High Impacts of Invasive Weed Lantana camara on Plant Community and Soil Physico-Chemical Properties across Habitat Types in Central Nepal

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

1.      119 were recorded in non-invaded sites and 97 in L. camara invaded sites. What are the possible reasons? Support your results logically with the help of available literature.

2.      Additionally, 79 plant species were present in both non-invaded and invaded sites. What are the possible reasons? Support your results logically with the help of available literature.

3.      The number of herb species was high in non-invaded sites which decreased sharply compared to other life form in invaded sites. What are the possible reasons? Support your results logically with the help of available literature.

4.      The plant family Poaceae was represented by the highest number of plant species (22) followed by Asteraceae (17 species). What are the possible reasons? Support your results logically with the help of available literature.

5.      Forty species were only present in non-invaded plots or were completely absent from invaded plots. However, in rain trees, class 3 has the lowest value than classes 1, 2, and 4. What are the possible reasons? Support your results logically with the help of available literature.

6.      There were just eighteen species among these forty species that stood out. What are the possible reasons? Support your results logically with the help of available literature.

7.      In total species richness, Simpson and Shannon diversity index of invaded sites decreased by 36.84%, 11.84% and 40.21% respectively. What are the possible reasons? Support your results logically with the help of available literature.

8.      In pre-monsoon season, forest-edge comprised of high species richness, followed by fallow land and roadside, however in the monsoon season, the fallow land comprised of highest number of species followed by forest-edge and roadside respectively. What are the possible reasons? Support your results logically with the help of available literature.

9.      The soil nutrients were higher in invaded sites compared to non-invaded sites except available Potassium and soil pH in both pre-monsoon and monsoon season. What are the possible reasons? Support your results logically with the help of available literature.

10.  In total, the soil nutrients like soil organic carbon, total nitrogen and available phosphorus of invaded sites increased by 11.61%, 28% and 24.03% respectively. Regarding the habitat type total nitrogen, available phosphorus, available potassium and soil pH were higher in fallow land followed by forest-edge and roadside while the total soil organic carbon was highest in forest-edge and lowest in roadside. What are the possible reasons? Support your results logically with the help of available literature.

Conclusion

1.      Please rewrite conclusion which includes highlights of your results.

2.      What you recommend for future?

 

3.      What are the benefits of this study?

Comments on the Quality of English Language

Minor editing of English language required

Author Response

Response to Reviewer’s Comments.

We thank the reviewer for the constructive comments and suggestions. We have corrected and revised the manuscript accordingly. Here are the point-by-point responses to the comments.

Comment: 1.      119 were recorded in non-invaded sites and 97 in L. camara invaded sites. What are the possible reasons? Support your results logically with the help of available literature.

Response 1: This is the most important result of our study. We have mentioned that Lantana camara could restrict the amount and duration of light below its canopy [42, 43], might have produced soil chemistry and litter decomposition [45] that could inhibit other plant species from growing under their canopy. 

2. Additionally, 79 plant species were present in both non-invaded and invaded sites. What are the possible reasons? Support your results logically with the help of available literature.

Response2: Thank you for pointing out it. The sampling sites both invaded and non-invaded are close (50 m apart) and represent the same habitat, hence the likelihood of occurrence of similar species is high. However, in invaded sites they tend to inhibit the growth of other species. 

 

3. The number of herb species was high in non-invaded sites which decreased sharply compared to other life form in invaded sites. What are the possible reasons? Support your results logically with the help of available literature.

Response3: This is due to the similar impact as mentioned earlier in response 1.

4. The plant family Poaceae was represented by the highest number of plant species (22) followed by Asteraceae (17 species). What are the possible reasons? Support your results logically with the help of available literature.

Response 4: The sampling sites are forest-edge, fallow-land and roadside, and they relatively represent open space like grassland. Hence there are more grass species (Poaceae), because annual grasses are more opportunistic species

5. Forty species were only present in non-invaded plots or were completely absent from invaded plots. However, in rain trees, class 3 has the lowest value than classes 1, 2, and 4. What are the possible reasons? Support your results logically with the help of available literature.

Response 5: These forty species represent most of the native species, which were highly influenced by L. camara. Again, this is possibly related to canopy level radiation, soil chemistry.

6. There were just eighteen species among these forty species that stood out L. camara invasion. What are the possible reasons? Support your results logically with the help of available literature.

Response 6: Some native plant species are strong competitors and can effectively utilize resources such as light, water, and nutrients, making it difficult for invasive species to contend their spread.

 

 

7. In total species richness, Simpson and Shannon diversity index of invaded sites decreased by 36.84%, 11.84% and 40.21% respectively. What are the possible reasons? Support your results logically with the help of available literature.

