many Orders and Families? It would be clearer than taxa number
Response: The text has been modified to include the total number of families for each suborder (Oribatida, Prostigmata, Symphypleona and Arthropleona), and order (Mesostigmata and Collembola). Additionally, Figure 9 has been updated with this information.
Reviewer's Comments L.322: You should indicate in data analysis that you applied Jaccard index. Moreover, Jaccard is a presence/absence index, why did you not use Bray-Curtis? So you could consider also the impact of the abundances on the habitats similarities/dissimilarities
Response: The Jaccard index analysis has been replaced by Bray-Curtis and Non-metric Multidimensional Scaling (NMDS).
Reviewer's Comments L.322 L.329-331: So, you extracted fauna separating the layers, but really you did not analyze (or show) those differences…
Response: The distinction between mesofauna in loose litter and old litter has now been thoroughly analyzed and discussed in Sections 3.2, 3.3.2, and 3.3.3, as well as in the discussion section.
Reviewer's Comments L.474-475: Discussion?
Response: The sentence has been moved to the discussion section.
Discussion
Reviewer's Comment: Plots should be placed in the results section, not in the discussion.
Response: In accordance with the suggestions provided, the figure that discussed specific habitats/plots has been removed from the discussion section. This change ensures that our discussion now focuses more directly on the broader findings and implications of our study, aligning with standard academic practices for manuscript structure.
Reviewer's Comment: L.595: Provide some examples of mesofauna taxa.
Response: Additional examples have been included in this section as suggested.
Reviewer's Comment: L.597-598: Richness and abundance do not reflect composition fluctuations, nor do they indicate patterns of dominance or biodiversity.
Response: The discussed section has been revised to address this issue more accurately.
Reviewer's Comment: L.599: Use 'Collembolans' in English or 'Collembola' in Latin.
Response: The term 'Collembola' has been used consistently in the revised manuscript.
Reviewer's Comment: L.613-615: See comment on L.595...this kind of consideration is very interesting!
Response: Additional examples have been included in this section as suggested.
Reviewer's Comment:L.626-638: These are results, not discussion points. They should not be reported here, at least not as a list.
Response:The mentioned section has been removed from the discussion to ensure it aligns more appropriately with the structure of the manuscript.
Reviewer 2 Report
Comments and Suggestions for AuthorsIntroduction
L-31 – Edit ‘arthropods assemblages’ as ‘arthropod assemblages’
L-32 - The reference is given in text format. Substantiate the sentence with more reference as it is a general statement.
L-35 – Edit ‘hot spots zones’ as ‘hot spot zones’
L-41 – Instead of writing references as [4,5,6,7], the authors can use [4-7]
L-46 – Follow a uniform method for adding reference numbers in the text. Please avoid the spaces between each reference number and follow the same throughout the text.
L-55 - Write the species name in italics
Revise the figure 1. You can add images to make it more attractive.
L-109 – Rewrite hypothesis as ‘hypothesise’
Introduction required massive refinement regarding grammatical and typological errors
Materials and Methods
L-115 – Delete ‘take’
The images in Fig 2 is represented as A, B and C; whereas fig 3 is given ‘a’ and b. Please follow uniform way for representing aub-figures
L-126 – Remove space before ‘The study’ and ‘In 2020’
The axes for fig 3a are not specified
L-143 – Add full stop after [33]
Paraphrase the sentence in lines 150 – 152
L-152 - Remove space before ‘each’
Figure 5 is confusing and not conveyable
Result
L-285 – Add space before ‘MWR’
What does A. B, C and D indicate in figures 7, 8, 9, 11, 13, 15, 16, 18 and 19
Figure 7 – One of the given legend is in italics, please correct it.
Please arrange legends according to the order given in the figure
L-202 - the 5 in the bracket is not needed.
What do you mean by the substrate sample in L. 207? And what is the other component in the dilution besides water?
What is 'NOAA 9755371' in L. 219?
What is the importance of giving date including the day? Has it any statistical importance?
Tables can be formatted to make it more attractive
Result section required refinement regarding the figures, tables, grammatical and typological errors.
Reference
Remove all the uncited references from the back and add numbers to each reference cited in the text.
Comments on the Quality of English LanguageMinor revision required
Author Response
Review Report (Reviewer 2)
Thank you for your insightful comments and suggestions. We believe these revisions have significantly improved the manuscript.
