Impact of Land Transition on Landscape and Ecosystem Service Value in Northeast Region of China from 2000–2020

Round 1

Reviewer 1 Report

Thank you for the opportunity to read this text. The article presents a high scientific level. The introduction provides a good background for the research. However, the methodology, especially the description of section 2.2. should be made more detailed. For non-Chinese readers, it is not very clear what the authors mean by saying (line 118-119) "six level 1 types and twenty-five level 2 types in the land classification system". Please also provide justification for the 10-year intervals introduced. What were they caused by? The results are well presented, clearly explained. I evaluate the discussion part very highly. As far as the literature is concerned, it is a pity that so many publications refer strictly to the Chinese area. In my opinion, it is worthwhile to refer to the experience of other continents, e.g. Europe (e.g. DOI:10.3390/su11113007) . There are many studies showing the directions of land use changes and changes in the landscape. The novelty here is an attempt to link landscape change with valuation of ecosystem services. It is very good that the article includes a Limitation section. I fully agree with the authors that "ecosystem service value is also an important indicator to measure regional sustainable development" (line 411). 

Author Response

Our responses to the Reviewer #1

Comments and Suggestions for Authors

Reviewer# 1, comment 1: Thank you for the opportunity to read this text. The article presents a high scientific level. The introduction provides a good background for the research. However, the methodology, especially the description of section 2.2. should be made more detailed. For non-Chinese readers, it is not very clear what the authors mean by saying (line 118-119) "six level 1 types and twenty-five level 2 types in the land classification system".

Response: We are very grateful to the reviewer for the high evaluation of this manuscript, and we are very sorry that the part 2.2 is not detailed enough. In the revised manuscript, we provide a more detailed description. Especially, the words "six level 1 types and twenty-five level 2 types in the land classification system" is modified below, namely,

“The land classification system includes six first types, namely, cultivated land, forest land, grassland, water area, construction land and unused land. Then, the six first types are further divided into 25 secondary types”. (page 4, lines 145-147, in the revised manuscript).

 

Reviewer# 1, comment 2: Please also provide justification for the 10-year intervals introduced. What were they caused by?

Response: we are very grateful to the reviewer for the suggestion. The reason for the 10-year intervals introduced is added in the revised manuscript, namely,

“We obtain the corresponding data for the ten-year interval from 2000 to 2020, because we participate in the data production of 2010 and 2020 on the basis of obtaining the basic data of 2000”. (page 4, lines 147-149, in the revised manuscript). This means that we have the right to use this data, and there will be no data copyright problem without permission. We are very grateful to the reviewer for the reminder to improve this issue, thanks.

 

Reviewer# 1, comment 3: The results are well presented, clearly explained. I evaluate the discussion part very highly.

Response: We are very grateful to the reviewer for the positive comments on results and discussion sections in the manuscript.

 

Reviewer# 1, comment 4: As far as the literature is concerned, it is a pity that so many publications refer strictly to the Chinese area. In my opinion, it is worthwhile to refer to the experience of other continents, e.g. Europe (e.g. DOI:10.3390/su11113007). There are many studies showing the directions of land use changes and changes in the landscape.

Response: We agree with the reviewer's suggestion, and we try to obtain the refer worthwhile, and the literature from other continents, e.g. Europe (e.g. DOI:10.3390/su11113007) is added in the revised manuscript. (page 17, lines 536-537, in the revised manuscript).

 

Reviewer# 1, comment 5: The novelty here is an attempt to link landscape change with valuation of ecosystem services. It is very good that the article includes a Limitation section. I fully agree with the authors that "ecosystem service value is also an important indicator to measure regional sustainable development" (line 411).

Response: We are very grateful to the reviewer for the positive comments on the manuscript.

We are very grateful to the reviewer for the comments, which have constructively improved the quality of the manuscript.

 

Author Response File: Author Response.pdf

Reviewer 2 Report

I feel that the paper is well written. However, there are some points to be revised.

1. As the Land is the SSCI journal, how about making a literature review section about ecosystem services value.
2. Methodology section is a little complex. How about suggesting detailed explanation of Table 1, 2, 3. And making the diagram of research process will be helpful to understand your study, easily.
3. Please insert the explanation of legend in figure 6.

Author Response

Reviewer 2

Comments and Suggestions for Authors

I feel that the paper is well written. However, there are some points to be revised.

