All reviews of published articles are made public. This includes manuscript files, peer review comments, author rebuttals and revised materials. Note: This was optional for articles submitted before 13 February 2023.
Peer reviewers are encouraged (but not required) to provide their names to the authors when submitting their peer review. If they agree to provide their name, then their personal profile page will reflect a public acknowledgment that they performed a review (even if the article is rejected). If the article is accepted, then reviewers who provided their name will be associated with the article itself.
Thanks for submitting your revised manuscript addressing my minor comments. I support publication of the revised manuscript.
Please correct Tables 1 and 2 during the proof stahe as they still us "plumbum" in the tables (should be "lead")
Thank you for your careful revision. I identified just a few remaining issues as follows:
1. In your response letter, you have provided a clear and valuable explanation of your index (I). However none of this information is provided to readers in your revised manuscript. (Lines 213-217). Could you please add a sentence in Methods listing the specific Fi and Wi that you used to calculate I?
2. I see that "lead" has been used in your revised table captions starting on Line 697. However, in the tables that were included in your revised manuscript PDF, the word "plumbum" is still present. Please be sure that these are changed to "lead".
3. Figure 3 x-axis labeling on graphs -- Please use italics for species names.
Thank you for addressing the reviewer comments. I have a few additional inquires. Furthermore, the manuscript contains many English language issues. I have edited English in the annotated PDF uploaded to the review system. Please check the annotated PDF. On the annotated PDF, I also added a couple comments on the Methods where clarification is needed.
Additionally, the following issues need to be addressed in the Tables and Figures:
Table 1 and Table 2 – the meaning of the “Area site” should be explained in the caption (C28, C1, etc.). Why not list the crops in table 1 next to the plot number? Replace “Plumbum” with “Lead”. Table 3 and Figure 4 and Table 4 – the term “Quick Available Phosphorus” has no recognized meaning in English. Either use standard terms such as “available phosphorus” or provide a clear definition of what you mean by “Quick Available Phosphorus”. I am not in favor of the latter option because that phase is grammatically incorrect. Following correct English grammar, the phrase would be “Quickly Available Phosphorus”.
Table 5 – Two columns on the right side have identical headings “Increase of average fertility per km2 /(kg/km2)” . How do these two columns differ? This needs to be explained in the caption or with a footnote on the table.
Table 5 -- I think these values are the projected/estimated increases in fertility based on your model adapted from Somura et al. 2015. In that case, the Table 5 caption should say “Projected” or “Estimated” improvement in fertility… Table 7 Where does the “Fertility degree” rating come from? This should be explained in the table 7 caption. The equation for the numeric value was given in the Methods, but the criteria for determining low versus medium versus high ratings should be clearly described.
The revised manuscript shows significant improvement, but some residual issues remain, both in presentation and logical alignment between data, modeling, and conclusions. Some attention to the following issues is required:
1. Language and Grammar
• Still contains awkward, ambiguous phrasing and redundancies. For example:
“The water quality was categorized as Class III-V…revealed that the region’s water quality was classified as mildly polluted.”
This is repetitive and unclear whether all plots were in Class V or some ranged from III to V.
• Incorrect or awkward constructions like “the availability of potassium was found to be notably high” are repeated without numerical backing or comparative discussion.
2. Overinterpretation
• The conclusion implies that remediation increased migratory bird populations, but no pre-treatment baseline or control data are provided for bird counts. It’s correlation, not proven causation.
• Soil fertility gains are attributed to bird droppings without fully isolating other contributors like crop type or previous fertilization.
3. Missing or Weak Controls
• The control plots are not adequately described. Were they completely unplanted? Fallowed? Previous-year crops? This limits interpretation of “improvement.”
4. Unclear Statistical Comparisons
• The manuscript mentions statistical significance but often doesn’t report p-values or confidence intervals in tables or figures. This weakens the modeling interpretation.
5. Logic Gaps
• The idea that improved soil fertility from bird droppings will “enhance crop productivity and attract more birds” is stated but not demonstrated. The feedback loop is speculative.