In response to your feedback and that of the other editors, we have conducted extensive revisions and paraphrasing, resulting in changes to the line and figure numbers throughout the manuscript. The abstract, introduction, and results sections have been thoroughly verified and modified. To assist in your review of these revisions, we have highlighted the sections incorporating your suggestions in yellow. This color-coding is designed to efficiently guide you through the modifications, eliminating the need to refer to the original line numbers, which may no longer be accurate due to these adjustments.
Introduction
Reviewer's Comments: L-31 – Edit ‘arthropods assemblages’ as ‘arthropod assemblages’
Response: The suggested edit to 'arthropod assemblages' has been made to the manuscript.
Reviewer's Comments: L-32 - The reference is given in text format. Substantiate the sentence with more references as it is a general statement.
Response: The in-text reference format has been corrected, and the sentence has been further substantiated with two additional references that provide broader context and support:
Reviewer's Comments: L-35 – Edit ‘hot spots zones’ as ‘hot spot zones’
Response: The suggested edit to 'hot spot zones' has been made to the manuscript.
Reviewer's Comments: L-41 – Instead of writing references as [4,5,6,7], the authors can use [4-7]
Response: The suggested edit to use [4-7] for consecutive references has been made to the manuscript.
Reviewer's Comments: L-46 – Follow a uniform method for adding reference numbers in the text. Please avoid the spaces between each reference number and follow the same throughout the text.
Response: The manuscript has been revised to ensure a uniform method for adding reference numbers, with no spaces between them.
Reviewer's Comments: L-55 - Write the species name in italics. Revise figure 1. You can add images to make it more attractive.
Response: Species names have been italicized, and Figure 1 has been revised with the addition of images to enhance its appeal, it has been relocated to the discussion section, as recommended by Reviewer 3.
Reviewer's Comments: L-109 – Rewrite 'hypothesis' as ‘hypothesise’. The introduction required massive refinement regarding grammatical and typological errors.
Response: As per the suggestion, the term 'hypothesis' has been changed to 'hypothesize' to reflect the verb form in American English spelling, ensuring consistency with the style of English used throughout the manuscript. Additionally, the introduction has been thoroughly reviewed and revised to correct all grammatical and typological errors.
Materials and Methods
Reviewer's Comments: L-115 – Delete ‘take’, the images in Fig 2 is represented as A, B and C; whereas fig 3 is given ‘a’ and b. Please follow uniform way for representing a and b-figures
Response: The term ‘take’ has been removed, and figure labeling has been standardized to consistently use uppercase 'A' and 'B'.
Reviewer's Comments: L-126 – Remove space before ‘The study’ and ‘In 2020’ The axes for fig 3a are not specified
Response: The extra spaces have been removed. Axes labels for Figure 3A have been specified and described.
Reviewer's Comments: L-143 – Add full stop after [33] Paraphrase the sentence in lines 150 – 152
Response: A full stop has been added after [33], and the text in lines 150 – 152 has been paraphrased for clarity.
Reviewer's Comments: L-152 - Remove space before ‘each’ Figure 5 is confusing and not conveyable
Response: The space before 'each' has been removed. Figure 5 has been revised for clarity and the description expanded for better understanding.
Reviewer's Comments L-202 - the 5 in the bracket is not needed.
Response: It was deleted.
Reviewer's Comments: What do you mean by the substrate sample in L. 207?
Response: The term "substrate" refers to the underlying layer in which organisms reside, including a variety of materials such as soil, wood, leaf litter, or any other organic or inorganic matter. For the purposes of clarity and specificity, we have revised the manuscript to replace "substrate" with "soil samples, including litter layers," to accurately reflect the focus of our research.
Reviewer's Comments: And what is the other component in the dilution besides water?
Response: There seems to have been a misunderstanding. The sentence in question was intended to describe the rationale behind the timing of our sampling protocol. To reduce variability in environmental factors such as tidal influence, temperature, and soil water content among different habitats, sampling was conducted strictly between 7:00 am and 10:00 am. This timing ensured that conditions were as consistent as possible across the various habitats studied. The manuscript has been edited for clarity to avoid further confusion regarding this matter: “Sampling was carried out from 7:00 am to 10:00 am to ensure consistent conditions across habitats in terms of tidal influence (see Table 2), temperature, and soil water content.”
Reviewer's Comments: What is 'NOAA 9755371' in L. 219?
Response: 'NOAA 9755371' is the identification number for the NOAA La Puntilla Station, located in San Juan, Puerto Rico. This station's data was utilized in our study for climatic and tidal information. The manuscript text has been updated to read: "Data was obtained from NOAA La Puntilla Station (ID number 9755371), San Juan, Puerto Rico."