Response: We are very grateful to the reviewer for the high evaluation of the manuscript, and we are very grateful to the reviewer for the comments. These comments are replied by point to point below.

 

Reviewer# 2, comment 1: As the Land is the SSCI journal, how about making a literature review section about ecosystem services value.

Response: We are very grateful to the reviewer for the comment and agree with the comment. Considering land as the background Journal of SSCI, a literature review section about ecosystem services value is added in the introduction section of the revised manuscript, namely,

“Research on ecosystem service value, Daily [37] provides the early concept and framework, which lays the foundation for the follow-up research. Like, the ecosystem service value is monetized [38], and the annual average ecosystem service value is calculated quantitatively [39]. And the ecosystem service is usually seen as the benefits obtained by human beings from the ecosystem, including supply service (i.e., providing food and water), regulation service (i.e., controlling floods and diseases), cultural service (i.e., spiritual, entertainment and cultural benefits) and support service (i.e., maintaining the nutrient cycle of the earth's living environment). These ecosystem services not only provide human beings with raw materials for production and life such as food and medicine, but also create and maintain the life support system of the earth and form the necessary environmental conditions for human survival. At the same time, it also provides leisure, entertainment and aesthetic enjoyment for human life [40-42]. In China, the most commonly used ecosystem accounting method is the equivalent factor method proposed by Xie Gaodi [43,44], which fully considers the situation of China's ecosystem and gives different equivalent factors/values through the combination of different ecological condition and land use/cover changes, but in this method, construction land is used as bare land. In view of the deficiency that the construction land is regarded as bare land in this method, we improve a new calculation method, to present the more real ecosystem ser-vice as well as its change”. (page 2, lines 68-86, in the revised manuscript).

 

Reviewer# 2, comment 2: Methodology section is a little complex. How about suggesting detailed explanation of Table 1, 2, 3. And making the diagram of research process will be helpful to understand your study, easily.

Response: We agree with the reviewer’s suggestion and add the detailed explanation, namely,

For table 1, we add more contents, namely,

“Landscape index is applied to describe the effect of landscape pattern on ecological process [10]. Through the quantitative analysis of landscape index, we can observe the dynamic change of various landscape elements in space and time. Generally, the landscape survey is divided into three different scales, and the patch level is often overlooked when land use dynamics are analyzed. The calculation of landscape pattern index mainly uses the landscape analysis software fragstats4.2. Based on the user guide document, we comprehensively analyze the features of the landscape dominance, diversity, and fragmentation from the view of the area/side length, shape, aggregation/distribution, connectivity and diversity of land use pattern in each period from the type level and from landscape level, a total of seven indicators are selected. When we select these indexes, we fully consider the relevance of the landscape index, too many indexes always lead to redundancy, and the single landscape index can not comprehensively summarize the landscape pattern of the study area [13,49]. We use as few indexes as possible to fully express the change of landscape according to the user guide document and the meaning of landscape ecological indexes. These selected indexes are shown in Table 1, including the names, abbreviations, formulas and meanings”. (pages 4-5, lines 169-184, in the revised manuscript).

 

For table 2, we add the innovation of this method in this study, namely,

“However, in their ecosystem value assessment from previous literature, construction land, including urban, rural land, and industrial and mining land, is treated as bare land, which often leads to the underestimation. By investigating the land cover distributions within construction land in Northeast China, we provide a new ecosystem service value calculation of construction land. In the actual survey, the impervious surface land of the construction land is about two-thirds, the other one-third consists of the equal woodland and grassland, and the water body can be basically ignored. Therefore, from the perspective of land cover, we put forward a new method to calculate the ecosystem service value of construction land in Northeast China, that is, the calculation of construction land is 4/6 bare soil (impervious surface land) + 1/6 grassland + 1/6 forest land”. (page 5, lines 190-200, in the revised manuscript).

 

For table 3, we expand more contents, namely,

“Then, we take the suitable value of the net profit of grain production per unit area to evaluate the equivalent weight factor of ecosystem service in the light of the ecosystem situation in Northeast China, so that it can match with the ecosystem assessment in Northeast China. In the process of ecosystem value matching, we have made full use of the statistical data of grain sown area and grain net profit in Northeast China from 2000 to 2020, considering that rice, soybean, corn and wheat are the main food crops in Northeast China and the regional background of land changes in sowing areas. The value of ecosystem service in Northeast China is shown below as well as the diverse types of land use for the carriers of ecosystem service (Table 3)”. (page 6, lines 211-219, in the revised manuscript).

