Community Structure and Soil Mineral Concentration in Relation to Plant Invasion in a Subtropical Urban and Rural Ecotone
Round 1
Reviewer 1 Report
The manuscript by Xie et al. titled ‘Community structure and soil mineral concentration regulate plant invasion in a subtropical urban rural ecotone’ seeks to untangle the relationships between community structure and soil mineral concentrations and their role in regulating plant invasions in a subtropical urban forest. The authors utilize vegetation inventories, soil nutrient and structural data as well as a variety of analytical approaches to untangle the relationship between habitats and patterns in invisibility. The authors reveal significant differences in concentrations of soil minerals between sites as well as differences in cover which provide insight into the potential invasibility and stability of the habitats. The authors undertake a thoughtful analysis of the data untangling background differences between sites and investigating how differential cover and vegetation at each site may impact invasibility. My biggest concern however is that without a chronosequence approach or a repeated measures design the results may reflect more site history/site prep associated with land use history and propagule pressure from surrounding areas more so than the ability for a community assemblage to repel invasives. Overall however, the manuscript was well written and will be a useful contribution to the literature.
I hope the comments provided below can be used to enhance the manuscript and reflect my general interest in the field and not a critique.
Line 18: Italicize Latin names throughout
Line 27: Define CCA, its first used here.
Line 41-42: Your article is about plant invasions, it’s not clear from this sentence if you are discussing alien plant invasions or other pest/pathogen invasions. Perhaps make this distinction here?
Line 60-61: when you discuss similarity between an alien invader and a native plant, are you referring to functional similarity or something else?
Line 72: What do you mean by difference in appearance? Do you mean structure, functional type?
Line 88-89: perhaps reword this sentence. The ecotones are threatened with urban and industrial pollution, not the factories.
Line 95-96, no need to capitalize Abandoned fallows or Natural and Planted forests.
Line 150-152: Provide appropriate references so a reader could track down the equations you used to calculate these parameters.
Line 192, Table 3: Update caption to define variables T, A, and p.
Line 195: I’m not sure you have adequately discussed what the Indicator Value is. If you could ensure that this is discussed here, in the methods or previously that may be helpful for a naïve reader.
Line 197: Be careful with how you frame the discussion of high indicator values. You suggest that the species is ‘best adapted to local environmental conditions’, which fundamentally I agree with, however its possible that its associated with propagule pressure, site prep, or some pre-existing site conditions.
Line 210 and elsewhere: you should refer to forests not forest. Since you studied treatments across forests.
Line 292, Figure 6: Consider changing the axes to cumulative instead of accumulative? Also consider changing the axes to max of 100.
Line 322: report test statistic.
Line 338: This sentence reads a little strange. Its not sure what you mean by ‘the quadrants had similar habitat preferences’. The quadrants you are referring too are generated based on input variables, they represent variables that are closely correlated. They themselves are not habitat preferences, however the plants that reside in these ecosystems share similar habitat requirements as revealed by your analyses.
Line 366-68: It’s a bit unclear what you mean by this sentence, particularly by ‘full use’. Are you suggesting that these invasive species specifically are more capable of scavenging limiting resources relative to natives? If not, I’m not sure this sentence is correct as many species have different abilities to scavenge nutrients and different nutrient requirements.
Line 378-80: If there were marginal differences in height and cover in classes >3, wouldn’t it reinforce that the proliferation of invasives impacts recruitment (not an inherent structural component?).
Line 382-385: Consider rewording this sentence. Plant growth characteristics paired with competition govern individual plant structure (i.e. the cover a plant produces). The concept/phrasing of ‘plants with different cover…’, seems a bit strange, I think you are referring to growth strategy (fast/ early successional v. slow/late successional/shade tolerant).
Author Response
Response to Reviewer 1 Comments
Dear reviewer,
I am very grateful to your comments for the manuscript . Your comments are helpful for us to revise our manuscript. We have revised and corrected the manuscript. Below is our point-by-point response to your comments. Thank you again for your help.
