Nitrogen Influence to the Independent Invasion and the Co-Invasion of Solidago canadensis and Conyza canadensis via Intensified Allelopathy
, Zhongyi Xu 1, Daolin Du 1,2,* and Congyan Wang 1,2,3,*
Round 1
Reviewer 1 Report
Dear authors, the presented study is very important and advances current knowledge regarding plant invasions.
I have some suggestions for manuscript improvement prior to the acceptance.
The title should not be speculative, please consider changing it to 'Nitrogen influence to the independent invasion and the co-invasion of Solidago canadensis and Conyza canadensis via intensified allelopathy'
Line 12: The unbold
Line 15 and onward: Asteraceae italic
Lines 51 and 54 are repeated in lines 68 to 72, please delete duplicates.
Why did you choose Lactuca as a species for this investigation? Is it the economically most important vegetable in the state/region? Is there any prior research on the same species so you wanted to broaden the knowledge?
Lines 93-102 do not belong to the material and methods section.
Lines 113 and 116 are repeated in lines 131 to 134, please delete duplicates..
Lines 148-157, please add SI measuring units.
Generally, throughout the results section, maximal and minimal values mentioned would be beneficial. The same strict style written in the results section is difficult to follow without the feeling that the reader is not moving through the manuscript stuck in the one same sentence, please consider rewriting the entire section.
Lines 190 - 204 are written almost as copy-paste please rephrase them.
Chapter 3.3 the same comment.
3.4. Differences in the effects of the two alien plants treated with different types of nitrogen - this section refers to already stated results, maybe it should be rephrased and placed in the discussion section.
Line 387: The chief issue correct to The major issue
Author Response
The response to the comments of Reviewer 1:
Dear authors, the presented study is very important and advances current knowledge regarding plant invasions. I have some suggestions for manuscript improvement prior to the acceptance.
Answer: We are grateful to the anonymous reviewer for the precious comments that greatly improved this manuscript. Based on the insightful comments, we have made the corresponding changes, and the changed contents in the text have been tagged in blue in the corrected version of this manuscript. Please check it. Many thanks!
The title should not be speculative, please consider changing it to 'Nitrogen influence to the independent invasion and the co-invasion of Solidago canadensis and Conyza canadensis via intensified allelopathy'
Answer: The title has been revised in the corrected version of this manuscript accordingly [please see lines 2-4 (page 1)]. Please check it.
Line 12: The unbold
Answer: The format of this word (the) has been revised in the corrected version of this manuscript accordingly [please see line 12 (page 1)]. Please check it.
Line 15 and onward: Asteraceae italic
Answer: The format of this word (Asteraceae) has been changed throughout the corrected version of this manuscript accordingly. Please check it.
Lines 51 and 54 are repeated in lines 68 to 72, please delete duplicates.
Answer: The paragraph (Consequently, it is important to evaluate the combined allelopathy on the seed germination and seedling growth of adjacent species facilitated by two Asteraceae alien plants that co-invade the same habitat to study the mechanism that underlies the co-invasion of two alien plants in more detail.) has been removed in the corrected version of this manuscript accordingly to avoid duplication [please see line 50 (page 2)]. Please check it.
Why did you choose Lactuca as a species for this investigation? Is it the economically most important vegetable in the state/region? Is there any prior research on the same species so you wanted to broaden the knowledge?
Answer: The reason choose lettuce as a species for this investigation includes the following:
(1) lettuce is commonly used in bioassays for allelopathy due to its sensitivity to external environment stresses (including allelochemicals).
(2) lettuce is one of the more common cultivated vegetables in the areas invaded by the two alien plants (Solidago canadensis and Conyza canadensis) and is also affected by atmospheric nitrogen deposition.
(3) the two alien plants and lettuce can coexist in the same ecosystem (particularly farmland, wasteland, and roadsides) in South Jiangsu, China.
