The Impact of Plant Spatial Patterns on Nitrogen Removal in the Naolihe Wetlands of Northeast China

Round 1

Reviewer 1 Report

The authors performed a detailed investigation on the topic “The Impact of Plant Spatial Pattern on Nitrogen Removal in Water in Naolihe Wetlands in Northeast China.” Using Naolihe wetlands as the study area, the authors observed the removal rates of three forms of Nitrogen (TN, NH₄-N and NO₃-N) from water. They noted that the main force of nitrogen removal was dependent on plants with the largest areas. However, the fragmentation of all plant patches resulted in a decrease in the nitrogen removal ability. The research work was detailed and quite impressive. However, minor language corrections are required before publishing. And there are some suggested revisions the authors can consider before publication.  Specific comments are as follows

1.      The authors mentioned that the “alkaline potassium persulfate digestion-UV spectrophotometric method was used to determine the TN concentration of the samples; however, it would be important to cite the literature and briefly describe the process.

2.      The authors reported the impact of the patch area but did not clearly state how the patch area was calculated or determined. They also report the impact of patch fragmentation but give no image or illustration of the different fragmentations of plants. Similarly, they observed the impact of plant shape but there is no depiction or illustration about the different shapes of plants in this study. Kindly provide these missing details.

Page 2: Kindly revise “ The many studies” to “Several Studies.

Page 2: Kindly revise “removal nitrogen in water” to “remove nitrogen in water”

Page 2: Kindly revise “The main scientific problems to be solved in this study are as follows:” to “The objectives of this study are as follows:”

There are several grammatical and language errors, the authors are encouraged to check and if possible employ the service of a native speaker.

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

The review of the manuscript entitled: “The Impact of Plant Spatial Pattern on Nitrogen Removal in Water in Naolihe Wetlands in Northeast China”. The work is interesting and well-written. By responding to the following comments and questions, the work can be ready for publication:

1.      The main question is about the case study. Can we use the results obtained in this manuscript in other regions? This point should be discussed in the revision stage.

2.      Also, there is a limitation of time in the used data. Please consider it.

3.      In the abstract, the authors mentioned the obtained results. But why exactly they observed these results is unclear. Please clarify it.

4.      Please briefly review the most important methods of nitrogen removal.

5.      What were the criteria for the method of removal?

6.      It is recommended to mention the effect of water on organic material deposition in the introduction section. For this purpose, the next references can be used in the revision stage. https://doi.org/10.1080/10916466.2022.2049819

7.      Please translate the information in Figure 1 from Chinese to English.

8.      Did the authors determine the ionic components and TDS of the used water sample? If it is available, please add them.

9.      Please improve the quality of Figure 2.

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

The authors observed spatial pattern of wetland plants on nitrogen removal in a river and highlight the positive correlation between the connectivity within plant patches and the nitrogen removal ability. I recommend it to be published after revision.

Specific comments:

-Title: Too many “in”. Change to “Impact of Plant Spatial Pattern on Surface Water Nitrogen Removal in Naolihe Wetlands of Northeast China”.

-Abstract: In addition to result description, more key data are recommended to be added.

-Introduction:

1^st and 2nd paragraphs: Cases out of China should be reviewed to better explain the global applicability.

4th paragraph: Change “scientific problems to be solved” to “objectives”.

-Materials and Methods: A location graph of sampling area could be useful in the text, in addition to the GPS coordinates in Table S1.

2.1 Study area: “Carex appendiculata” can be abbreviated as “C. appendiculata”.

Figure 1: Replicated information can be observed for the subgraphs. Chinese characters should be translated in to English.

2.2. Water sampling and determination: Why only two seasons were surveyed?

2.3. Remote sensing interpretation and spatial indices extraction: All abbreviations of Figure 2 should be fully written in the figure captions when firstly occurred. The description of Figure 2 should be moved to Results section.

-Results and discussion:

3.1. The effect of plant area on nitrogen removal: The chemical valences of NO3 and NH4 should be added in the upper right corners, both in the text and in the figures.

3.2. The effect of plant shape on nitrogen removal: Change “plant shape” to “plant patch shape”.

-Discussion:

4.1. The particularity of floating leaf plants: Unclear. Why the drainage with nitrogen species needs to pass through floating leaf plants and then proceed to other plants distribution areas?

4.3. The collaborative effects of wetland plants on nitrogen removal: “the wetland needs to expand 2.87 times its original area along the direction perpendicular to water channel” and "the wetland needs to expand 2.62 times along the direction of water channel", these interesting computational inference need further discussion on their practical efficiency.

-Conclusions:

Compared to the previous research objectives, change the stacking of results to more conclusive statements.

The language need further improvement to be clearer. 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

The authors have revised it as requested. It can be accepted.

Reviewer 2 Report

The work was revised based on the comments. So it is ready for publication.