Relative Influence of Salinity in the Flow and Accumulation of Organic Carbon in Open-Water Karstic Mangroves

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

In section 2.1, a location map will help the audience better understand where those sites are. Site photos also will help the audience understand the details of the ecosystem at sites.

Author Response

Comments 1: Thank you for pointing this out. we agree with this comment. Therefore, we have included the map 

In addition to this, the bibliographic references have been adjusted to the correct format, and it has been reviewed to ensure everything is in English

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

Dear Authors,

Congratulations on your manuscript titled "Relative influence of salinity in the flow and accumulation of organic carbon in open-water karstic mangroves." The study presents important data on the effects of salinity, local characteristics, and vegetation on the productivity and organic carbon dynamics of mangrove ecosystems. Your work includes robust data, a well-structured discussion, and strong results.

There are only minor adjustments needed to improve the overall quality and resolve some contradictions in the text. I have provided all recommendations in the attached PDF.

Congratulations on your work, and best regards.

Comments for author File: Comments.pdf

Comments on the Quality of English Language

There is one issue that must be fixed. I have cited it in the attached manuscript PDF.

Author Response

The comments made in the document have been adjusted, and they are summarized as follows:

Comment 1: Maintaining a consistent pattern improves readability and enhances the manuscript's visual appeal.
Response: There is only one figure in color, which relates to the mangrove species. We believe that associating the results with the distinct colors of the species could help the reader better interpret the findings.

Comment 2: The reference forest is too far from the values, leading to a misunderstanding for the reader. Try reducing the sentence length or breaking it into two for clarity.
Response: Your comment is unclear as no reference point has been provided. We are unsure what this comment refers to.

Comment 3: Since the data span several years, I suggest creating a line chart with points and standard errors for each year. The lines should connect the years, since production is continuous over time.
Response: The graph has been adjusted according to these guidelines.

Comment 4: Please remove the inner lines from all tables.
Response: Adjusted in the document.

Comment 5: The results in Table 3 conflict with this sentence. Please revise for consistency.
Response: This comment is unclear. We have reviewed the information, but we do not understand what it is referring to.

Comment 6: If no significant correlation was found, report p should be > 0.05.
Response: Adjusted in the document.

Comment 7: Please use three decimal places. Apply the same in Figure 5.
Response: Adjusted in the document.

Comment 8: DBH was not different between areas! Either your table results are reversed, or there is an inconsistency—please check.
Response: We have reviewed the statistical analyses and identified an error in the DBH differences, which has been corrected in the table to align with the results.

Comment 9: Cite the reference at the end of the sentence to avoid placing it at the beginning of the paragraph.
Response: Adjusted in the document.

Comment 10: Line 651: I understand your point regarding the results in Table 2. The letter 'A' indeed indicates no significant differences in total root production. I have reviewed this section and corrected any inconsistencies to ensure the interpretation aligns with the data presented.
Response: Regarding the statement about partial corroboration: I agree with your suggestion to state that factors other than salinity govern root production. The study demonstrates that, in some mangroves, root production is influenced by a range of factors, and local environmental conditions are equally important as salinity. I have revised the text to reflect this more clearly.

Comment 11: Review conclusion
Response: I have reviewed and revised this paragraph to accurately reflect that factors other than salinity play a significant role in governing root production. This revision ensures that the conclusion is consistent with the rest of the findings. I agree that salinity does not solely govern carbon production. I have softened the wording to reflect that local environmental conditions and species composition are equally significant, without overstating the role of salinity. These adjustments have been made to ensure the conclusions and overall narrative are more accurate and aligned with the findings. Adjusted in the document.

Comment: Review bibliography
Response: The bibliography has been adjusted according to the required format and recommendations provided.

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

The study on " RELATIVE INFLUENCE OF SALINITY IN THE FLOW AND  ACCUMULATION OF ORGANIC CARBON IN OPEN-WATER KARSTIC MANGROVES " is interesting, however, the manuscript can be improved by addressing the following observations:

Change the keyword salinity for another one, since the key words should not be in the title.

Add in the final part of the introduction the objective of the research

Keywords: mangrove, blue carbon, root production, litter production, salinity

Lack of adding a map showing the study area.

For a better experimental design, attach a diagram where see sñale sñale sñale in the experimental design section.

Author Response

Comentario 1 : Cambiar la palabra clave "salinidad" por otra, ya que no deben aparecer en el título.
Respuesta : La palabra "salinidad" en las palabras clave se ha cambiado por "déficit hídrico", tal como se solicitó.