 

And to understand the research process of this manuscript more easily, we add a summary in the method section, namely,

“To explore the latest land use pattern and its accurate ecosystem service value in Northeast China, land-use change detection technology is first calculated the land use change from 2000 to 2020 and analyzed the new land cover phenomenon of these changes in this region. Then, landscape index changes are guided as few ecological indexes as possible to fully express the change of landscape at the different levels. Finally, a new ecosystem service value calculation of construction land is created according to the internal land cover of construction land in Northeast China, which is used to make up for the current underestimation of ecosystem service value of construction land in this region. Please see the following section for detailed method”. (pages 3-4, lines 131-139, in the revised manuscript).

 

Reviewer# 2, comment 3: Please insert the explanation of legend in figure 6.

Response: We are very grateful to the reviewer for the suggestion and we insert the explanation of legend in figure 6 in the revised manuscript, namely,

“For the explanation of legend, I, II, III, IV and V represent the different levels in the ecosystem service values, with low value region, sub-low value region, median value region, sub-high value region and high value region, respectively”. (page 13, lines 388-391, in the revised manuscript).

We are very grateful to the reviewer for the comments, which have constructively improved the quality of the manuscript.

 

Author Response File: Author Response.pdf

Reviewer 3 Report

Aim of the work is to propose an integrated methodology of land use change monitoring - landscape analysis - ecosystem service measurement  fot the impact of land evolution on landscape and ecosystem service value in northeast region of China from 2000-2020. Some suggestions are provided in order to improve the work:

• Abstract
  • Reduce the results section by summarizing it in the main results
  • addd the utility of the proposed analysis
  • add the innovative contribution provided
• Introduction
  • It could be useful to add a brief description of what ecosystem services are. Some useful reference on this could be: Morano, P., Guarini, M. R., Sica, F., & Anelli, D. (2021, September). Ecosystem Services and Land Take. A Composite Indicator for the Assessment of Sustainable Urban Projects. In International Conference on Computational Science and Its Applications (pp. 210-225). Springer, Cham and Ding, X. H., Zhao, W., Zhong, W. Z., & Xing, Z. B. (2014). Assessing the impacts of urbanization on the ecosystem services of city in northwestern China: case study of xi'an. In Advanced Materials Research (Vol. 864, pp. 1070-1077). Trans Tech Publications Ltd.
• Methods
  • add, if possible, an image representing the existent land use type and associated ecosystem services values
  • add, if possible, a map representing the spatial distribution of each index calculated in the area (also as supplementary files)
• Conclusions
  • add the utility of the results

Author Response

Reviewer 3

Comments and Suggestions for Authors

Aim of the work is to propose an integrated methodology of land use change monitoring - landscape analysis - ecosystem service measurement for the impact of land evolution on landscape and ecosystem service value in northeast region of China from 2000-2020. Some suggestions are provided in order to improve the work:

Response: we are very grateful to the reviewer for the positive comments on the manuscript, and we reply to the suggestions by point to point to improve our work. Please see the below.

 

Reviewer# 3, comment 1: Abstract

(1) Reduce the results section by summarizing it in the main results

Response: We agree with the reviewer's suggestion.

(1) we revised the results by summarizing the main contents (Total 151 words) in the revised manuscript, namely,

“Results show that: (1) New evidence is observed that the cultivated land in Northeast China has been reduced, with 309,610.33 km² in 2010 and 309,417.52 km² in 2020, showing net change area of -192.82 km². This is the opposite of the increase of cultivated land compared to the past. (2) Shannon's diversity index displays an upward trend, with the richer landscape types and higher fragmentation in the whole region. In addition, contagion index reduced, with a total decrease of 1.93, indicating that the patches distribute intermittently and the agglomeration degree of these patches are weakened. (3) More precise ecosystem service value is assessed, with 2,868.39 billion yuan in 2000 to 2,814.06 billion yuan in 2020, and the hydrological regulation, climate regulation and soil conservation play a dominant role in these functions in 2020. Spatial pattern of ecosystem service value is high-rank in the Northwest and Southeast, and low-rank in other directions”. (page 1, lines 24-34, in the revised manuscript).