Reviewer's Comments: What is the importance of giving date including the day? Has it any statistical importance?
Response: Including the specific date, down to the day, is critical for the verification of data against NOAA's Station Records, which can have daily variations that are significant to our study's analysis. This level of detail ensures the reproducibility and accuracy of our research findings.
Reviewer's Comment: Tables can be formatted to make them more attractive.
Response: We appreciate this suggestion and have revised the table formats to enhance their visual appeal and readability, aligning with the journal's standards for publication.
Result
Reviewer's Comments:
- L-285 – Add space before 'MWR'.
- What do A, B, C, and D indicate in Figures 7, 8, 9, 11, 13, 15, 16, 18, and 19?
- Figure 7 – One of the legends is in italics; please correct it. Please arrange the legends according to the order given in the figure.
Response:
- A space was added before 'MWR' on line 285.
- The letters A, B, C, and D in Figures 7, 8, 9, 11, 13, 15, 16, 18, and 19 represent groupings wherein values not connected by the same letter indicate statistically significant differences (p < 0.05). This explanation has been added to the descriptions of each figure for clarity.
- The italicized legend in Figure 7 has been corrected, and the legends have been rearranged to match the order presented in the figure.
Reviewer's Comments: Result section required refinement regarding the figures, tables, grammatical and typological errors.
Response: We have undertaken a comprehensive review of the figures and tables to enhance their clarity and presentation. Each figure and table have been carefully revised to ensure that it effectively communicates the data and aligns with the manuscript's narrative.
We have meticulously proofread the entire section to correct all grammatical and typographical errors. Furthermore, we have reviewed our analytical approach to eliminate any duplicity in the data presented. Where necessary, additional analyses have been conducted to ensure that our results comprehensively address the aim of the study.
Reference
Reviewer's Comments: Remove all the uncited references from the back and add numbers to each reference cited in the text.
Response: We have carefully reviewed the reference list and removed all entries that were not directly cited within the text. Additionally, each reference cited in the text has been assigned a unique number, ensuring that the reference list is now fully congruent with the in-text citations. This numbering also follows a sequential order for ease of cross-referencing between the text and the reference list.
Reviewer 3 Report
Comments and Suggestions for AuthorsReview report of the paper arthropoda-2652033
Article arthropoda-2652033 has been reviewed. This is a generally interesting article. It presents many relevant results emanating from a fairly solid methodology. Some minor corrections are proposed in this report before its publication.
The abstract should begin with context. A brief presentation of the methodology used must also be made in this part. Some figures relating to the results should also be included in the abstract. It is not good for an abstract to have no figures as is the case.
The introduction to an article must not contain a figure. To support your statements in the introduction, rely only on other authors who have worked on the issue before you.
More recent references should be added to the introduction. This part contains less than 5 articles published after 2020.
Author Response
Review Report (Reviewer 3)
Thank you for your insightful comments and suggestions. We believe these revisions have significantly improved the manuscript.
In response to your feedback and that of the other editors, we have conducted extensive revisions and paraphrasing, resulting in changes to the line and figure numbers throughout the manuscript. The abstract, introduction, and results sections have been thoroughly verified and modified. To assist in your review of these revisions, we have highlighted the sections incorporating your suggestions in gray. This color-coding is designed to efficiently guide you through the modifications, eliminating the need to refer to the original line numbers, which may no longer be accurate due to these adjustments.
Reviewer's Comments: The abstract should begin with context. A brief presentation of the methodology used must also be made in this part. Some figures relating to the results should also be included in the abstract. It is not good for an abstract to have no figures as is the case.
Response: We have revised the abstract to provide a clearer context and included a succinct overview of the methodology. Furthermore, in line with your suggestion, we have incorporated a graphical abstract that visually summarizes key findings and methodologies, thereby enhancing the abstract's comprehensiveness and appeal.
Reviewer's Comments: The introduction to an article must not contain a figure. To support your statements in the introduction, rely only on other authors who have worked on the issue before you.
Response: Acknowledging your guidance, we have relocated Figure 1 from the introduction to the discussion section. This change ensures that the introduction now solely focuses on contextualizing the research with relevant literature, as per standard academic conventions.
Reviewer's Comments: More recent references should be added to the introduction. This part contains less than 5 articles published after 2020.
