Spatial Distribution Patterns of the Key Afforestation Species Cupressus funebris: Insights from an Ensemble Model under Climate Change Scenarios
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThe manuscript provides insight to the potential distribution of Cupressus funebris in the context of climate change. In general, I have a positive impression from this study. However, there are some questions and suggestions intended to improve the discussion of the obtained results. Some minor shortcomings have been revealed too.
Section 2.1. Collection of sample and species distribution records
The most uncertainty concerns natural and artificial habitats of Cupressus funebris. Authors mentioned that this species is listed as endangered protected plant (line 87), and occupies important position in afforestation position (line 93). I guess some of distribution points are from plantations or even botanical gardens, etc. However, there is no information on assessment of natural/artificial status of habitats when occurrence records were collected. In my point of view, in order to analyze the niche changes the difference between artificial and natural habitats should be taken into account. The reason is that it is not the same when the species is planted in some areas chosen by humans, and from the other hand when it is self-established in suitable habitats.
Line 120:
Begin in capital – “We verified …”
Lines 123-124:
Probably you mean: … only one distribution point was selected from each of the 123 grids with a size of 5 km x 5 km.
Line 149:
Probably missed “The ensemble model allows …”
Section 2.4. Niche changes
It is not correct to say that the niche will change. The niche will be the same, but geographical distribution of convenient environmental conditions will change. As a result, change of areas coinciding with the niche parameters will occur.
The same shortcomings appeared in the Section 3.4. Future ecological niche changes analysis, and partly in Figure 5 caption.
Also, the Discussion section should be carefully checked to avoid this incorrect expression.
Section 2.5. Analysis of stand characteristics
It looks like the choice of the habitats’ suitability was subjective. Authors decided choose first, then assess differences between habitats. But what was the criteria to decide that this habitat was highly suitable, moderately (medium) suitable, low suitable? I guess, in case there are no well pronounced criteria, authors should, conversely, make the choice on the base of the assessment of habitats.
Line 214:
Delete the dot after “Figure”
Line 213.
I suggest to describe the niche characteristics before the 3.2. Current potential geographical distributions of C. funebris. Without such description the niche remains “a black box”.
Lines 233-234 and 329-331:
Projected decreasing low suitable areas looks as a doubtful artefact and I suggest to discuss it as well.
Lines 295, 298:
I guess “minimally suitable area” is the same as “low suitable area”. So, the same epithet “low” is preferable as used in the text above.
Line 368:
Replace “Water” for “Humidity”.
Line 377:
Probably, it is better to say “consumed” instead of “occupied”.
Author Response
Comments 1: Section 2.1. Collection of sample and species distribution records
The most uncertainty concerns natural and artificial habitats of Cupressus funebris. Authors mentioned that this species is listed as endangered protected plant (line 87), and occupies important position in afforestation position (line 93). I guess some of distribution points are from plantations or even botanical gardens, etc. However, there is no information on assessment of natural/artificial status of habitats when occurrence records were collected. In my point of view, in order to analyze the niche changes the difference between artificial and natural habitats should be taken into account. The reason is that it is not the same when the species is planted in some areas chosen by humans, and from the other hand when it is self-established in suitable habitats.
Response 1: The collection of Cupressus funebris distribution records in this study was based on field surveys conducted by the Innovation Team for Quality Improvement of Artificial Forests of Cupressus funebris at Mianyang Normal University from 2019 to 2024, as well as queries from the Chinese Virtual Herbarium database. To ensure data accuracy, any misidentified sample points were verified and removed. Although some distribution points come from artificial forests and thus artificial habitats, from the perspective of plant ecological adaptation, the fact that these Cupressus funebris can grow into forests indicates that these habitats are suitable for the species. Therefore, the collected distribution points are considered valid. Additionally, to avoid model overfitting due to overly concentrated distribution points, only one distribution point per grid (5 km × 5 km) was retained, resulting in a total of 368 valid distribution points.
Comments 2: Line 120: Begin in capital – “We verified …”
Response 2: We have modified to: “This study verified.”
Comments 3: Lines 123-124:
Probably you mean: … only one distribution point was selected from each of the 123 grids with a size of 5 km x 5 km.
Response 3: Thank you for your comments. We have revised it to: “To prevent model overfitting due to the excessive clustering of distribution points, only one distribution point was selected from each of the 123 grids with a size of 5 km x 5 km. Ultimately, 368 valid occurrence records were obtained, as shown in Figure 2.”