 

(2) add the utility of the proposed analysis

Response: we add the utility of the study in the revised manuscript, namely,

“to provide the more suitable ecosystem assessment application for Northeast China”. (page 1, line 36, in the revised manuscript).

 

(3) add the innovative contribution provided

Response: we add the innovative of the study in the revised manuscript, namely,

“This study provides the new results on land change and landscape pattern and creates an improved ecosystem service value assessment method in Northeast China”. (page 1, lines 34-35, in the revised manuscript).

 

Reviewer# 3, comment 2: Introduction

It could be useful to add a brief description of what ecosystem services are. Some useful reference on this could be: Morano, P., Guarini, M. R., Sica, F., & Anelli, D. (2021, September). Ecosystem Services and Land Take. A Composite Indicator for the Assessment of Sustainable Urban Projects. In International Conference on Computational Science and Its Applications (pp. 210-225). Springer, Cham and Ding, X. H., Zhao, W., Zhong, W. Z., & Xing, Z. B. (2014). Assessing the impacts of urbanization on the ecosystem services of city in northwestern China: case study of xi'an. In Advanced Materials Research (Vol. 864, pp. 1070-1077). Trans Tech Publications Ltd.

Response: We are very grateful to the reviewer for providing the valuable references. We make full use of these literature to add a description of what ecosystem services are in the introduction, namely, “And the ecosystem service is usually seen as the benefits obtained by human beings from the ecosystem, including supply service (i.e., providing food and water), regulation service (i.e., controlling floods and diseases), cultural service (i.e., spiritual, entertainment and cultural benefits) and support service (i.e., maintaining the nutrient cycle of the earth's living environment). These ecosystem services not only provide human beings with raw materials for production and life such as food and medicine, but also create and maintain the life support system of the earth and form the necessary environmental conditions for human survival. At the same time, it also provides leisure, entertainment and aesthetic enjoyment for human life [40-42]”. (page 2, lines 71-80, in the revised manuscript).

 

Reference:

40. Morano, P.; Guarini, M.R.; Sica, F.; Anelli, D. Ecosystem Services and Land Take. A Composite Indicator for the Assessment of Sustainable Urban Projects. In Proceedings of the International Conference on Computational Science and Its Applications, 2021; pp. 210-225.
41. Ding, X.H.; Zhao, W.; Zhong, W.Z.; Xing, Z.B. Assessing the impacts of urbanization on the ecosystem services of city in northwestern China: case study of xi'an. In Proceedings of the Advanced Materials Research, 2014; pp. 1070-1077.
42. Daily, G. What are ecosystem services. Global environmental challenges for the twenty-first century: Resources, consumption and sustainable solutions 2003, 227-231. (pages 18-19, lines 603-608, in the revised manuscript).

 

Reviewer# 3, comment 3: Methods

add, if possible, an image representing the existent land use type and associated ecosystem services values, add, if possible, a map representing the spatial distribution of each index calculated in the area (also as supplementary files)

Response: We are very grateful to the reviewer for the comment and agree with the reviewer's suggestion. We try to stack the land use type and associated ecosystem services values together, to make it an image. It is a pity that the result map of superposition is complex and difficult to understand, due to too much information on a map. We have to divide the land use map and ecosystem service value map into two maps, and then put these two maps in the conclusion analysis part to analyze the change of land dynamics and ecosystem service values. And a map representing the spatial distribution of each index calculated in the area is also tested, we didn't get a better spatial clarity map. Meanwhile, to improve the quality of the method, we add a summary description of the method to make the method part easy to understand, namely, “To explore the latest land use pattern and its accurate ecosystem service value in Northeast China, land-use change detection technology is first calculated the land use change from 2000 to 2020 and analyzed the new land cover phenomenon of these changes in this region. Then, landscape index changes are guided as few ecological indexes as possible to fully express the change of landscape at the different levels. Finally, a new ecosystem service value calculation of construction land is created according to the internal land cover of construction land in Northeast China, which is used to make up for the current underestimation of ecosystem service value of construction land in this region. Please see the following section for detailed methods (pages 3-4, lines 131-139, in the revised manuscript)”. Furthermore, we have described the method part more detail, such as the description of each table. We hope that such modification can meet the regret left by the lack of space map in part of the method. We sincerely thank the reviewer for this suggestion.