Kind regards
Peiyun Xie
Line 18: Italicize Latin names throughout
Response: Thank you for your suggestion. We have italicized all the scientific names of plant species.
Line 27: Define CCA, its first used here.
Response: Thank you for your reminder. We have added a definition, please refer to line 27 for details.
Line 41-42: Your article is about plant invasions, it’s not clear from this sentence if you are discussing alien plant invasions or other pest/pathogen invasions. Perhaps make this distinction here?
Response: Thank you for your question. We agree, and have rewritten this sentence accordingly.
Line 60-61: when you discuss similarity between an alien invader and a native plant, are you referring to functional similarity or something else?
Response: Thank you for your question. We are referring to functional similarity. I have corrected it.
Line 72: What do you mean by difference in appearance? Do you mean structure, functional type?
Response: Thank you for your question. We use appearance for the composition, structure and lifestyle of the vegetation on the ground.
Line 88-89: perhaps reword this sentence. The ecotones are threatened with urban and industrial pollution, not the factories.
Response: Thank you for your suggestion. Your statement is more accurate than ours and so we have modified the text accordingly, please refer to lines 92-93 for details.
Line 95-96, no need to capitalize Abandoned fallows or Natural and Planted forests.
Response: Thank you for your suggestion. We have checked and changed to lower case in all cases.
Line 150-152: Provide appropriate references so a reader could track down the equations you used to calculate these parameters.
Response: Thank you for your suggestion. We have added the relevant reference, please refer to line 157 for details.
Line 192, Table 3: Update caption to define variables T, A, and p.
Response: Thank you for your question. We have added descriptions in both the methods and results section, please refer to lines 164-167, and 206-208 for details.
Line 195: I’m not sure you have adequately discussed what the Indicator Value is. If you could ensure that this is discussed here, in the methods or previously that may be helpful for a naïve reader.
Response: Thank you for your suggestion. We have added the relevant reference and formula, please refer to lines 169-175 for details.
Line 197: Be careful with how you frame the discussion of high indicator values. You suggest that the species is ‘best adapted to local environmental conditions’, which fundamentally I agree with, however its possible that its associated with propagule pressure, site prep, or some pre-existing site conditions.
Response: Thank you for your suggestion. We have changed the text accordingly, please refer to lines 214-215 for details.
Line 210 and elsewhere: you should refer to forests not forest. Since you studied treatments across forests.
Response: Thank you for your suggestion, we have replaced “forests” with “forest”, please refer to line 230 for details.
Line 292, Figure 6: Consider changing the axes to cumulative instead of accumulative? Also consider changing the axes to max of 100.
Response: Thank you for your suggestion. We have changed the axes to cumulative instead of accumulative and to a maximum value of 100, please refer to Figure 6.
Line 322: report test statistic.
Response: Thank you for your suggestion. We have added test statistic, please refer to line 345 for details.
Line 338: This sentence reads a little strange. Its not sure what you mean by ‘the quadrants had similar habitat preferences’. The quadrants you are referring too are generated based on input variables, they represent variables that are closely correlated. They themselves are not habitat preferences, however the plants that reside in these ecosystems share similar habitat requirements as revealed by your analyses.
Response: Thank you for your suggestion. We have modified the text to better reflect that. Please refer to lines 361-362 for details.
Line 366-68: It’s a bit unclear what you mean by this sentence, particularly by ‘full use’. Are you suggesting that these invasive species specifically are more capable of scavenging limiting resources relative to natives? If not, I’m not sure this sentence is correct as many species have different abilities to scavenge nutrients and different nutrient requirements.
Response: Thank you for your question. Yes, on reflection ‘full use’ is inappropriate in this sentence. We have modified the text accordingly, please refer to lines 393-394 for details.
Line 378-80: If there were marginal differences in height and cover in classes >3, wouldn’t it reinforce that the proliferation of invasives impacts recruitment (not an inherent structural component?).