Response 7: Our results indicated that the non-invaded sites comprised of higher richness and diversity of plant species compared to invaded sites in both pre-monsoon and monsoon season, this could be due to competitive exclusion (Vila & Weine, 2004), altered habitat structure (Levine et al., 1999), We have added this relevant literature in the revised version.

8. In pre-monsoon season, forest-edge comprised of high species richness, followed by fallow land and roadside, however in the monsoon season, the fallow land comprised of highest number of species followed by forest-edge and roadside respectively. What are the possible reasons? Support your results logically with the help of available literature.

Response 8: We have added the following points in the revised version of manuscript. The observed seasonal changes in species richness across different habitats—forest-edge, fallow land, and roadside—can be attributed to various ecological and environmental factors such as microclimate (Harper et al., 2005), emergence of opportunistic species (Guo et al., 1996), water availability (Baskin and Baskin., 2014)

 

9. The soil nutrients were higher in invaded sites compared to non-invaded sites except available Potassium and soil pH in both pre-monsoon and monsoon season. What are the possible reasons? Support your results logically with the help of available literature.

Response 9: The higher amount of soil nutrients in invaded sites were found both in pre-monsoon and monsoon season, this might be due to higher capability of nutrient use efficiency of Lantana camara and their high rate of litter decomposition in comparison to other species [28].

 

10. In total, the soil nutrients like soil organic carbon, total nitrogen and available phosphorus of invaded sites increased by 11.61%, 28% and 24.03% respectively. Regarding the habitat type total nitrogen, available phosphorus, available potassium and soil pH were higher in fallow land followed by forest-edge and roadside while the total soil organic carbon was highest in forest-edge and lowest in roadside. What are the possible reasons? Support your results logically with the help of available literature.

Response 10: The related information is described in the discussion section with relevant literature Lines 269-283 in the revised section.

 

Conclusion

 

1. Please rewrite conclusion which includes highlights of your results.

Response 1: We have revised the conclusion in the revised version.

 

2. What you recommend for future?

Response 2: We have mentioned that studies on comparative physiological traits of invasive and native species and soil microbial dynamics would help refine our knowledge on plant invasion.

3. What are the benefits of this study?

Response 3: We have added that the findings are highly important to forest/biodiversity managers and farmers.

 

Reviewer 2 Report

Comments and Suggestions for Authors

Review of the article „High impacts of invasive weed Lantana camara on plant community and soil physio-chemical properties across habitat types in central Nepal”

I appreciate the choice of a valuable research topic and support all publications on invasions. The proposed article is relatively well-written. However, it requires a major revision, and below are my suggestions for improvement.

The most important objection: the authors over interpret the results. The conducted studies are correlational, not experimental, so it is not justified to use causative relationships in the interpretation. Lower plant species diversity in invaded sites compared to uninvaded sites does not mean that the cause is invasive plants, nor that the invasion reduced species diversity. It may also result from reduced space available for native plants during invasion or their increased density. These are phenomena that can occur regardless of the studied invasion. Therefore, I suggest greater caution in interpreting the results.

Introduction. I suggest writing more specific hypotheses at the end of the chapter, and in particular, proposing the direction of the studied invasion impact – was its expected effect on diversity predicted as negative or neutral?

Chapter 2.2. The authors do not explain the reasons for choosing the size of the study areas. I suggest explaining whether they had previous experience with the described habitats and knew what areas could be sufficient to describe species diversity. On what basis did they conclude that the selected areas would be enough to detect the impact of the studied invasive plant? Did they know, for example, the range of chemical or visual effects of the invasion on the surrounding diversity?

Chapter 2.3. The authors chose parametric statistical methods, but it is not known whether the dependent variables were normally distributed and what were the results of the test investigating the homogeneity of the invasion.

Results. The tables are unreadable and should be corrected.

The article's hypotheses do not state that the season when the data was collected may be important for the impact of the invasion, meanwhile, this is a large part of the analysis in the results. The hypotheses should be supplemented.

There is no description of the habitat categories, i.e., fallow land, forest edge and roadside. Was the distinction always easy? How did these categories differ and what was the point of separating them? This is important because the authors discuss the differences between these habitats.

In summary, the authors have collected valuable material, but they should work on the hypotheses, the coherence of the article and the interpretation, and organize it better.

Comments on the Quality of English Language

Please, check English language carefully. 

Author Response

2^nd Review

Review of the article „High impacts of invasive weed Lantana camara on plant community and soil physio-chemical properties across habitat types in central Nepal”

 

I appreciate the choice of a valuable research topic and support all publications on invasions. The proposed article is relatively well-written. However, it requires a major revision, and below are my suggestions for improvement.