Comments 4: Line 149:
Probably missed “The ensemble model allows …”
Response 4: The phrase “The ensemble model allows”has been added. See line 164
Comments 5: Section 2.4. Niche changes
It is not correct to say that the niche will change. The niche will be the same, but geographical distribution of convenient environmental conditions will change. As a result, change of areas coinciding with the niche parameters will occur.
The same shortcomings appeared in the Section 3.4. Future ecological niche changes analysis, and partly in Figure 5 caption.
Also, the Discussion section should be carefully checked to avoid this incorrect expression.
Response 5: Niche changes have been revised to niche shifts. See lines 37, 109, 192, 294.
Comments 6: Section 2.5. Analysis of stand characteristics
It looks like the choice of the habitats’ suitability was subjective. Authors decided choose first, then assess differences between habitats. But what was the criteria to decide that this habitat was highly suitable, moderately (medium) suitable, low suitable? I guess, in case there are no well pronounced criteria, authors should, conversely, make the choice on the base of the assessment of habitats.
Response 6: In this study, a 0/1 threshold (cut off) was obtained from the model output. Areas below the threshold are considered unsuitable, while areas above the threshold are divided into three equal parts, corresponding to low, medium, and high suitability regions (cut off=0.476). Finally, the classification results were loaded into ArcGIS v10.4.1 for visualization. In this study, five plots were set up in the high suitability area for C. funebris, five plots in the medium suitability area, and five plots in the low suitability area to investigate stand characteristics. The reasons for setting up C. funebris plots in the Zitong forest area of Mianyang are: (1) The Zitong forest area of Mianyang has all three suitability areas for C. funebris, meeting the research needs; (2) The Zitong forest area of Mianyang is the closest area to the team's base that meets the research requirements; (3) Our team already has several fixed plots in the Zitong forest area of Mianyang.
Comments 7: Line 214:
Delete the dot after “Figure”
Response 7: We have made modifications.
Line 213.
Comments 8: I suggest to describe the niche characteristics before the 3.2. Current potential geographical distributions of C. funebris. Without such description the niche remains “a black box”.
Response 8: The description of the niche characteristics of C. funebris has been added. See lines 238-244
Comments 9: Lines 233-234 and 329-331:
Projected decreasing low suitable areas looks as a doubtful artefact and I suggest to discuss it as well.
Response 9: The ensemble model prediction shows that the potential distribution of C. funebris will generally increase under various climate scenarios, except for a slight decrease in the low suitability area under the 2050s-SSP126 scenario. This is due to the niche shifts of C. funebris caused by climate change. Although climate change is generally beneficial for C. funebris, it can easily cause the ecological environment of low suitability areas to exceed their thresholds, rendering them unsuitable. I have added this related discussion in the discussion section. See lines 382-397
Comments 10: Lines 295, 298:
I guess “minimally suitable area” is the same as “low suitable area”. So, the same epithet “low” is preferable as used in the text above.
Response 10: We have made modifications. See lines 331, 334
Comments 11: .Line 368:
Replace “Water” for “Humidity”.
Response 11: We have replaced it in the article. See lines 454-455.
Comments 12: Line 377:
Probably, it is better to say “consumed” instead of “occupied”.
Response 12: We have replaced it in the article. See line 465.
In conclusion, we have tried our best to improve the manuscript and have made comprehensive changes in this paper. After reading the latest version of our manuscript, we hope you will have a better understanding of this manuscript and look forward to your evaluation. We earnestly appreciate the reviewers’ work and we hope that the changes and corrections will meet with your approval. Once again, thank you very much for your comments and suggestions.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsComments for author File: Comments.pdf
Author Response
Comments 1: Please avoid using pronouns such as “we”, “our”, and “us” in the entire text (e.g., line 102).
Response 1: Thanks to the opinions of reviewer, we have carefully revised the manuscript.
Comments 2: Please replace keywords that are already mentioned in the title (e.g., Cupressus funebris and climate change) with other terms.
Response 2: we have replaced. see line 37.
Introduction:
Comments 3: Page 2, line 51: Consider revising this statement “These shifts may have far-reaching consequences for their future productivity and the ecosystem as a whole” for more clarity and readability”.
Response 3: we have revised the sentence for improved clarity and accuracy. The revised sentence is as follows:
“These changes may significantly impact their future productivity and the overall health of the ecosystem.” see lines 52-53.
Comments 4: Page 3, lines 102-104: This statement “In this study, we employed the Biomod2 platform to simulate the alterations in the spatial distribution patterns of C. funebris under current and future climate conditions, utilizing both its distribution data and environmental data.” should be revised.