Comentario 2 : Añadir el objetivo de la investigación al final de la introducción.
Respuesta : El objetivo de la investigación se ha añadido al final de la introducción, tal como se solicitó.

Comentario 3 : Falta un mapa que muestre el área de estudio.
Respuesta : Se ha añadido un mapa que muestra el área de estudio, tal como se solicitó.

Comentario 4 : Para un mejor diseño experimental, incluya un diagrama que ilustre el diseño experimental en la sección correspondiente.
Respuesta : Se ha incluido un diagrama del diseño experimental en la sección de diseño experimental, tal como se solicitó.

Author Response File: Author Response.pdf

Reviewer 4 Report

Comments and Suggestions for Authors

There is a need for more data on the C cycle in mangrove communities in different habitats. This study makes a useful contribution as it explores the annual C content in litterfall and ingrowth root cores for communities growing across a wide salinity range. One of the weaknesses of the study is that one site was only sampled over one year and this did not overlap with the sampling period for the other 3 sites. There is reuse of some root data (to estimate C contents) from Reference 13, but I am unable to ascertain whether there is any overlap with Reference 31 as the citation is incomplete.

In general, the manuscript is well presented but can be improved as I have indicated below.

Section 1 – Provide more background to the study prior to stating the objectives. For example, in the earlier paper, the authors found that there was a relationship between total and fine root biomass and PSU. So, this is not a new working hypothesis. How does the current study build on those observations?

Section 2.2 – provide a brief reason why the number of plots differed between sites.

In the earlier paper of these authors, root biomass production was determined using ingrowth soil cores after 12, 18 and 24 months. In the present study it is not stated what time period was used for the ingrowth cores at SBTA. This section would benefit from further information.

Furthermore, the authors must clearly state that they took root biomass data from the earlier study and estimated the C for these published values (BHC, BHF and SCTA). Where primary data from a previous paper have been used to estimate C (e.g., Table 2), this must be stated in the Table heading.

Where different time periods have been used to gather data, mention this in the Table and Figure captions. For example, in Figure 1 presumably the data for 3 sites were combined across a number of years whereas those for SBTA are for just 1 year. See also Table 2. Differences in litterfall and flowering intensity across years are known to occur in other mangrove regions.

Figure 1 a/b can be combined with Figure 2 making 3 vertical panels for ease of comparison in the order: a) Total, b) Species, then c) Components.

Why is there no value for basal area for other species in Table 1?

Figure 1 - use the English terminology that was defined earlier [limnetic systems (< 0.5 PSU), oligohaline (0.5 to 5 PSU), mesohaline (5 to 18 PSU), polyhaline (18 to 30 PSU), euhaline (30 to 40 PSU) and hyperhaline (> 40 PSU)]. There are similar errors elsewhere. Note that litterfall is misspelt on the y axes.

Figure 3 – Use the same terminology as in Line 100, wet season in place of rainy season. Do this in the text as well.

The monthly analysis for SBTA (Table 5) was undertaken as this site was only sampled across 1 year. This analysis sits out on a limb and I recommend it be excluded unless a monthly analysis is performed for the other sites to enable a meaningful comparison of seasonal drivers.

The explanation for Figure 5 is not so clear. Explain in more detail about how the lag effect was identified, its duration and meaning.

Exploration of a “direct relationship between salinity and root production” appears to be missing from the results. Why is this not shown in comparison to litterfall C in Figure 5?

I am not sure that the two appendices add value to the paper. Appendix 2 has largely been published previously. It is sufficient to draw the reader’s attention to the previous works and distil out a few key points in the discussion.

In places, the Discussion is a bit too broad and some reduction of content is warranted.

The Conclusions could focus more on the significance of the findings and areas where further research efforts would be productive.

Minor edits: Add the unit of measure to Line 109, Lines 133-34 give the definition earlier when first mentioned, Line 301 the 6 decimal points for p is excessive, remove Lines 397-399. Check for minor errors such as mean ± EE (Line 235), mean ± SE (Line 252), mean ± ES (Line 256).

Comments on the Quality of English Language

Minor errors detected and some Spanish!

Author Response

• Comment: There is a need for more data on the C cycle in mangrove communities in different habitats. This study makes a useful contribution by exploring the annual C content in leaf litter and root growth cores in communities growing across a wide range of salinity. One of the weaknesses of the study is that one site was sampled for only one year, and this did not align with the sampling period of the other three sites. There is reuse of some root data (to estimate C content) from Reference 13, but I cannot determine if there is any overlap with Reference 31, as the citation is incomplete.
  Response: The secondary information used was based on a doctoral thesis [31] and an article stemming from that thesis [13]. Although the sampling years of the references differ from the primary data used, the inclusion of the SBTA forest in this study allows for addressing the influence of salinity on mangrove forests with contrasting salinity levels and structural development, reinforcing the consistency and validity of the data used to estimate carbon content in the roots. Although the results for SBTA are based on production data found in 2022, this temporal variability does not diminish the inclusion of this site in the study. By adding a forest with distinct ecological and structural characteristics, the study provides a more comprehensive view of how salinity influences the carbon cycle in mangroves. The use of annual averages for different habitats (BHC, BHF, and SCTA) allows for a coherent comparison between them, despite the temporal differences in sampling.

