Quantifying Spatiotemporal Characteristics and Identifying Influential Factors of Ecosystem Fragmentation in Karst Landscapes: A Comprehensive Analytical Framework

Round 1

Reviewer 1 Report

Taking Guanling-Zhenfeng County as the study area, the article proposed a comprehensive framework of "quantification of spatiotemporal characteristics of landscape fragmentation - identification of dominant factors - analysis of spatial differentiation - prediction of future scenarios" by combining multiscale geo-weighted regression (MGWR) and the PLUS model, and quantitatively explored the changes in spatial and temporal patterns of landscape fragmentation and its driving factors in the region. The research objectives are clear, the research method is appropriate and full of logical ideas. On the whole, there are still the following deficiencies, and the feedback on the revision is as follows:

1.     Introduction: (1) The introduction of the background of the study is a bit empty and does not provide enough background information；(2) Lack of specificity and comprehensiveness in the description of research progress, as well as failure to summarize the limitations of current relevant research; (3) Failure to highlight the importance and specificity of the chosen topic; (4) The value of the research, the innovation is not obvious.

2.     Study area: Content does not reflect the research significance of the study area.

3.     Results: (1) Simply doing a literal translation of the charts and graphs suggests a brief explanation of the reasons behind them; (2) Inconsistency in the location of the various vignettes in Figure 2; (3) Inconsistent positions of (a), (b) and (c) in Figure 3; (4) In Figure 5, (h) is not in the same position as the other figures, and the font size of the legends (c)-(h) is not consistent.

4.     Discussion: (1) Lack of in-depth discussion related to the topic; (2) The mechanism behind failed to dig deeper.

5.   Conclusion: The main findings should be summarized accurately, concisely and completely, highlighting the research contribution.

Comments for author File: Comments.pdf

Overall, ok. However, some English grammar in the text still needs revision.

Author Response

Dear  Reviewer,

Thanks for your comments concerning our manuscript entitled “Quantification of spatiotemporal characteristics and identification of drivers of landscape fragmentation in karst ecosystems: An integrated analytical framework” (Manuscript ID:land-2844346). Those comments are all valuable and very helpful for revising and improving our paper. We have studied the comments very carefully and made our best efforts to enhance our paper. Our point-by- point response to the comments made by Reviewer is given below. We have also marked changes in the manuscript with green. We hope the revised manuscript will be accepted by the Reviewer. If still there are concerns, we will be happy to take care of once.

Author Response File: Author Response.docx

Reviewer 2 Report

In the paper “Quantification of spatiotemporal characteristics and identification of drivers of landscape fragmentation in karst ecosystems: An integrated analytical framework” the authors integrates multiscale geo-weighted regression (MGWR) and the PLUS model to propose a comprehensive framework of "quantification of spatiotemporal characteristics of landscape fragmentation - identification of dominant factors - analysis of spatial differentiation - prediction of future scenarios" to quantitatively explore the spatiotemporal pattern changes and driving factors of regional landscape fragmentation. This manuscript is well organized, and the drawn conclusions are coherent with the obtained results. I have enjoyed reading your paper; however, the manuscript must be revised by an English native speaker to fix several grammatical errors that I detected in the paper. I hope to provide very useful suggestions to improve the overall clarity of your study as well as the quality of your analysis. I think that my suggestions look feasible to you, and I believe you will be able to address them. Thus, please take care to do a full revision of your manuscript according to all my comments. Improvements based on my comments will be crucial for acceptance. I have some concerns and suggestions for each aspect of the manuscript. Please see below.

Abstract: I would like to suggest giving more emphasis to the results.

Lines 37 - 38: To arrange the keywords in alphabetic order.

Introduction: The paper is technically sound and the claims are convincing. However I think that some references should be updated. Please, note that the hypothesis and the predictions are unclear, you need to well explain them.

Lines 41 - 42: I think that you should add this important reference to support your sentence: “Since the 20th century, increasing warming has led to dramatic changes in the global ecological environment”. I would like to suggest:

Di Febbraro, M., et al., (2023). Different facets of the same niche: Integrating citizen science and scientific survey data to predict biological invasion risk under multiple global change drivers. Global Change Biology, 29(19), 5509-5523.