Response 4: we have revised the sentence for improved clarity and accuracy. The revised sentence is as follows:
“In this study, China's heterogeneous geographical and climatic environments were used as a natural testing ground. For the first time, the biomod2 ensemble model was used in combination with the team's field survey data to simulate the potential geographic distribution of the important afforestation species C funebris under modern climate conditions and to predict its potential geographic distribution under future climate change scenarios. This study also explored the niche shifts of Cupressus funebris under future climate change scenarios and the stand characteristics of Cupressus funebris in different habitat suitability levels.” see lines 104-111
Comments 5: Explain the novelty of the study, you should explain what makes this study different from other studies. So, you need a strong literature review.
Response5: A reference to a Nature Communications article was added when introducing the biomod2 model, and the novelty of the paper as well as its differences from other papers were introduced at the end of the introduction. see lines 75, 104-111, 116-118
Material and methods:
Comments 6: In this section, a new sub-section (i.e., Study area) will be considered, and the area where this research was done should be introduced.
Response 6: Thank you for your suggestion. The study area overview has been added, as follows:
“This study covers the entire country of China. Located in East Asia on the western edge of the Pacific Ocean, China has a vast territory that spans multiple latitudes and varies greatly in distance from the sea. The diverse topography, including varying elevations and mountain orientations, results in a wide array of climate types and complex temperature and precipitation patterns.In terms of climate, eastern China experiences monsoon climates, which include subtropical, temperate, and tropical monsoon climates. Northwestern China has a temperate continental climate, while the Qinghai-Tibet Plateau features a high-altitude climate. The temperature zones range from tropical and subtropical to warm temperate, temperate, cold temperate, and the unique Qinghai-Tibet Plateau zone.China also boasts a rich diversity of soil types, making its soil resources suitable for various agricultural, forestry, and pastoral activities. Mountainous regions, in particular, have abundant soil resources that support the growth of economic forest trees” see lines 123-136,
Comments 7: In line 160, remove the term “Random Forest” before its abbreviation since it has already been introduced.
Response 7: We have removed. see line 182.
Results and discussions:
Comments 8: In this section, you should explain how the expected changes in distribution and location changes will affect the species and its ecosystem.
Response 8: The expected changes in distribution and location and their impact on the species and its ecosystem have been explained in this section, see lines 361-371, 397-402.
Comments 9: Please make sure that all tables and figures are cited in the main text correctly.
Response 9: It has been verified.
Comments 10: Figure 6 should be replaced with another figure with better resolution.
Response 10: Figure 6 has been replaced with a higher resolution version.
Discussion:
Comments 11: In the Discussion, state the study's main results and do not repeat the findings of the results section.
Response 11: In the discussion, the main results of the study have been stated, and some findings of the results have been removed. See lines 382-389.
Comments 12: In addition, compare and interpret the results in detail with the findings of recent studies.
Response 12: The results have been compared and explained in detail with recent studies. See lines 417-431.
Comments 13: The main limitations of the study should be added to this section.
Response 13: The limitations of the study have been added. See lines 483-498. as follows:
“This study predicts the potential geographic distribution of C. funebris in China. The results of this study represent the first step in macro-level planning and are crucial for the scientific management and provision of suitable habitats for the species' survival and reproduction. The expansion or reduction of the study area may change the range of environmental factors that limit growth. Other environmental factors, such as vegetation cover, also have a certain impact on the potential geographic distribution of plants [64]. Since it is impossible to accurately predict the future vegetation cover in China, it was not included in the geographic distribution prediction. Therefore, some areas within the potential geographic distribution obtained in this study may not be suitable for survival. The study only used 37 environmental factor variables for the two time periods of 2050 and 2090. Therefore, in future research on the response of species' potential geographic distributions to climate change, it is advisable to select multiple study periods, incorporate more environmental factor variables, and choose appropriate study area ranges based on practical needs. This will help to determine the overall trend of changes in the potential geographic distribution of the research subject.”
Conclusion:
Comments 14: This section should focus on the main results and demonstrate how thoroughly the research objectives have been addressed.
Response 14: The conclusion section has been rewritten. as follows:
“This study uses the heterogeneous geographic and climatic environment of our country as a natural testing ground. It employs the biomod2 ensemble model to simulate the potential geographic distribution of an important afforestation tree species, C. funebris, under current climatic conditions, and predicts the potential geographic distribution under future climate change scenarios. The study explores the niche changes of C. funebris and the stand characteristics of C. funebris under different habitat suitability in future climate change scenarios. The results show that under current climatic conditions, the highly suitable areas for C. funebris are mainly concentrated in southern provinces and cities such as Sichuan, Chongqing, and Guizhou. Under different future climate scenarios, except for a 3.45% reduction in the low suitability area of C. funebris under the 2050 SSP126 scenario, the potential distribution areas under other climate scenarios have increased compared to the current period, showing a trend of expansion towards the northeast. The expansion areas are concentrated in mid-high latitude provinces such as Henan, Shandong, and Hebei, and the climatic niche will correspondingly migrate gradually.