Response: We thank Reviewer 2 for very constructive and critical comments. We have incorporated these issues in the revised version.

 

The most important objection: the authors over interpret the results. The conducted studies are correlational, not experimental, so it is not justified to use causative relationships in the interpretation. Lower plant species diversity in invaded sites compared to uninvaded sites does not mean that the cause is invasive plants, nor that the invasion reduced species diversity. It may also result from reduced space available for native plants during invasion or their increased density. These are phenomena that can occur regardless of the studied invasion. Therefore, I suggest greater caution in interpreting the results.

Response: We have realized the overinterpretation at some points. Hence, we have revised the line of results as L. camara poses a substantial impact to species richness, community assemblage and species diversity, as well as the soil properties. Lines 352-354 in the revised manuscript

 

Introduction. I suggest writing more specific hypotheses at the end of the chapter, and in particular, proposing the direction of the studied invasion impact – was its expected effect on diversity predicted as negative or neutral?

Response: We made it simple in revised version Line 91-94.

Chapter 2.2. The authors do not explain the reasons for choosing the size of the study areas. I suggest explaining whether they had previous experience with the described habitats and knew what areas could be sufficient to describe species diversity. On what basis did they conclude that the selected areas would be enough to detect the impact of the studied invasive plant? Did they know, for example, the range of chemical or visual effects of the invasion on the surrounding diversity?

Response:  We chose these habitat types as they appeared to be highly invaded sites by L. camara while conducting a reconnaissance survey prior to this study. Central Nepal with ca 200-1500 m altitude zone is one of the highly invaded areas by L. camara, and the habitats we chose forest-edge, fallow-land and roadsides are more common habitats for L. camara invasion as evidenced by reconnaissance survey.

 

 

Chapter 2.3. The authors chose parametric statistical methods, but it is not known whether the dependent variables were normally distributed and what were the results of the test investigating the homogeneity of the invasion.

Response: Yes, we did parametric tests as the variance were generally normal (P > 0.05). P values can be checked from Tables in Appendix B.

Results. The tables are unreadable and should be corrected.

Response: Thank you. The data presented in table was same as given in figures, hence we removed tables from the text body and kept in Appendix B

 

The article's hypotheses do not state that the season when the data was collected may be important for the impact of the invasion, meanwhile, this is a large part of the analysis in the results. The hypotheses should be supplemented.

Response: We have added a brief about climate patterns, monsoon seasonality and their potential role in plant invasion in the Introduction section with relevant references. Lines 64-67. And mentioned seasonality in the study area Line 103-106 in revised manuscript.

 

There is no description of the habitat categories, i.e., fallow land, forest edge and roadside. Was the distinction always easy? How did these categories differ and what was the point of separating them? This is important because the authors discuss the differences between these habitats.

Response: Thank you for this comment, we introduced these three habitat types in Materials and Methods section Lines 119-124 in the revised manuscript.

 

In summary, the authors have collected valuable material, but they should work on the hypotheses, the coherence of the article and the interpretation, and organize it better.

Response: Thank you, we revised and improved the manuscript accordingly.

Author Response File: Author Response.doc

Reviewer 3 Report

Comments and Suggestions for Authors

Sec. 3.1.

We found 137 species of flowering plants from 49 families, of which 40 were recorded only in non-invaded sites and 18 only in L. camara invaded sites (Appendix 1). Additionally, 79 plant species were present in both non-invaded and invaded sites.


Or: We found 137 species of flowering plants from 49 families, of which 119 were recorded in non-invaded sites and 97 in L. camara invaded sites (Appendix 1). However, it should be taken into account that 79 plant species were present in both non-invaded and invaded sites.

Comments for author File: Comments.pdf

Comments on the Quality of English Language

Author Response

Reviewer 3

Comment: We found 137 species of flowering plants from 49 families, of which 40 were recorded only in non-invaded sites and 18 only in L. camara invaded sites (Appendix 1). Additionally, 79 plant species were present in both non-invaded and invaded sites.

Or: We found 137 species of flowering plants from 49 families, of which 119 were recorded in non-invaded sites and 97 in L. camara invaded sites (Appendix 1). However, it should be taken into account that 79 plant species were present in both non-invaded and invaded sites.

Response: Yes, we found 137 species of flowering plants from 49 families, of which 119 were recorded in non-invaded sites and 97 in L. camara invaded sites (Appendix A). Additionally, 79 plant species were present in both non-invaded and invaded sites. (Lines 168-170 in revised manuscript)

Reviewer 4 Report

Comments and Suggestions for Authors

The article is well written and interesting.

Author Response

Comment: The article is well written and interesting.

Response: Thank you