(4) the two alien plants and lettuce all belong to the Asteraceae family, which comprises the largest number of alien plants in China at the family level. A total of 92 alien plants in the Asteraceae currently grow in China. They comprise approximately 17.86% of the total species number of alien plants at the family level in China.
Meanwhile, the contents have been added in the corrected version of this manuscript accordingly [please see lines 84-89 (page 2)]. Please check it.
Is there any prior research on the same species so you wanted to broaden the knowledge?
Answer: In our earlier study (Wei, M.; Wang, S.; Wu, B.D.; Cheng, H.Y.; Wang, C.Y. Combined allelopathy of Canada goldenrod and horseweed on the seed germination and seedling growth performance of lettuce. Landsc. Ecol. Eng. 2020, 16, 299‒306. https://doi.org/10.1007/s11355-020-00421-y), we analyzed the individual and combined allelopathy of Solidago canadensis and Conyza canadensis on the seed germination and seedling growth of the horticultural Asteraceae species Lactuca sativa.
In addition, this previous study has been cited in this manuscript. Please check it.
Lines 93-102 do not belong to the material and methods section.
Answer: The paragraph has been inserted in the introduction section in the corrected version of this manuscript accordingly [please see lines 73-89 (page 2)]. Please check it.
Lines 113 and 116 are repeated in lines 131 to 134, please delete duplicates.
Answer: The sentence (The aqueous leaf extracts of the two alien plants included the following four types, i.e., control, leaf water extract of Canadian goldenrod, leaf water extract of horseweed, and a mixture of the aqueous leaf extracts of both plants in equal proportions (i.e., 1:1).) has been deleted in the corrected version of this manuscript accordingly to avoid duplication [please see line 112 (page 3)]. Please check it.
Lines 148-157, please add SI measuring units.
Answer: The units of the indicators have been added in the corrected version of this manuscript accordingly [please see electronic supplementary materials-Table S1]. Please check it.
Generally, throughout the results section, maximal and minimal values mentioned would be beneficial. The same strict style written in the results section is difficult to follow without the feeling that the reader is not moving through the manuscript stuck in the one same sentence, please consider rewriting the entire section.
Answer: The contents of the results section have been revised in the corrected version of this manuscript accordingly [please see lines 164-384 (pages 4-12)]. In particular, the percentage of increase or decrease has been added in the corrected version of this manuscript accordingly [please see lines 164-335 (pages 4-11)]. Please check it.
Lines 190 - 204 are written almost as copy-paste please rephrase them.
Answer: The second paragraph has been removed in the corrected version of this manuscript accordingly to avoid duplication [please see line 194 (page 4)]. Please check it.
Chapter 3.3 the same comment.
Answer: The contents of chapter 3.3 consist of four parts, which are the differences in effects of the two alien plants treated with the same type of nitrogen (NO3-N, NH4-N, CO(NH2)2-N, and mixed nitrogen in order). Therefore, there is no real repetition in this section. Please check it. Many thanks.
3.4. Differences in the effects of the two alien plants treated with different types of nitrogen - this section refers to already stated results, maybe it should be rephrased and placed in the discussion section.
Answer: The contents of chapter 3.1: (1) the effects of the aqueous leaf extracts of the two alien plants compared with control. (2) the differences in effects of the individual and combined aqueous leaf extracts of the two alien plants.
The contents of chapter 3.2: the effects of the individual and combined aqueous leaf extracts of the two alien plants treated with different types of nitrogen compared with control.
The contents of chapter 3.3: the differences in the effects of different types of aqueous leaf extracts treated with the same type of nitrogen (NO3-N, NH4-N, CO(NH2)2-N, and mixed nitrogen in order).
The contents of chapter 3.4: the differences in the effects of the same type of aqueous leaf extracts (Canadian goldenrod, three, and the extract mixture in order) treated with different types of nitrogen.
Therefore, the content of this section (chapter 3.4) is not repeated. Many thanks.