• The classification of Class III–V water as “mildly polluted” is inconsistent with Chinese water quality standards, where Class V is seriously polluted.
6. Model Limitations Not Addressed
• No sensitivity or uncertainty analysis for the bird-dropping-derived soil fertility model.
• Assumes uniform defecation rates and nutrient content across species and time, which is likely unrealistic.
One more revision will be require in tracking mode, along with co-author permissions.
The paper may be reconsidered after a major revision, addressing all of the detailed comments of the reviewers. Most noted a lack of detail and rigor in the descriptions and methodolology.
**PeerJ Staff Note:** Please ensure that all review, editorial, and staff comments are addressed in a response letter and that any edits or clarifications mentioned in the letter are also inserted into the revised manuscript where appropriate.
Literature references to be updated.
The article's structure needs to be improved.
The manuscript lacks a clear method description and a valid statistical approach.
Validity should be improved by adding more statistical analyses to support the discussion section.
Introduction
The introduction should be updated with references from 2024 (and maybe 2025).
Methods
137-154 – This description should be moved to the introduction section.
2.2. Construction of migratory bird habitat—rice field restoration—The authors should provide details on the construction models and methods applied. Moreover, they must detail the year of the experiment, the varieties used, and the cultivation approaches.
2.3. Observations of birds – It is not clear the experiment's timeline and the restored plant's developmental stage at the moment of the observation. I suggest adding a figure or a table to clarify these aspects.
L161 – Table 1 reports the water quality monitoring and statistics of single-factor results in dry conditions, not the experimental design. Do the authors refer to Table S1?
L167-202 – Add supporting references for methods or a detailed description with quantities and ratios. Also, provide the type of instruments used.
Results
The presentation of the results should not include the authors' point of view but rather a clear description of the data obtained. The repetition of methods should be avoided, and the additional details included in this section should be moved to the methods section.
Values in tables are presented with standard deviations and statistics. Statistics (e.g., comparison of the means and other tests) are also missing in the figures.
Table 1 and Table 2 – are the limit values linked to the regulatory framework or the LOD and LOQ of the method used?
Discussion
The discussion lacks relevance. It should be revised thoroughly after a correct statistical evaluation of the data.
L381-440 – Without additional analyses, it is impossible to directly correlate the presence of organic matter in the droppings (or to birds foraging and defecation ) with that of soil. The direct contribution is impossible, and many factors contribute to incorporating organic matter into soil structure. The authors should revise these statements.
402-411; 452-468 – This description suits a method section, not the discussion.
This paper is good, but it needs some improvements.
To give the present study a proper scientific base and justification, add more citations/references based on recent scientific research on the topic worldwide and in the region.
Please use the most recent references/citations for this paper.
Please check and improve the overall language of MS.
In the introduction section, add more information on recent research studies on wetland farmland and its implications on global and regional levels.
Add some case studies worldwide and in the region to highlight the significance of this current study, such as its impact on migratory birds and their populations.
What are the principal significances of this study? Please highlight.
What are the significant limitations of this study?
What are the new highlights and prospects of this current study?
Please add/ highlight the impacts on the local community.
Please add more models and water indices to make it more scientifically significant.
Strengthen the discussion section.
Add figures/photos for more paper illustrations in the study area and relevance.
What are the significant findings or highlights of this study? Please add on MS.
Improve the conclusion part with the significant outcome of the study.
Add a section before the conclusion containing future perspectives and recommendations from this current study.
Please add some photographs and a study area map.
Justify the overall water quality and soil health concerning wetlands with global and regional comparisons (other countries/Regions).
These will make the paper a good one and good to go for publication.
Best wishes
-
-
The paper is good but needs some improvement.
Abstract: It seems strange to open with citing oxygen production as the key benefits of wetlands. There are many ecosystem services they provide people desire. Your aim presented here is about trialling different crops to assess their impact on water quality, but the sentences leading up to that don't set the scene, I suggest rewording. I struggle to make sense of why crops are being planted in a "restoration" plots. If they were restoration plots, then wouldn't they be aiming to plant natural vegetation?