Response: The introduction has been thoroughly updated to include more recent references. We have carefully selected additional studies published after 2020, ensuring that the introduction reflects the latest research and developments in the field.
Reviewer 4 Report
Comments and Suggestions for AuthorsThe paper has certain scientific significance and can provide theoretical support for monitoring and adaptive ecosystems management to ensure their long-term health and sustainability. The reviewer suggests that the author make minor revisions to the paper. The specific opinions are as follows。
1. Table 2. How to determine the Moderate Dry and Wet Hydroperiod when the sampling time is so close (6/25/2020 and 6/9/2021).
2. Will factors such as water temperature and pH during different Hydroperiod affect the structure and abundance of Soil Mesofauna Communities?
3. How did you verify and determine the validity of the sampling data with fewer sampling times？（Only one hydroperiod was sampled）
4. How to determine that changes in biomass are only related to salinity and hydrological cycles, and how to consider the impact of other environmental factors?
Author Response
Review Report (Reviewer 4)
Thank you for your insightful comments and suggestions. In response to your feedback, we have conducted revisions and paraphrasing. To assist in your review of these revisions, we have highlighted the sections incorporating your suggestions in yellow.
Reviewer's Comment: Table 2. How to determine the Moderate Dry and Wet Hydroperiod when the sampling time is so close (6/25/2020 and 6/9/2021).
Response: The purpose of Table 2 is to illustrate tidal variations affecting the study area at the sampling dates. By coordinating sampling between 7 to 10 am, we ensured consistent conditions across habitats regarding tidal influence, as this timeframe corresponds with the transition from high to low tide. To simplify the data presentation and minimize potential confusion, the column indicating the hydroperiod for each sampling day was removed from Table 2.
Addressing the proximity and classification of sampling periods, it is important to recognize that general hydro-patterns in wetlands, which are typically seasonal in water level variation (early dry, dry, early wet, and wet conditions), exhibit significant variability across and within different wetlands types and climates conditions (Batzer 2006). In coastal wetlands, hydrological conditions arise from a spatio-temporal synergy of factors: a) local weather conditions impacting in situ precipitation, tidal flow, and river discharge (Tiner, 2018); b) freshwater inputs from surface, subsurface, or deep subsurface flows from rivers, channels, and aquifers; c) tidal seawater inflow (Lugo et al., 1988; Manzoni et al., 2020).
Our study considers the complex history of hydrological modifications at Ciénaga Las Cucharillas Natural Reserve. These modifications include site filling, which altered its microtopography, the construction of a flood control channel that directs a flow of fresh water to the wetland from the upper and middle parts of the basin, and restricted seawater exchange resulting from the dike effect of an outflow water pump structure at the channel's mouth, all of which significantly influence the hydro regime. The Reserve is affected by the interplay of marine-terrestrial subsurface connectivity, local weather conditions, and regional climate variability, impacting water source inputs. These factors markedly influence the spatial and temporal patterns of wetting and drying periods, culminating in a unique regime characterized by variations in the frequency, duration, and timing of inundation. At the study site, flooding results from the combined effects of regional/local precipitation and tidal fluctuations. The duration of these flood events varies, ranging from several months to merely a few days or even just hours within a single day, depending on the interplay of climate dynamics.
The hydroperiod classification utilized in this study was predominantly predicated on the phreatic level values recorded at the time of sampling. This approach was adopted due to the direct influence of these values on the soil environment. Additionally, local rainy-day conditions and the mean tidal daily range in the 14 days preceding the sampling date were also considered. These factors are pertinent as they significantly affect the dry and wet cycles of the wetland, as well as the site's phreatic level at the sampling time. The selected sampling days
were chosen to represent a range of conditions in the phreatic level, as depicted in Figure 5. These varying conditions are indicative of differences in soil water content and salinity.
Conditions were categorized as "moderate dry" and "moist" at phreatic levels of -0.56 m and -0.38 m, respectively. Furthermore, "wet" and "flood" conditions were identified at phreatic levels of -0.12 m and at or above the ground level (0 m). It is noteworthy that the Moist sampling period, which took place on March 19, 2021, occurred amidst flooding events. Specifically, the site experienced flooding both a week before and after the sampling date, although the week of the sampling itself was dry. The sampling for this period was conducted immediately following the first flood event. Additionally, the Flood sampling date, which was on October 23, 2020, coincided with the receding of floodwaters. Prior to this date, the wetland had been subjected to significant climatic events, including tropical storms Isaias and Laura, followed by a prolonged rainy period that lasted until the end of October 2020. This resulted in approximately three months of flooding at the site, spanning from August 2020 to October 2020 (NOAA, 2020).