Zhang, L., et al., (2022). Where should China practice forestry in a warming world?. Global Change Biology, 28(7), 2461-2475.

Hussain, S., et al., (2020). Rice production under climate change: adaptations and mitigating strategies. Environment, climate, plant and vegetation growth, 659-686.

Lines 58 - 59: I think that you should add these important references as examples to support your sentence: “ordinary least squares (OLS) and geographically weighted regression (GWR) to provide valuable suggestions for ecosystem service management”. I would like to suggest:

Buonincontri, M. P., et al., (2023). Shedding light on the effects of climate and anthropogenic pressures on the disappearance of Fagus sylvatica in the Italian lowlands: evidence from archaeo-anthracology and spatial analyses. Science of The Total Environment, 877, 162893.

Hanski, I. (2015). Habitat fragmentation and species richness. Journal of Biogeography, 42(5), 989-993.

Lines 100 – 112: Please, explain in detail you hypothesis and predictions.

Materials and methods: In general, the methods are appropriate and the study seems well conducted, although some details deserve a bit more attention i.e., especially about the methodology and the data. All the script used in this paper must be added in the supplementary materials. Please, provide also all the link to source where you downloaded the data.

Lines 142 – 226: Please, add more details on the methodology used in this study.

Results: Well written! The figures and the tables are all informative and necessary, but not redundant, ensuring the correct comprehension of the manuscript.

Discussion: The paper discussed appropriately the context and the theme, although there is important literature not cited by the authors. I think that the authors should be discussing their results also comparing them with those already published on other species/genus/family. In fact your paper discusses findings in relation to some of the work in the field but ignores other important work that I think should be added in your discussion. Please, delete all the link to the figures. These are not the results.

I have enjoyed reading your paper; however, the manuscript must be revised by an English native speaker to fix several grammatical errors that I detected in the paper.

Author Response

Dear  Reviewer,

Thanks for your comments concerning our manuscript entitled “Quantification of spatiotemporal characteristics and identification of drivers of landscape fragmentation in karst ecosystems: An integrated analytical framework” (Manuscript ID:land-2844346). Those comments are all valuable and very helpful for revising and improving our paper. We have studied the comments very carefully and made our best efforts to enhance our paper. Our point-by- point response to the comments made by Reviewer is given below. We have also marked changes in the manuscript with green. We hope the revised manuscript will be accepted by the Reviewer. If still there are concerns, we will be happy to take care of once.

Author Response File: Author Response.docx

Reviewer 3 Report

The study is devoted to the important and actual issue of assessing the influence of anthropogenic and natural factors on landscape fragmentation. What makes the work particularly important is that it was done on the example of a karst landscape characterized by fragile ecosystems. The authors applied modern research methods. The work may be of interest for scientific substantiation of approaches to ecosystem management. However, the work has a number of important shortcomings that must be corrected for its publication to be meaningful.

1. The description of the methods needs clarification. It is necessary to explain how the coefficients for the Composite index of landscape fragmentation were obtained. It is not clear why it makes sense to combine into one index indicators between which there is negative relationship, as you write below (LPI and others).

2. Some results contradict each other (q values in Table 2 and Fig 5b) . Also, the conclusion about explanatory power of factors “is in descending order: Population density (X7) > distance to road (X9) > Soil Type(X6) > NDVI(X1) > Lithology (X5) > Elevation (X2) > Slope (X3) > Aspect(X4)”, repeated many times in the text, contradicts Table 2.

3. In a number of cases, the authors talk about the correlations found, although they do not provide correlation coefficients.

4. The manuscript is written in clear English, but some words are used poorly, some phrases are incomprehensible, there are technical errors in the text.

5. The figures are very small, difficult to perceive and some of them (Fig. 5) need clarification

Detailed comments (also see uploaded PDF file)

Line 3. Title. An unfortunate verbal construction, implying that a landscape is a component within ecosystems, while, on the contrary, the landscape is a mosaic of different ecosystems. It seems to me that it is better to use words “fragmentation of karst landscape” or "fragmentation of ecosystems in karst landscape" here

Lines 16-16. See comment above

Lines 20-22. In this form, this phrase is not very clear. After reading the text, I guess that you are talking about sequential assessment steps. It’s better to write here right away that you are talking about evaluation steps. And why are these words in quotes?