 

Reviewer# 3, comment 4: Conclusions

add the utility of the results

Response: we add the utility of the results in the conclusion section in the revised manuscript, namely,

“Overall, this study provides land change, landscape pattern and ecosystem service value assessment in the period of 2000-2020. These three aspects can bring relevant applications in Northeast China. The finding of the reduction of cultivated land area from 2010-2020 provides temporal and spatial data for regional cultivated land protection and food security. The landscape pattern change is conducive to the study of landscape ecological corridor and residential ecological environment in this region. The change of ecosystem service value is beneficial for the assessment of natural environment quality such as the cultural service (i.e., spiritual, entertainment and cultural benefits) and support service (i.e., maintaining the nutrient cycle of the earth's living environment). Therefore, this study provides the more suitable ecosystem assessment utility for Northeast China”. (pages 15-16, lines 500-509, in the revised manuscript).

We are very grateful to the reviewer for the comments, which have constructively improved the quality of the manuscript.

 

Author Response File: Author Response.pdf

Reviewer 4 Report

         The research topic has certain practical significance. However, the academic significance of this study is not clear. Meanwhile, it lacks a rigorous theoretical analysis framework, which is the biggest shortcoming of this study. Specific comments are as follows: 

         (1) The marginal contribution of research is not clear. The present introduction only states the research objective, and does not clearly indicate the marginal contribution of this research.  Is it from a research perspective? Research methods? Or theoretical framework? 

         (2) Because the research lacks a rigorous theoretical analysis framework, there is no basis for the selection of indicators. The paper's analysis is more like data-driven technical reports than rigorous academic research papers. The author should select indicators under the guidance of strict theoretical analysis framework, and the author should strictly research hypotheses. 

Author Response

Reviewer 4

Comments and Suggestions for Authors

Reviewer# 4, comment 1: The research topic has certain practical significance. However, the academic significance of this study is not clear. Meanwhile, it lacks a rigorous theoretical analysis framework, which is the biggest shortcoming of this study. Specific comments are as follows:

Response: We thank the reviewer for the suggestions and agree with the comments. We are very sorry that the academic framework is not clear in the original manuscript, and we improve the academic framework through modification. This study focuses on the effects of landscape and ecosystem services caused by land change. The research framework mainly includes three parts: Firstly, we analyze the new land change phenomenon based on the latest land data. Secondly, the landscape evolution process is calculated through land data. Finally, we propose an improved ecosystem service method to calculate the regional ecosystem service value, taking land use data as one of the data sources. To make the research framework clear, we have added the following contents to the revised manuscript, namely,

“To explore the latest land use pattern and its accurate ecosystem service value in Northeast China, land-use change detection technology is first calculated the land use change from 2000 to 2020 and analyzed the new land cover phenomenon of these changes in this region. Then, landscape index changes are guided as few ecological indexes as possible to fully express the change of landscape at the different levels. Finally, a new ecosystem service value calculation of construction land is created according to the internal land cover of construction land in Northeast China, which is used to make up for the current underestimation of ecosystem service value of construction land in this region. Please see the following section for detailed method”. (pages 3-4, lines 131-139, in the revised manuscript).

Also, we make other modifications in the revised manuscript to improve the research framework. We are very grateful to the reviewer for the valuable suggestions on the theoretical analysis framework to improve the quality of the manuscript and correct shortcoming of this study.

 

And we response to the specific comments by point to point below.

 

Reviewer# 4, comment 2: (1) The marginal contribution of research is not clear. The present introduction only states the research objective, and does not clearly indicate the marginal contribution of this research.  Is it from a research perspective? Research methods? Or theoretical framework?

Response: We are very sorry that the contribution of the research is not clear in the original manuscript. The contribution of this study includes two aspects. One is to analyze the new change phenomenon and ecological landscape pattern based on the latest land data; The other is an improved algorithm for ecosystem service value in Northeast China is proposed. To make the marginal contribution of research clear in the revised manuscript, we add the following contents in the abstract section, namely,

“This study provides the new results on land change and landscape pattern and creates an improved ecosystem service value assessment method in Northeast China, to provide the more suitable ecosystem assessment application for Northeast China”. (page 1, lines 34-36, in the revised manuscript).

