Climate-Driven Range Shifts of the Endangered Cercidiphyllum japonicum in China: A MaxEnt Modeling Approach

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The manuscript is dealing with the assessment of distribution range and the species range shift under varying climate change scenario for an endangered species Cercidiphyllum japonicum in China, using MaxEnt modeling. Climate change is considered as a major cause of range shift and loss of a range of biodiversity in different regions of the world. Endemic, rare and endangered species are highly vulnerable and are at greater risk to the climate change mediated loss cum extinction. With this scenario, assessment of various species distribution and their population status holds crucial importance. So the work is contemporary. There are a number of studies have been done to assess the distribution range of a particular species and their future distribution pattern under different climate change scenarios using MaxEnt models. SO this work is a part of such global research agenda. The present work is limited to assessing the distribution of the selected species under different climate change scenarios in China. Authors have considered three SSP scenarios and observed the present, 2050s and 2090s distribution scenario of the species distribution. A few related works have been done on the species distribution, however, the manuscript has merit to be considered for publication. The content of the manuscript is interesting and presented well. However, for more detailed insight, the manuscript needs to be thoroughly revised in light of the suggestions given in the attached pdf file.

Particularly, the Abstract can be better presented by providing a detailed insight on the distribution of species and the implications of the findings of the study. Introduction section needs to be updated in light of recent literature support, mention a few studies related to the distribution of the species, and what is the novelty of this work if the studies on distribution of the plant species are already available, it should be clearly mentioned it before posing the objectives of the study. In addition, also throw some light on why only China, why not global perspective on the species distribution was considered. What is the present scenario of the availability of this species? Is it endemic to China or present globally. What are the threats to this species and what conservation measures are being taken into account at present? All these information should be part of the Introduction section. Some sections in the methodology can be elaborated (mentioned in pdf file). The results section is too elaborate and authors are advised to highlight and present key findings only which have been discussed in detailed in the discussion section. No need to present all the results which are already given in the Tables and Figures. Similarly, key findings can be elaborated in the discussion section in light of recent literature. The caption of Figures an Tables can be elaborated and better presented. There are a number of typos and word sticking problem throughout the manuscript, some of the sentences are not clearly presented and also seem incomplete. Authors need to work on this as well. The conclusion section can also be improved by presenting the key highlights and implications of the study. See the attached pdf file for detailed and specific comments.

Comments for author File: Comments.pdf

Comments on the Quality of English Language

There is a major issue of word sticking, incompleteness of sentences and a few sentences are not clearly presented. Authors also advised to cross check the units of some of the data presented. Rephrase the unclear sentences and captions of the figures and tables for more clarity. Some of the unclear/incomplete sentences are marked in the attached pdf file.

Author Response

Please see the attachment

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The paper is relevant to the current situation of fast climate change. The nationally protected relic tree species, Cercidiphyllum japonicum, is appropriately chosen as a research object. The MaxEnt modelling approach, being increasingly used by researchers, is well suited for the prediction of species’ future distribution and can provide as precise results as more environmental variables are employed. And it looks like the authors fulfilled the latter condition. Although the paper is well written, some amendments and corrections are necessary. Please find my suggestions and comments below.

Lines 97–98: Replace “Global Biodiversity Information Service” with “Global Biodiversity Information Facility”.

Line 124: Explain, please, what is meant under “Human variables”.

Line 130: Regarding “the contribution rate of variables to the model” could you provide some more details?

Line 133: I suggest replacing “together with topographic factors, soil factors, chemical factors and human factors” with “together with elevation factor, soil factors, solar radiation factor and human factor” as only elevation of the topographic factors was used as well as only solar radiation in a form of UVB was used.

Line 145: It is essential to provide major features of the “three scenarios of SSP1-2.6, SSP2-4.5 and SSP5-8.5” (is it based only on different greenhouse gas concentration scenarios?) and to explain how these scenarios relate to the scenarios RCP2.6, RCP4.5 and RCP8.5, because the latter are presented in Table 5, while in Abstract only the former ones are mentioned.

Table 1: In the caption, provide citation of where from (or explanation of how) the “Percent contribution” and “Permutation importance” were obtained. Are these calculated for a given species particularly? Replace “Mean Diurnal Range” with “Temperature Mean Diurnal Range”.

Table 2: The content needs some arrangement. I suggest replacing forward slash with N/A or leaving just a blank cell in the column ‘Unit’. “Soil reference depth” usually has a unit ‘m’ (meter). The ultraviolet-B radiation is a physical variable, or solar radiation variable, but not chemical. The unit of Isothermality should be % instead of ×100. The numbers of lines 170–173 should be right-aligned.

Line 199: Explain, please, what does an IPCC stand for.

Line 239: The subsection entitled “3.3. The current distribution of C. japonicum in China was simulated based on MaxEnt” (it resembles a narrative rather than a title) should start with a text and then be followed by an illustration and/or table. The same layout corrections needed in the subsections 3.4, 3.5 and 3.6.

Lines 242–243: The text in brackets is redundant because all that information is already given in the map legend above.

Lines 250–252: “The total suitable area (including high suitable area, medium suitable area and low suitable area) is 95071 km², accounting for 0.989 % of the total area of the whole country (Table 4).” However, the heading of the last column in Table 4 reads “Percentage of high suitable areas in China (%)”. Please correct it to match the text. Also, explain how the percentages were calculated in the last column of Table 4.

Table 7: The centroid displacement trajectory of C. japonicum suitable habitats under the first scenario (SSP1-2.6) takes opposite directions if compared time periods “Contemporary to 2050s” and “2050s to 2090s”. How would you explain this?

Lines 475–477: The preciseness of temperature (-12.225℃~3.132℃) and precipitation (611.111mm ~ 1732.320mm) is too high in the context of this type of study. This would be appropriate in laboratory research, but not in field conditions.

Comments for author File: Comments.pdf

Author Response

Please see the attachment

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The manuscript has been revised substantially in light of the suggestions given earlier. There are a few typological errors which can be curated during the time of proofreading. In addition, scientific names of the plants in the discussion section are not presented in italic. Please present the same in italic before proceeding further, or curate at the time of proofreading stage. Please also check if the similarity index of the manuscript is below the accepted limit before proceeding further.

Author Response

Please see the attachment

Author Response File: Author Response.docx