Lines 28-29. This contradicts Table 2. And the repetition of the words “population density"

Lines 31-32. These abbreviations need to be deciphered, or simply written in words, which scenarios were used

Line 42. References 1 and 2 refer to China. Therefore, it is worth either indicating China or providing links from global reviews, of which there are many

Lines 48-49. A very strange definition of landscape fragmentation. Often fragmentation leads to a simplification of the landscape due to the degradation of ecosystems and the loss of some of them. It seems to me that there is no need to define fragmentation here at all, since this is a well-known term

Line 50. Fragmentation cannot be the primary cause of ecosystem degradation, since it is itself a consequence of one or another anthropogenic impact on the landscape (development, roads, agriculture, etc.). Fragmentation is a consequence of anthropogenic impact, which specifically enhances the negative anthropogenic pressure on ecosystems

Line 51. Please check reference 10. This classic paper seems to talk about the influence of species number on ecosystem functions, not about fragmentation

Lines 63-64. This phrase is not clear. Please rephrase

Line 70. It would be helpful for readers to briefly explain the terms "rock desertification" and "stone desertification" that you use here and below.

Line 78. I think the word "which" is missing here

Line 85. The word "microcosm" has many meanings, but it is better not to use it here, since it is often used in the literature on experiments with ecological communities, denoting containers, aquariums or bottles in which experimental communities are created

Lines 100-102. see above comment on lines 20-22

Lines 103, 105, 151, 455. The 20-year time interval you studied does not allow us to talk about evolution, but only about rapid changes in the landscape due to human influence. As you rightly noted above, soil formation in karst landscapes takes many millions of years. It is on such time scales that we can talk about the evolution of landscapes.

Line 106. Karst instead karstic?

Line 118. What do you mean by streets?

Line 125. What is normal landscape? Here it is better to say “non-karst landscapes" or “other types of landscapes”

Line 131. Figure 1. The figure is not mentioned in the above text. It is highly advisable to move the panel with the graph to the Results section, where it is discussed

Lines 131-132. no spaces

Line 136. no spaces

Lines 177-179. Did you determine these coefficients yourself? Please explain how. It is not clear why it makes sense to combine into one index indicators between which there is negative relationship, as you write below (LPI and others)

Line 193. Fix letter b

Lines 228-246. Section 3.1. It is very difficult to understand the relationships between parameters and trends in their changes, looking only at maps. It would be very useful to provide correlation coefficients between them and show trends in the form of graphs

Line 229. It would be more convenient for readers if you moved the graph from Figure 1b to this section

Line 238. You can't say there's a correlation unless you've given the correlation coefficients. It would be very useful to show them in the article. In this case, you can only talk about visual hints of negative relationship

Lines 241-242. This phrase is not clear. Missing part of a sentence?

Lines 279, 281-282. q values in Table 2 and Fig 5b contradict each other. The following result contradicts q values in table 2. “Their explanatory power is in descending order: Population density (X7) > distance to road (X9) > Soil Type(X6) > NDVI(X1) > Lithology (X5) > Elevation (X2) > Slope (X3) > Aspect(X4)” As you write, q values show detectability of different drivers. Then this sequences should be completely different.

Line 281. X8 instead X9?

Lines 284-285. This is not clear. It is necessary to explain what the figure shows. 5a. Are these correlation coefficients between factors? Is it something else?

Line 329. Figure 5. What are the values shown here? Are these correlation coefficients between factors? Is it something else? What does mean ERROR MAP?

Line 333. Table 2. It would be more convenient for readers if you wrote the designations of factors in words

Line 386. This contradicts Table 2

Lines 395-396. I do not see direct correlation indicators in Fig. 4s. Clarify please

Line 409. Decipher abbreviation “PPE”

Line 419. Figure 8. The graph axes must be labeled in the figure.