The manuscript is generally written in English but would benefit from a thorough language revision to improve clarity, grammar, and professionalism. Several phrases are awkwardly constructed or imprecise (e.g., “mild to moderately pollution”; “essential to production of Earth’s oxygen”), which detract from the article’s technical credibility. Clearer, more concise phrasing and consistent terminology - particularly around key concepts like “restoration,” “farmland,” and “wetland function” - are needed to ensure unambiguous communication. Adherence to standard academic expression and tone should be improved throughout to meet professional publishing standards. Also, fewer assumptions about reader knowledge need to be made; for example, the Chinese water classification system will not be known in detail by most readers.
The introduction covers a broad range of wetland restoration literature, with citations that provide useful context on restoration strategies and ecological outcomes. However, the field background is somewhat diffuse and would benefit from clearer organisation and tighter linkage to the specific aims of the study. The rationale for assessing crop-based restoration in a wetland context is not adequately justified, particularly in relation to existing ecological restoration frameworks. The study would be strengthened by a more explicit explanation of how planting crops aligns with the goal of enhancing habitat for migratory birds. Reference to more targeted prior work on agroecological or multi-functional land restoration would better situate the research in its disciplinary context.
The study addresses a relevant knowledge gap by examining how different crop types, when used in a post-rice restoration setting, influence soil fertility, water quality, and bird diversity within a wetland buffer zone. However, the rationale for selecting crops (e.g., colza, mustard, cabbage) over native vegetation requires further clarification. It is unclear how this approach aligns with conventional wetland restoration practices aimed at enhancing habitat for migratory birds. A stronger justification situating this strategy within a multi-functional restoration or agroecological framework would enhance the relevance and clarity of the research aim.
Sampling was conducted across eight crop treatments with replicated points and control plots, which suggests an effort toward methodological rigour. However, the experimental layout lacks detail on plot randomisation or spatial separation. With plots apparently located in close proximity, it is difficult to distinguish treatment effects from edge effects or spillover influences, especially for mobile species like birds. Additionally, no information is provided on baseline variation in soil properties such as texture, bulk density, or carbon content, which may confound treatment effects. The spatial scale of the experiment also appears limited relative to the objective of evaluating bird diversity, raising concerns about whether the study design is appropriate to address that aim.
Key methodological details are missing, limiting confidence in the robustness of the findings. For instance, it is unclear how often water samples were collected or under what conditions. Similarly, bird assessments are not described in sufficient detail - what survey methods were used, at what frequency, and by whom? These are essential to assess observational reliability. While bird monitoring is mentioned in the methods, no results are presented - this inconsistency should be addressed.
Finally, the manuscript lacks detail on statistical analyses. The discussion references trends in pollutant concentrations and changes across time, but no corresponding statistical methods are described. It remains unclear how trends were quantified, whether significance was tested, or what models were applied. This absence undermines confidence in claims made in the results and discussion and should be rectified by clearly describing the statistical approach used for all major outcomes.
The findings presented in the discussion appear to align with the study's stated objectives; however, due to insufficient methodological and statistical detail, their validity is difficult to appraise with confidence. While the authors suggest that the restoration project influenced water quality and soil fertility, particularly through nutrient contributions from bird droppings, the robustness of these conclusions is undermined by gaps in the reporting of sampling design, spatial replication, frequency of measurements, and statistical analysis. Without this information, it is not possible to determine whether observed differences are statistically significant, biologically meaningful, or attributable to the treatments rather than confounding factors.
Moreover, the discussion lacks a critical interpretation of how these findings fit into existing research on wetland restoration or multifunctional landscapes. The potential novelty of testing crops in a restoration context is not well developed, and the absence of a clear justification for this approach limits the broader relevance of the work. To meaningfully assess the study’s contribution, it would be necessary to clarify whether this represents a novel restoration strategy, a context-specific land-use compromise, or a replication of known approaches under local conditions. As currently reported, the findings are difficult to evaluate, and the implications for restoration practice or policy remain uncertain.
All text and materials provided via this peer-review history page are made available under a Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.