Line 387: The chief issue correct to The major issue
Answer: “The chief issue” has been revised to “The major issue” in the corrected version of this manuscript accordingly to avoid duplication [please see line 404 (page 13)]. Please check it.
We are very grateful to the anonymous reviewer for the insightful comments that greatly improved this manuscript.
Author Response File: 
Author Response.docx
Reviewer 2 Report
The manuscript entitled “Nitrogen may be beneficial to the independent invasion and the co-invasion of Solidago canadensis and Conyza canadensis via intensified allelopathy presents a very good insight to complexities of allelopathy.” describes and highlights an important issue of recent ecological concern. Allelopathy, can be used as a great tool for farmers and ecologists alike once fully understood. The synergistic effect of two alien plants highlighted in this manuscript can attract the reader. The manuscript is written very well, and needs very little improvements.
Overall, I appreciate the authors for such valuable efforts and performance quality. However, in addition to the above concerns, I highlighted some changes in different sections of the manuscript, which may aid in improving quality.
Title: Title needs improvement as it is too long and vaguely worded, please be specific and concise.
Abstract:
The abstract is well written, a little refining needed for the following lines.
- Line 17: Nitrogen form, can you this sentence be reworded, as the reader will have no clue what form means in this context, especially if he is reading from the start.
- Line 26-27: Please rewrite this part of the abstract. Too generic end while this statement is not linked with the actual conclusion of the manuscript.
Introduction
The introduction is written very well, good literature and citation has been used. I would only suggest the following minor changes.
- Line 39: The Asteraceae contains
- Line 53: broken language, please rewrite this and the preceding sentence.
- Line 78-86: Hypothesis 1 and 4, are they not too similar? Can they be combined into one?
Material and methods
Good use of scientific language, I have the following suggestions
- Line 93: source of this information?
- The first paragraph is more suitable for introduction than material and methods.
-Line 107: at 20 g of 20 g?
- Line 113: why 4 degree C? any reasons?
- Line 141-144 Is this a standard methodology, if yes, what is the source?
Results
Good language and great result data.
Discussion
- Line 369: minor language issue.
- Line 378: The finding is identified…. Rephrase the sentence please.
- Line 395: how can the leaves be mixed in the same location? Probably language issue here.
- Line 473-474: Can something related to the possible impact of allelochemicals in vivo be added? As in vivo, plants are under influence of multiple abiotic and biotic factors, which might effect the allelochemicals activity.
Author Response
The response to the comments of Reviewer 2:
The manuscript entitled “Nitrogen may be beneficial to the independent invasion and the co-invasion of Solidago canadensis and Conyza canadensis via intensified allelopathy presents a very good insight to complexities of allelopathy.” describes and highlights an important issue of recent ecological concern. Allelopathy, can be used as a great tool for farmers and ecologists alike once fully understood. The synergistic effect of two alien plants highlighted in this manuscript can attract the reader. The manuscript is written very well, and needs very little improvements.
Overall, I appreciate the authors for such valuable efforts and performance quality. However, in addition to the above concerns, I highlighted some changes in different sections of the manuscript, which may aid in improving quality.
Answer: We are grateful to the anonymous reviewer for the valuable comments that improved this manuscript greatly. We have made the related corrections according to the constructive comments recruited by the reviewer, and the modified parts in the text have been marked in blue in the corrected version of this manuscript. Please check it. Thanks a lot!
Title: Title needs improvement as it is too long and vaguely worded, please be specific and concise.
Answer: The title has been revised to “Nitrogen influence to the independent invasion and the co-invasion of Solidago canadensis and Conyza canadensis via intensified allelopathy” in the corrected version of this manuscript accordingly [please see lines 2-4 (page 1)]. Please check it.
Abstract:
The abstract is well written, a little refining needed for the following lines.
- Line 17: Nitrogen form, can you this sentence be reworded, as the reader will have no clue what form means in this context, especially if he is reading from the start.