 

Reviewer# 4, comment 3: (2) Because the research lacks a rigorous theoretical analysis framework, there is no basis for the selection of indicators. The paper's analysis is more like data-driven technical reports than rigorous academic research papers. The author should select indicators under the guidance of strict theoretical analysis framework, and the author should strictly research hypotheses.

Response: We thank the reviewer for the suggestion and agree with the comment. To improve the academic quality, we revise the manuscript in the analysis of “land use change monitoring - landscape analysis - the ecosystem service value assessment” during the revision period. Furthermore, we add the innovation of the study in the method section in the revised manuscript, namely,

“However, in their ecosystem value assessment from previous literature, construction land, including urban, rural land, and industrial and mining land, is treated as bare land, which often leads to the underestimation. By investigating the land cover distributions within construction land in Northeast China, we provide a new ecosystem service value calculation of construction land. In the actual survey, the impervious surface land of the construction land is about two-thirds, the other one-third consists of the equal woodland and grassland, and the water body can be basically ignored. Therefore, from the perspective of land cover, we put forward a new method to calculate the ecosystem service value of construction land in Northeast China, that is, the calculation of construction land is 4/6 bare soil (impervious surface land) + 1/6 grassland + 1/6 forest land”. (page 5, lines 190-200, in the revised manuscript).

 

Also, we discuss the differences between the original method and our method in the evaluation of ecosystem service value in the discussion section, namely,

“4.2 The comparison comes from the improved method in this study and the conventional method

This study not only provides new research results in land change and landscape pattern, but also provides the improved method of ecosystem service value in Northeast China. In previous relevant studies, the conventional method usually chooses to ignore the ecosystem service value of construction land (i.e., set as 0 value) and rely on the change of the ecological value of dominant land cover, such as the ecosystem value evaluation of Sanjiang Plain in Northeast China [61]. Also, some other scholars also ig-nore this problem [62,63]. In the previous literature, construction land [61], including urban, rural land, and industrial and mining land, is always treated as bare land, which often leads to the underestimation of the ecosystem service value in Northeast China. In the contexts of large-scale construction land expansion, ecological elastic cities, livable cities and rural revitalization policies [64,65] have helped to increase the vegetation within the construction land area. Also, the impact of construction land on regional eco-logical functions such as purified environment, biodiversity and aesthetic landscape, needs the ecosystem value assessment. Therefore, by investigating the land cover dis-tributions within construction land in Northeast China, we provide a new ecosystem service value calculation of construction land. In the actual survey, the impervious sur-face land of the construction land is about two-thirds, the other one-third consists of the equal woodland and grassland, and the water body can be basically ignored [66]. There-fore, from the perspective of land cover, we put forward a new method to calculate the ecosystem service value of construction land in Northeast China, that is, the calculation of construction land is 4/6 bare soil (impervious surface land) + 1/6 grassland + 1/6 forest land. This means that we consider the vegetation factors inside the construction land, to make the ecosystem assessment more accurate. In addition to the comparison between the method in this study and traditional method, we also conduct the comparative ex-periments in the study area according to these two methods. We find that: the total eco-system service value in Northeast China was 2,774.99 billion yuan, 2,725.57 billion yuan and 2,702.96 billion yuan in 2000, 2010 and 2020 from conventional method, respectively, while our method obtain more ecosystem service, with more values of 93.39 billion yuan, 98.59 billion yuan and 111.10 billion yuan in 2000, 2010 and 2020. Therefore, our research can obtain more accurate results compare to traditional method in Northeast China”. (page 14, lines 417-447, in the revised manuscript).

We are very grateful to the reviewer for the comments, which have constructively improved the quality of the manuscript.

 

 

Author Response File: Author Response.pdf

Reviewer 5 Report

Overall Comments

The paper approaches the land-use transition and the ecosystem service value in the northeast region of China from 2000 to 2020. As a product, the results show an important asset that can be used as a policy instrument and that could be very relevant for the studied region. However, in the final sub-topic of the Discussion section, the authors argue in a way that these results are preliminary, and that concerns me because I am not sure if that means that the results are in construction and can be further altered (i.e., with new analyses). If this is not the case, the authors must review their writing clearly to readers. Also, the importance and implications of giving value to nature are not clear. This is crucial for this research and must be clearly shown. They must revise some other points for the paper to be considered for publication:

1. English writing must be proofread mainly in the Introduction and Methodology sections. Also, the writing style must be standardised. It would be better to use the first person in the Methodology and Results sections, but if you prefer writing in the third person, that must be standardised.
2. The term “land evolution” is not usual. I believe they used it as “land transition”, so if a) this is the case, just use “land transition”; or b) this is not the case, clearly explain and reference in the introduction what does “land evolution” means.
3. Clearly show the aims of the paper even in the Abstract.
4. Monetary values could be also given in USD, at least as a footnote. This would increase the visibility of the paper.
5. For large numbers, the thousands separator must be included. Also, add the unit of all writing values throughout the text.
6. In the Introduction and Discussion sections, it is not clear to me what is the importance of giving a monetary value to nature in this study region. In the Introduction section, the authors must clearly show this importance, and in the Discussion section they must explain what their results are showing under the scientific literature - What do these values represent for China? How can this assessment help regional environmental management?
7. The Land Use and Land Cover dataset are from the “data centre of resources and environment, science of the Chinese Academy of Sciences”, so I do not believe that the authors can call as “new” evidence since they were not produced in this (or for this) research.
8. All landscapes indexes must be referenced, and the author should also explain in the Methodology section what are the meanings of the results got from these indexes. The authors argue in the Methodology that “too many indexes always lead to redundancy”, so how it was decided that seven indexes were not “too many”?
9. In the Discussion section, the 4.2 and 4.3 subsections are not a scientific discussion of the data. The authors must use this section to explain the behaviour of the results and/or compare their results with other published research.

 

Specific comments

Line 52: It is not clear what “focused environmental issues” means.

Line 58: It is not clear what “make the evaluation accuracy of land use need to be improved” means.

Lines 61-66: The authors should also show what is the spatial resolution of this dataset, so readers can compare it with the previously mentioned ones.

Line 68: I do not see why the used software should be mentioned in the Introduction section.

Lines 71-72: There is no explanation of the importance of given value to nature, this is an important part of the research, so the authors have to better address this topic.

Line 76: It is not clear what “we localized and revised” means.

Line 84: What is still lacking?

Line 85: It is not clear what “law” means.

Line 86: If the dataset was produced by another institution, how do you provide a “new land-use change phenomenon”? And I believe that you mean “describe” instead of “provide”, right?

Line 102 and forward: The authors mentioned a statistic, so these statistics must be referenced.

Line 109: What are the “one core and five strategies”?

Figure 1: The boundaries shown in Figure 6 should also be given here since you studied each of these locations.

Line 140: I do not think that you should use a word such as “always” in scientific research.

Table 1: You must reference the literature from where you extracted each of these formulas. And describe the meaning of each variable.

Line 171: Reference the “relevant research” mentioned.

Table 3: What is the monetary unit used? Give values also in USD or at least the conversion rate at the time of publication of the paper.

Figure 3: What is the unit on the left axis? What does “law” mean here?

Lines 270-274: Sound like a discussion of the results.

Lines 300-303: Sound like methodology.

Figure 5: What is the unit on the left axis?

Lines 331-335: Should be in the Methodology section. It is also difficult to track the numbers I, II, III, IV and V throughout the text. It would be easier to read if you use acronyms for each level. Also, in the Methodology section, it must be presented what each of these levels means.

Lines 340- 353: I suggest that this discrimination per District could be turned into a table, where the authors could also give the mean results per District.

Discussion section: The titles of the subsection are not clear.

Line 361 and 363: It is not clear what “land reclamation” means.

Subsection 4.2: It is entirely written as results – no discussion is made.

Author Response

Reviewer 5

Comments and Suggestions for Authors

Reviewer# 5, comment 1: Overall Comments

(1) The paper approaches the land-use transition and the ecosystem service value in the northeast region of China from 2000 to 2020. As a product, the results show an important asset that can be used as a policy instrument and that could be very relevant for the studied region. (2) However, in the final sub-topic of the Discussion section, the authors argue in a way that these results are preliminary, and that concerns me because I am not sure if that means that the results are in construction and can be further altered (i.e., with new analyses). If this is not the case, the authors must review their writing clearly to readers. (3) Also, the importance and implications of giving value to nature are not clear. This is crucial for this research and must be clearly shown. They must revise some other points for the paper to be considered for publication:

Response: We are very grateful to the reviewer for the comments and we agree with these suggestions.

(1) We are very grateful to the reviewer for the positive comments on the manuscript.