This study clarifies the changes and heterogeneity of C. funebris in different regions of our country in future periods. The study indicates that C. funebris has a strong ability to adapt to future climate change, providing a theoretical basis and technological support for the protection, afforestation, and industrial development of C. funebris. In the future, it is necessary to select appropriate research areas based on production practice needs, consider more research periods, and include more environmental factor variables to study the overall trend of the potential geographic distribution of the research object.”
Comments 15: The theoretical and practical implications of the study should be added to this section.
Response 15: The conclusion section has been rewritten. See response 14
Comments 16: It is essential to improve this section by adding paragraphs that discuss the international policy implications of the study's findings.
Response 16: The conclusion section has been rewritten. See response 14
Comments 17: The direction of future studies should be mentioned at the end of the Conclusion section
Response 17: The conclusion section has been rewritten. See response 14
In conclusion, we have tried our best to improve the manuscript and have made comprehensive changes in this paper. After reading the latest version of our manuscript, we hope you will have a better understanding of this manuscript and look forward to your evaluation. We earnestly appreciate the your work and we hope that the changes and corrections will meet with your approval. Once again, thank you very much for your comments and suggestions.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
Comments and Suggestions for AuthorsReviewer comments to the Revised manuscript
“Spatial Distribution Patterns of the Key Afforestation Species Cupressus funebris: Insights from an Ensemble Model under Climate Change Scenarios”
I can see that authors corrected the manuscript according to many comments. However, there is still sufficient misunderstanding of comments related to the species distribution records, “Niche” itself, and “Niche changes”.
First of all, I don’t agree that (Response 1): “Although some distribution points come from artificial forests and thus artificial habitats, from the perspective of plant ecological adaptation, the fact that these Cupressus funebris can grow into forests indicates that these habitats are suitable for the species. Therefore, the collected distribution points are considered valid”. The reason lies in difference between conditions for seed germination and seedlings survival from the one side, and conditions suitable for adult trees grows. Typically, seed germination and seedlings survival require more favorable conditions than its are satisfactory for adult trees grows. Until you have no evidences to refute this pattern, you cannot say that artificial forest grown from saplings covers all the range of habitats suitable for Cupressus funebris. Consequently, your findings in the manuscript are related to modelling geographical span of conditions more or less suitable for the opportunity to plant C. funebris, but not to modelling geographical span of the C. funebris niche under projected climate changes.
Secondly, it is not correct to substitute “Niche changes” for “Niche shifts” (Response 5). I guess this basic methodological mistake is originated from the wrong understanding what is the “Niche” itself. To the “Niche” itself the rigid combination of environmental parameters is inherent, so the “Niche” is not changes or shifts. But geographical distribution of convenient environmental conditions can change. Accordingly, the Niche geographical coverage will change, but not the Niche itself.
From my point of view, both comments above show that the authors need to understand more deeply what findings they received as a result of this study. In the present form the manuscript looks like not enough polished in the methodological sense.
Author Response
Comment 1: First of all, I don’t agree that (Response 1): “Although some distribution points come from artificial forests and thus artificial habitats, from the perspective of plant ecological adaptation, the fact that these Cupressus funebris can grow into forests indicates that these habitats are suitable for the species. Therefore, the collected distribution points were considered valid”. The reason lies in difference between conditions for seed germination and seedlings survival from the one side, and conditions suitable for adult trees grows. Typically, seed germination and seedlings survival require more favorable conditions than its are satisfactory for adult trees grows. Until you have no evidences to refute this pattern, you cannot say that artificial forest grown from saplings covers all the range of habitats suitable for Cupressus funebris. Consequently, your findings in the manuscript are related to modeling geographical span of conditions more or less suitable for the opportunity to plant C. funebris, but not to modeling geographical span of the C. funebris niche under projected climate changes.