Response: Thank you for your question. Our study was based on survey observations of three understory communities. The numbers of seedlings with coverage class < 3 were greater in the slightly invasive communities than in the seriously invasive communities, indicating that native plants may affect the invasion results during the seedling phase. Light resources may be the main limiting factor for invasive plants in the study area. The ability of aliens to capture resources during the seedling phase is limited. However, a large number of native seedlings under natural and planted forests captured the light resources needed for the growth of aliens, so aliens rarely appeared. This may be one of the ways in which two communities can resist invasion. But it is not clear that plants with cover in classes >3 promote plant invasion. Therefore, more study in the future is needed to further explain these differences.
Line 382-385: Consider rewording this sentence. Plant growth characteristics paired with competition govern individual plant structure (i.e. the cover a plant produces). The concept/phrasing of ‘plants with different cover…’, seems a bit strange, I think you are referring to growth strategy (fast/ early successional v. slow/late successional/shade tolerant).
Response: Thank you for your suggestion. What I was trying want to express is that the richer cover class, the more fully utilized the resources.We have revised as suggested, please refer to line 411 for details.
Author Response File: 
Author Response.docx
Reviewer 2 Report
Dear authors,
Thank you for an interesting paper. The results of this research will have an impact on forest management and provide important information in ecology of invasive species in various type of ecosystems. Before the final acceptation of this manuscript, I have some comments and questions that might improve the quality of this manuscript.
- read the paper carefully again as it contains several wrong grammar spellings and mistakes.
- scientific names of plant species must be in italics. Correct it in the whole text.
- I miss a little information about native habitats of the invasive plants Mikania micrantha and Borreria latifolia. Please, add some important details.
- Even those two invasive species were mainly present in the Abandoned fallows understory (you state that average alien cover is 24,3%), I would know more. Did you detect other plant species? Please, give the reader brief and complete information about it.
- In the section results please specify what T, A and p means. Those abbreviations need some explanations. What do these values mean?
- How did you calculate indicator values? What this parameter show? This information should be in material and method part.
- In conclusion, the information that natural and planted forest were slightly invaded is not correct. According to Table 1, natural forest showed 0% average alien cover.
After considering all comments into the manuscript, I would recommend this paper to this journal. Good luck with your future research.
Author Response
Response to Reviewer 2 Comments
Dear reviewer,
Thank you for your time given to evaluating our manuscript. Your comments are helpful for us to revise our manuscript. We have revised and corrected the manuscript. Below is our point-by-point response to your comments. Thank you again for your help.
Kind regards
Peiyun Xie
Reviewer #2
- Read the paper carefully again as it contains several wrong grammar spellings and mistakes.
Response: Thank you for your suggestion. We have checked and corrected the grammatical and spelling errors.
- Scientific names of plant species must be in italics. Correct it in the whole text.
Response: Thank you for your suggestion. We have italicized all the scientific names of plant species.
- I miss a little information about native habitats of the invasive plants Mikania micrantha and Borreria latifolia. Please, add some important details.
Response: Thank you for your suggestion. I have added a new table of invasion of different stand types, as detailed in supplementary materials table S1.
- Even those two invasive species were mainly present in the Abandoned fallows understory (you state that average alien cover is 24,3%), I would know more. Did you detect other plant species? Please, give the reader brief and complete information about it.
Response: Thank you for your suggestion. Related information is now included, as detailed in supplementary materials table S1.
- In the section results please specify what T, A and p means. Those abbreviations need some explanations. What do these values mean?
Response: Thank you for your question. We have added descriptions in both the methods and results section, please refer to lines 164-167,and 203-208 for details
- How did you calculate indicator values? What this parameter show? This information should be in material and method part.
Response: Thank you for your suggestion. We have added the relevant reference and formula. Please refer to lines 168-175 for details.
- In conclusion, the information that natural and planted forest were slightly invaded is not correct. According to Table 1, natural forest showed 0% average alien cover.
Response: Thank you for your suggestion. We found only one invasive plant in the natural forest. I have revised it, please refer to table 1.
Author Response File: Author Response.docx