• Comment: Section 1 – Provide more background to the study before stating the objectives. For example, in the previous paper, the authors found a relationship between total and fine root biomass and PSU. So, this is not a new working hypothesis. How does the current study build on those observations?
  Response: In the previous paper, the authors found a significant relationship between total and fine root biomass and PSU, suggesting that salinity could have a direct impact on the development and structure of roots in mangrove communities. The current study builds on these previous observations by delving deeper into understanding how salinity affects not only root biomass but also the carbon cycle in mangrove communities. Instead of exploring a new hypothesis, this study extends already established relationships by analyzing the annual carbon content in leaf litter and internal roots of mangroves in habitats with contrasting salinities.

• Comment: Section 2.2 – Provide a brief reason why the number of plots differs between sites.
  Response: This study is partly based on secondary information from Medina (2016) and Medina et al. (2021), and the SBTA forest was included as an additional site. The number of plots in SBTA differs from those in the other forests due to specific access conditions for that site, which limited the number of plots that could be sampled compared to the other forests.

• Comment: In the authors' previous paper, root biomass production was determined using growth soil cores after 12, 18, and 24 months. In the present study, it is not stated what time period was used for the growth cores in SBTA. This section would benefit from more information.
  Response: This was clarified in the article as follows: To determine root production in SBTA, the same methodology used by [13] in the BHC, BHF, and SCTA forests was implemented. Specifically, root biomass production for this forest was determined using growth soil cores after 12 months.

• Comment: Additionally, the authors should make it clear that they took the root biomass data from the previous study and estimated the C for these published values (BHC, BHF, and SCTA). Where primary data from a previous work were used to estimate C (e.g., Table 2), this should be mentioned in the table header.
  Response: To address the reviewers' comment, we have included a clarification in the table headers regarding the use of root biomass data taken from the previous study by Medina (2016) and Medina et al. (2021). Specifically, it was noted that these data were converted into carbon content for this study. Additionally, it is specified that data for the BHC, BHF, and SCTA forests were obtained from secondary sources, while data for SBTA were based on primary information obtained through direct monitoring of this forest.

• Comment: Where different time periods have been used to collect data, mention this in the table and figure headers. For example, in Figure 1, presumably the data from 3 sites were combined over several years, while SBTA data are from only one year. Also, refer to Table 2. It is known that there are differences in leaf litter fall and flowering intensity across years in other mangrove regions.
  Response: To address this comment, we have explicitly mentioned in the titles of the tables and figures the different time periods used to collect data at the various study sites. Specifically, it is indicated that data for the BHC, BHF, and SCTA forests correspond to the period from 2012 to 2019, while data for the SBTA forest are from the single year of 2022. In the case of Figure 1 and Table 2, it is specified that data from the three sites (BHC, BHF, and SCTA) were combined over several years (2012-2019), while the data for SBTA correspond only to 2022. This clarification in the titles allows readers to understand the temporal variations in the data and how the variability in leaf litter fall and flowering, observed in other mangrove regions, may have influenced the results.

• Comment: Figures 1 a/b could be combined with Figure 2 to make 3 vertical panels for easier comparison in the following order: a) Total, b) Species, then c) Components.
  Response: However, we believe this figure should remain separate as it clearly illustrates the proportion of components in leaf litter fall and the total values.

• Comment: Why is there no value for basal area for other species in Table 1?
  Response: The information analyzed for the BHC, BHF, and SCTA forests was taken from Medina (2016) and Medina et al. (2021), which focused on the most abundant and structurally significant species in these mangrove forests. These species were prioritized because they were considered the main contributors to the forest structure and biomass. The basal area values presented in Table 1 reflect the species most relevant to the study, whose data were essential for analyzing carbon content and ecological dynamics.