The above clarifications have been incorporated into our manuscript to enhance understanding of our methodologies and findings.
Reviewer's Comment: Will factors such as water temperature and pH during different Hydroperiod affect the structure and abundance of Soil Mesofauna Communities?
Response: Previous research, mostly developed in template zones, has established that the distribution and assemblage of soil arthropods are influenced by factors like temperature and pH (Lavelle et al., 2003, 1997; Anderson et al., 1989; Culliney, 2013). Our preliminary evaluation revealed that both water and soil temperatures remained consistent at 26.00°C, with no significant daily or periodic variations from the surface to a depth of 10 cm. This consistency is characteristic of isohyperthermic soil temperature regimes in the Caribbean Tropic Regions, which are marked by minimal variation throughout the year. Consequently, temperature was not included as a parameter in this study. In addition, samples were collected during the hours of 7 to 10 AM, under vegetation, which provides shade to the understory and soil. This maintained constant temperatures, keeping them low and preventing fluctuations throughout the sampling time.
Significant variations in pH were observed across different hydroperiods, and we found very low (.06, p=.003) but significant correlations between the abundance of mesofauna across hydroperiods. The submitted manuscript focuses on variations related to phreatic level and salinity because these factors showed significant moderate correlations with mesofauna abundance and richness (Table 6). Among all the measured factors, our generalized regression model revealed that they were the most influential predictors in explaining these variations. Habitat type, phreatic level, and salinity collectively accounted for 45% (r-square = 0.45) of the variability in mesofauna richness and 40% (r-square = 0.40) in mesofauna abundance.
Reviewer's Comment: How did you verify and determine the validity of the sampling data with fewer sampling times (Only one hydroperiod was sampled)?
Response: Ciénaga las Cucharillas exhibits a unique hydrological regime, marked by the dynamic interplay of freshwater and seawater inputs, significantly influenced by climatic and weather variability. The impact of climate change on precipitation and tidal patterns in the Caribbean region further amplifies this complexity. Unlike many other study sites, the hydroperiod conditions at Ciénaga las Cucharillas do not adhere to predictable seasonal patterns. The wetland is characterized by complex drying and wetting dynamics, that differ in duration during the year, extending from several months to just a few days or hours. This unpredictable variability makes replicating conditions across multiple hydroperiods extremely challenging.
In our study, we strategically chose to sample different phreatic level conditions to encapsulate a range of scenarios including dry, flood, immediate post-inundation, and wet conditions. This methodology was designed to provide a comprehensive understanding of soil mesofauna responses under diverse environmental stresses. Preliminary evaluations have shown that these varying hydroperiod conditions significantly impact soil properties, with distinct differences observed across different habitats due to variable microtopography. This is clearly demonstrated in our findings.
The significant negative correlations we quantified between phreatic levels and salinity, observed across various habitats and spanning different hydroperiods, are pivotal to our study. Furthermore, the documented responses of mesofauna to these fluctuating conditions provide robust support for the validity of our research approach. These findings not only demonstrate the soundness of our methodology but also underscore the intricate interplay between environmental factors and mesofauna assemblages in this dynamic ecosystem.
This research offers valuable insights into the assemblages of soil mesofauna in a tropical urban coastal wetland. It lays the groundwork for understanding the intricate responses to fluctuating phreatic levels and salinity. The implications of our findings thus not only contribute to the current body of knowledge but also pave the way for future studies in similar environments impacted by climate change.
Reviewer's Comment: How to determine that changes in biomass are only related to salinity and hydrological cycles, and how to consider the impact of other environmental factors?
Response: The generalized regression model performed for this study indicated that habitat type, phreatic level, and salinity together accounted for 45% (r-square = 0.45) of the variability in mesofauna richness and 40% (r-square = 0.40) in mesofauna abundance, as detailed in Table 7. The analysis of effects suggests that habitat type and phreatic level were the most influential predictors in explaining these variations. These two factors exerted the strongest impact on mesofauna richness and abundance within the model. It is inferred that the remaining 60% of the variability in mesofauna richness and abundance could be attributed to other soil
constituents (soil texture, organic matter content), biological processes (like reproduction and mortality) and biotic interactions (such as predation, competition, and facilitation) not measured in this study, either acting independently or in combination.
The above clarifications have been incorporated into our manuscript to enhance understanding of our methodologies and findings.
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