Lines 446, 454. There is nothing in your data about the dependence of C sequestration on fragmentation. To reason in this vein, it is necessary to provide data on  this dependence from other publications

Line 475. This contradicts Table 2

Comments for author File: Comments.pdf

The manuscript is written in clear English, but some words are used poorly, some phrases are incomprehensible, there are technical errors in the text. See detailed comments and PDF file

Author Response

Dear  Reviewer,

Thanks for your comments concerning our manuscript entitled “Quantification of spatiotemporal characteristics and identification of drivers of landscape fragmentation in karst ecosystems: An integrated analytical framework” (Manuscript ID:land-2844346). Those comments are all valuable and very helpful for revising and improving our paper. We have studied the comments very carefully and made our best efforts to enhance our paper. Our point-by- point response to the comments made by Reviewer is given below. We have also marked changes in the manuscript with green. We hope the revised manuscript will be accepted by the Reviewer. If still there are concerns, we will be happy to take care of once.

Author Response File: Author Response.docx

Reviewer 4 Report

I have very mixed feeling about this manuscript. On one hand it presents a solid geographical approach to assess land use changes by using landscape indices and its causes. On the other hand. it claims to assess landscape fragmentation by using those methods.

By the widely accepted definition, landscape fragmentation is the physical disintegration of continuous habitats into smaller units or patches, most often caused by urban or transport network expansion. This has a wide range of environmental, social, climate change adaptation and mitigation, and biodiversity implications.

According to this definition, the manuscript deals with an analysis of land use pattern assessment and not landscape (in sense of habitat) fragmentation. Although, authors claim in the very first sentences of the abstract that “Karst ecosystems have important ecological barrier functions and high carbon sequestration potential. Accurate diagnosis and evaluation of the current status of landscape fragmentation in these ecosystems are essential to maintain ecosystem connectivity, increase carbon sinks and mitigate climate change.” The results did not show any result on connectivity (no habitat fragmentation or connectivity was analyzed), carbon sinks (yes, there is huge amount of carbon bond in the karst rock but it has no carbon sequestration potential) or climate mitigation (only possible connection is via land use emissions or carbon sequestration via photosynthesis that were not analyzed either).

I strongly suggest to re-phrase the whole concept of the paper and replace landscape fragmentation with land use pattern analysis or land use heterogeneity because this is what the paper is about. It is not even landscape diversity/heterogeneity as landscape as such comprises both natural and anthropic phenomena (land use). The natural characteristics of the studied are remained unchanged, what was changing and analyzed was land use and its spatial characteristics.

Another issue if the notion of drivers of change. Drivers or driving forces are forces that cause a change (i.e., of land use). Causality is not identical with correlation. Stable phenomena such as soil, slope, lithology can correlate with the changes but they are not drivers of change. Their change (i., e., soil erosion) can drive change in land use due to a loss of its fertility. Thus, land use changes may correlate to natural phenomena but are not driven by them (if they are not changing). Another issue is NDVI as it is a metric for quantifying the health and density of vegetation using sensor data, thus it is another representation or a descriptive parameter of land cover and it is not driver of change.

The analytical part of the manuscript has undoubtedly its merit. However, the overall concept and its interpretation must be changed in order to be acceptable from a scientific point of view. The authors should also describe why the karst region is special regarding the analyzed changes.

Author Response

Dear  Reviewer,

Thanks for your comments concerning our manuscript entitled “Quantification of spatiotemporal characteristics and identification of drivers of landscape fragmentation in karst ecosystems: An integrated analytical framework” (Manuscript ID:land-2844346). Those comments are all valuable and very helpful for revising and improving our paper. We have studied the comments very carefully and made our best efforts to enhance our paper. Our point-by- point response to the comments made by Reviewer is given below. We have also marked changes in the manuscript with green. We hope the revised manuscript will be accepted by the Reviewer. If still there are concerns, we will be happy to take care of once.

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

Well done!

Well done!

Reviewer 3 Report

The authors corrected all errors and explained unclear sections. I'm glad if my comments helped you make the article better

I only advise authors to correct the word "microcosm" in the first line of the abstract (line 15) in accordance with my previous comment

Reviewer 4 Report

Since authors either accepted my comments or provided explanation to them the manuscript  may be accepted now.