• Comment: Figure 1 – Use the terminology in English that was defined previously [limnetic (<0.5 PSU), oligohaline (0.5 to 5 PSU), mesohaline (5 to 18 PSU), polyhaline (18 to 30 PSU), euhaline (30 to 40 PSU), and hypersaline (> 40 PSU)]. There are similar errors elsewhere. Note that "leaf litter fall" is misspelled in the axes and labels.
  Response: The terminology in the graph was corrected to match the previously defined English terms. Instead of using terms in Spanish, the corresponding English terminology for the salinity categories was applied. This English terminology was used consistently in the graph to align with the definitions used in the text.

• Comment: The typographical error in the y-axis of Figure 1, where "leaf litter fall" was misspelled.
  Response: The typographical error where "leaf litter fall" was misspelled has been corrected. The word is now spelled correctly and appears consistently in the figure.

• Comment: Figure 3 – Use the same terminology as in Line 100, "wet season" instead of "rainy season." Do the same in the text.
  Response: The terminology was adjusted as requested. The term "rainy season" was replaced with "wet season" in Figure 3 and throughout the text to maintain consistency with the terminology used in Line 100.

• Comment: The monthly analysis for SBTA (Table 5) was conducted as this site was sampled for only one year. This analysis seems isolated, and I recommend excluding it unless a monthly analysis for the other sites is performed to allow meaningful comparison of seasonal drivers. The explanation for Figure 5 is not very clear. Explain in more detail how the lag effect was identified, its duration, and significance. The exploration of a "direct relationship between salinity and root production" seems to be missing from the results. Why is this not shown in comparison with C in leaf litter fall in Figure 5?
  Response: Figure 5 and its analysis were removed to avoid misinterpretation. For the SBTA forest, since only 2022 data were available, it was not possible to perform the correlation analysis between monthly leaf production and salinity and climatic variables as initially planned. Therefore, no correlation models could be constructed for this forest, and the analysis was limited to the available data.

• Comment: I am not sure the two appendices add value to the article. Appendix 2 has already been mostly published. It is enough to direct the reader to previous works and distill key points in the discussion.
  Response: The appendices were removed, and the corresponding references were cited in the document to avoid repeating what has already been published.

• Comment: The conclusions could focus more on the importance of the findings and areas where future research efforts would be productive.
  Response: The conclusions were revised with the understanding that the extremes and persistence of salinity in the soil can serve as valuable indicators of root and leaf production in mangroves, while also acknowledging that factors beyond salinity contribute to explaining the mechanisms that drive carbon flow and accumulation.

• Comment: Minor edits: Add the unit of measure in Line 109, Lines 133-134 should define the terms when they are first mentioned, Line 301 the 6 decimal points for p are excessive, remove Lines 397-399. Check minor errors such as "mean ± EE" (Line 235), "mean ± SE" (Line 252), "mean ± ES" (Line 256).
  Response: The errors were corrected by adding the unit of measure in Line 109 as requested. We are not completely sure about this comment. The definition mentioned in Lines 133-134 was already given when it was first introduced. If there is any ambiguity or further clarification needed, we are willing to address it. The number of decimal places for the p-value in Line 301 was corrected. The minor errors related to "mean ± EE" (Line 235), "mean ± SE" (Line 252), and "mean ± ES" (Line 256) were fixed.

Author Response File: Author Response.pdf

Round 2

Reviewer 3 Report

Comments and Suggestions for Authors

Regarding my comment on the review, it is noted that the authors have clearly and objectively addressed my comments regarding the manuscript.

I therefore recommend my acceptance of the manuscript.

Author Response

Thank you for your comments and recommendations. We remain attentive to the next steps.

Reviewer 4 Report

Comments and Suggestions for Authors

There are several areas that have not been adequately attended to in my opinion.

Please check again the terminology: Figures 2 & 3 change hiperhaline to hyperhaline

• Comment: There is a need for more data on the C cycle in mangrove communities in different habitats. This study makes a useful contribution by exploring the annual C content in leaf litter and root growth cores in communities growing across a wide range of salinity. One of the weaknesses of the study is that one site was sampled for only one year, and this did not align with the sampling period of the other three sites. There is reuse of some root data (to estimate C content) from Reference 13, but I cannot determine if there is any overlap with Reference 31, as the citation is incomplete.
  Response: The secondary information used was based on a doctoral thesis [31] and an article stemming from that thesis [13]. Although the sampling years of the references differ from the primary data used, the inclusion of the SBTA forest in this study allows for addressing the influence of salinity on mangrove forests with contrasting salinity levels and structural development, reinforcing the consistency and validity of the data used to estimate carbon content in the roots. Although the results for SBTA are based on production data found in 2022, this temporal variability does not diminish the inclusion of this site in the study. By adding a forest with distinct ecological and structural characteristics, the study provides a more comprehensive view of how salinity influences the carbon cycle in mangroves. The use of annual averages for different habitats (BHC, BHF, and SCTA) allows for a coherent comparison between them, despite the temporal differences in sampling.