Answer: The sentence has been amended in the corrected version of this manuscript accordingly [please see lines 17-18 (page 1)]. Please check it.
- Line 26-27: Please rewrite this part of the abstract. Too generic end while this statement is not linked with the actual conclusion of the manuscript.
Answer: The sentence has been modified in the corrected version of this manuscript accordingly [please see lines 26-27 (page 1)]. Please check it.
Introduction
The introduction is written very well, good literature and citation has been used. I would only suggest the following minor changes.
- Line 39: The Asteraceae contains
Answer: “contain” has been revised to “contains” in the corrected version of this manuscript accordingly [please see line 39 (page 1)]. Please check it.
- Line 53: broken language, please rewrite this and the preceding sentence.
Answer: The paragraph has been removed in the corrected version of this manuscript accordingly to avoid duplication [please see line 50 (page 2)]. Please check it.
- Line 78-86: Hypothesis 1 and 4, are they not too similar? Can they be combined into one?
Answer: The meaning of hypothesis 1: the allelopathy of the mixture of extracts from the two alien plants may be higher than their individual extracts.
The meaning of hypothesis 4: the effects of nitrogen on the combined allelopathy of the two alien plants may be greater than the effects of nitrogen on the independent allelopathy.
Therefore, the two hypotheses (1 & 4) are not identical.
Moreover, the fourth hypothesis (the differences in the effects of nitrogen deposition on the combined allelopathy and the independent allelopathy) follows the second hypothesis (the effect of nitrogen deposition on the allelopathy) and the third hypothesis (the differences in the effects of different nitrogen types on the allelopathy) in this study.
Many thanks.
Material and methods
Good use of scientific language, I have the following suggestions
- Line 93: source of this information?
Answer: These three sentences have been cited the same references. Therefore, for the sake of ambiguity, all three sentences have been cited the references in the corrected version of this manuscript accordingly [please see lines 76-80 (page 2)]. Please check it.
- The first paragraph is more suitable for introduction than material and methods.
Answer: The paragraph has been placed in the introduction section in the corrected version of this manuscript accordingly [please see lines 73-89 (page 2)]. Please check it.
-Line 107: at 20 g of 20 g?
Answer: “at” has been changed to “of” in the corrected version of this manuscript accordingly [please see line 106 (page 3)]. Please check it.
- Line 113: why 4 degree C? any reasons?
Answer: If the solution is left at room temperature, it may deteriorate over time. If the solution is left in the refrigerator at -20 or -80 degrees Celsius, it will freeze and become unusable.
- Line 141-144 Is this a standard methodology, if yes, what is the source?
Answer: The references have been cited in the corrected version of this manuscript accordingly [please see line 143 (page 3)]. Please check it.
Results
Good language and great result data.
Answer: Many thanks.
Discussion
- Line 369: minor language issue.
Answer: The sentence has been revised in the corrected version of this manuscript accordingly [please see lines 386-387 (page 12)]. Please check it.
- Line 378: The finding is identified…. Rephrase the sentence please.
Answer: The sentence has been modified in the corrected version of this manuscript accordingly [please see lines 395-396 (page 12)]. Please check it.
- Line 395: how can the leaves be mixed in the same location? Probably language issue here.
Answer: The sentence has been amended in the corrected version of this manuscript accordingly [please see line 413 (page 13)]. Please check it.
- Line 473-474: Can something related to the possible impact of allelochemicals in vivo be added? As in vivo, plants are under influence of multiple abiotic and biotic factors, which might effect the allelochemicals activity.
Answer: The information has been added in the corrected version of this manuscript accordingly [please see lines 491-495 (page 14)]. Please check it.
Thanks for your precious comments that greatly improved our manuscript.
Author Response File: Author Response.docx
Round 2
Reviewer 1 Report
Thank you for the implemented changes.
Kind regards,
M.