Response 1: Thank you for this comment. After careful consideration, our research group believes that this is absolutely correct. In most cases, the environmental conditions required for seed germination are more demanding than those required for the growth of adult trees. Therefore, the model based on distribution records from artificial habitats may have some impact on the prediction results.The reason our research group selected the distribution records of Cupressus funebris from artificial habitats in the model predictions is that this study is a macro-scale planning effort. We aimed to provide a theoretical basis for the ex-situ conservation and rational utilization of Cupressus funebris. Including distribution records from artificial habitats increases the likelihood of identifying more potential habitats for Cupressus funebris.
Additionally, by predicting the potential distribution of the energy tree species Triadica sebifera [1] (a species already widely planted) using niche models, and similarly predicting the potential distribution of the cultivated species Triticum spp. [2], Manihot esculenta [3], Brassica napus [3], Oryza sativa [4], and Zea mays [5] further illustrate that incorporating some distribution records of Cupressus funebris from artificial habitats into the potential distribution prediction is necessary for ex-situ conservation and rational utilization of Cupressus funebris.
Thank you for your suggestion. In future research, we will separately predict the distribution of Cupressus funebris in its natural habitats. We also acknowledge this limitation and include it in our research outlook (Lines 501-504). Specifically, the following:
In this study, distribution records of Cupressus funebris were obtained from both artificial and natural habitats. Distribution records from artificial habitats may have some impact on the prediction results of the niche model. Therefore, future research should consider the effects of artificial habitat distribution records on the prediction results.
[1] Mei Liu, LiyongYang, Miaomiao Su, WeiGong, Yibo Liu, JingxuanYang, Yi Huang*, Cong Zhao*. Modeling the potential distribution of the energy tree species Triadica sebifera in response to climate change in China. scientific reports. 2024. 14.1124.
[2] Bo C, Cb C, Meng Z B, et al. Future landscape of renewable fuel resources: Current and future conservation and utilization of main biofuel crops in China[J]. The Science of the Total Environment, 2022, 806(Oct.04): 0048-9697.
[3] Yue Y, Zhang P, Shang Y. The potential global distribution and dynamics of wheat under multiple climate change scenarios[J]. The Science of the Total Environment, 2019, 688(Oct.20):1308-1318.
[4] Xing Y, Xu T, Jun L, et al. Predicting potential cultivation region and paddy area for ratoon rice production in China using Maxent model[J]. Science of the Total Environment, 2022, 275, 0378-4920.
[5] Santana P A, Kumar L, Da S, et al. Assessing the impact of climate change on the worldwide distribution of Dalbulus maidis (DeLong) using MaxEnt[J]. Pest. Manag. Sci, 2019, 75: 2706-2715.
Comment 2: Secondly, it is not correct to substitute “Niche changes” for “Niche shifts” (Response 5). I guess this basic methodological mistake is originated from the wrong understanding what is the “Niche” itself. To the “Niche” itself the rigid combination of environmental parameters is inherent, so the “Niche” is not changes or shifts. But geographical distribution of convenient environmental conditions can change. Accordingly, the Niche geographical coverage will change, but not the Niche itself.
From my point of view, both comments above show that the authors need to understand more deeply what findings they received as a result of this study. In the present form the manuscript looks like not enough polished in the methodological sense.
Response 2: Thank you for your suggestion. We also believe that the niches do not shift or change. Our previous statement was incorrect. We agree that describing it as a change in the geographical range of a niche is more accurate. We have made this correction in the text, consistently using "change in the geographical range of the niche."。
Once again, we sincerely appreciate your professional and constructive comments. Thank you for your time and effort in reviewing our manuscript.
Kind regards,
Jingtian Yang
Reviewer 2 Report
Comments and Suggestions for AuthorsThe authors addressed the comments in previous revision carefully. However, there are still some issues that need consideration.
Comments for author File: Comments.pdf
Author Response
Comment 1: English grammar and style should be checked throughout the manuscript.
Response 1: We corrected these grammatical mistakes and styles with the help of a special English researcher. Zhaocong (Southwest Jiaotong University). He had studied abroad and was proficient in English.
Comment 2: Given that the study presents a long list of abbreviations, I suggest adding a “glossary” table at the end of the paper as it will aid the readers in learning about the concepts/terms that they are about to study.
Response 2: We have added a glossary table at the end of the manuscript.
Comment 3: The first letter of the keywords should be capsized.
Response 3: We have corrected the first letter of the keywords.
Comment 4: Lines 40-42 on page 1: These sentences should be supported by relevant references.
Response 4: We have added one relevant reference to support these sentences in Lines 40-42 on page 1.
Comment 5: The authors should highlight the specific and practical suggestions with respect to their findings at the end of the conclusion section in one paragraph.
Response 5: We have emphasized the specific and practical suggestions based on our findings in the Conclusion section.