1. THIS EXPLANATION IS VERY HELPFUL TO THE READER AND THE SALIENT POINTS SHOULD BE INCLUDED IN THE MANUSCRIPT SO THE READER IS AWARE OF WHAT DATA WERE USED, AND THE SOURCE OF THESE DATA.

• Comment: Section 1 – Provide more background to the study before stating the objectives. For example, in the previous paper, the authors found a relationship between total and fine root biomass and PSU. So, this is not a new working hypothesis. How does the current study build on those observations?
  Response: In the previous paper, the authors found a significant relationship between total and fine root biomass and PSU, suggesting that salinity could have a direct impact on the development and structure of roots in mangrove communities. The current study builds on these previous observations by delving deeper into understanding how salinity affects not only root biomass but also the carbon cycle in mangrove communities. Instead of exploring a new hypothesis, this study extends already established relationships by analyzing the annual carbon content in leaf litter and internal roots of mangroves in habitats with contrasting salinities.
• 2. USEFUL EXPLANATION TO THE READER. I COULD NOT FIND ANY ADDITIONAL INFORMATION IN THE REVISED MANUSCRIPT. IT MUST BE ADDED INTO THE INTRODUCTION.
• Comment: Section 2.2 – Provide a brief reason why the number of plots differs between sites.
  Response: This study is partly based on secondary information from Medina (2016) and Medina et al. (2021), and the SBTA forest was included as an additional site. The number of plots in SBTA differs from those in the other forests due to specific access conditions for that site, which limited the number of plots that could be sampled compared to the other forests.
• 3. INCLUDE AN EXPLANATION IN THE METHODS OF THE PRIMARY AND SECONDARY DATA. FIGURE 2 REFERS TO THE SECONDARY DATA, BUT THE INFORMATION IS NOT READILY AVAILABLE AND A STATEMENT ON THE CAPTURE OF THE SECONDARY DATA IN RELATION TO THE PRIMARY DATA SHOULD BE INCLUDED HIGHLIGHTING THE DIFFERENT SAMPLING TIMES, SAMPLING LOCATION & SAMPLING INTENSITY.

Author Response

• Comennt 1. There are several areas that have not been adequately attended to in my opinion.

Please check again the terminology: Figures 2 & 3 change hiperhaline to hyperhaline

Response:  The term 'hyperhaline' was adjusted in the figures.

• Comment  2,  2 round: THIS EXPLANATION IS VERY HELPFUL TO THE READER AND THE SALIENT POINTS SHOULD BE INCLUDED IN THE MANUSCRIPT SO THE READER IS AWARE OF WHAT DATA WERE USED, AND THE SOURCE OF THESE DATA.

Response 2, 2 round: In response to the comment, a paragraph describing the sampling design has been included in the methodology section. This addition helps clarify the data used and their sources, as suggested, and provides important context for the reader.

Comment 3, round 2:  USEFUL EXPLANATION TO THE READER. I COULD NOT FIND ANY ADDITIONAL INFORMATION IN THE REVISED MANUSCRIPT. IT MUST BE ADDED INTO THE INTRODUCTION.

Response 3, round 2 Thank you for your observation. As recommended, the explanation regarding the connection between salinity, root biomass, and the carbon cycle has now been incorporated into the Introduction section of the revised manuscript. This addition aims to provide the reader with a clearer understanding of the background and rationale for this study, as well as the relevance of previous findings that support the current research focus.  

• Comment 4. INCLUDE AN EXPLANATION IN THE METHODS OF THE PRIMARY AND SECONDARY DATA. FIGURE 2 REFERS TO THE SECONDARY DATA, BUT THE INFORMATION IS NOT READILY AVAILABLE AND A STATEMENT ON THE CAPTURE OF THE SECONDARY DATA IN RELATION TO THE PRIMARY DATA SHOULD BE INCLUDED HIGHLIGHTING THE DIFFERENT SAMPLING TIMES, SAMPLING LOCATION & SAMPLING INTENSITY.

Response: Thank you for the comment. This recommendation has already been addressed: the distinction between the primary and secondary data, including their respective sampling times, locations, and sampling intensity, is clearly detailed in the sampling design section and is also reflected in the corresponding figures and tables. We believe that with these clarifications, readers can adequately understand the characteristics and differences between both datasets.

Author Response File: Author Response.docx

Round 3

Reviewer 4 Report

Comments and Suggestions for Authors

Please amend the word Hiperhalyne in Figures 2 and 3 (in the bodies of these figures)