(2) We are very sorry for the unclear description in the final sub-topic of the Discussion section. In fact, the results are not preliminary and not further altered (i.e., with new analyses). To make the description clearer in the revised manuscript, we have made extensive modifications to the discussion section, the first sub-topic is used to analyze new land discoveries. At the same time, we rewrite the second sub-topic and compare the innovation of this method with the previous method. Finally, we discuss the deficiencies and the plan for the next step in the third sub-topic. (pages 13-15, lines 394-469, in the revised manuscript).

(3) We are very grateful to the reviewer for the reminder. In order to show the importance and implications of giving value to nature, we first add the application of this study at the end of the abstract section, namely,

“This study provides the new results on land change and landscape pattern and creates an improved ecosystem service value assessment method in Northeast China, to provide the more suitable ecosystem assessment application for Northeast China.” (page 1, lines 34-36, in the revised manuscript).

Then, at the end of the conclusion section, we add the applicability of the whole manuscript in three aspects, namely,

“Overall, this study provides land change, landscape pattern and ecosystem service value assessment in the period of 2000-2020. These three aspects can bring relevant applications in Northeast China. The finding of the reduction of cultivated land area from 2010-2020 provides temporal and spatial data for regional cultivated land protection and food security. The landscape pattern change is conducive to the study of landscape ecological corridor and residential ecological environment in this region. The change of ecosystem service value is beneficial for the assessment of natural environment quality such as the cultural service (i.e., spiritual, entertainment and cultural benefits) and support service (i.e., maintaining the nutrient cycle of the earth's living environment). Therefore, this study provides the more suitable ecosystem assessment utility for Northeast China”. (pages 15-16, lines 499-508, in the revised manuscript).

 

Reviewer# 5, comment 2: English writing must be proofread mainly in the Introduction and Methodology sections. Also, the writing style must be standardised. It would be better to use the first person in the Methodology and Results sections, but if you prefer writing in the third person, that must be standardised.

Response: We are very grateful to the reviewer for the comment, and we agree with the suggestion. In the revised manuscript, we proofread all grammatical structures and languages to improve the writing quality of the manuscript. Meanwhile, in the methodology and results sections, we try to use the first person to express the contents to achieve the standardization of writing style.

 

Reviewer# 5, comment 3: The term “land evolution” is not usual. I believe they used it as “land transition”, so if a) this is the case, just use “land transition”; or b) this is not the case, clearly explain and reference in the introduction what does “land evolution” means.

Response: We thank the reviewer for the suggestion, and we are very sorry for the inaccuracy of the description. In the revised manuscript, all the words “land evolution” are replaced by “land transition”.

 

Reviewer# 5, comment 4: Clearly show the aims of the paper even in the Abstract.

Response: We are very sorry that the research goal of this paper is not clear. In the revised manuscript, we make extensive modifications to the abstract section, to clearly express the aim, method, findings and significance of this study, namely,

“Scientific issue and aim: (Drastic land pattern change has taken place in the northeast region of China, which may have a significant impact on landscape and ecosystem service. Up to now, insufficient renewal of land use pattern may limit the latest assessment of landscape and ecosystem service value. Meanwhile, the adaptive ecosystem service value improvement method should be established). Method: (To solve this issue, an integrated methodology of land use change monitoring - landscape analysis - the promoted ecosystem service measurement is established.) Findings: (Results show that: (1) A new evidence is observed that the cultivated land in Northeast China has been reduced, with 309610.33 km² in 2010 and 309417.52 km² in 2020, showing the net change area of -192.82 km². This is the opposite of the increase of cultivated land compared to the past. (2) Shannon's diversity index displays an upward trend, with the richer landscape types and higher fragmentation in the whole region. In addition, contagion index reduced, with a total decrease of 1.93, indicating that the patches distribute intermittently and the agglomeration degree of these patches are weakened. (3) More precise ecosystem service value is assessed, with 2868.39 billion yuan in 2000 to 2814.06 billion yuan in 2020, showing the negative impact on environments, and the hydrological regulation, climate regulation and soil conservation play a dominant role in these functions in 2020. Spatial pattern of ecosystem service value is high-rank in the Northwest and Southeast, and low-rank in other directions.) Innovation and importance: (This study provides the new results on land change and landscape pattern, and creates an improved ecosystem service value assessment method in Northeast China, to provide the more suitable ecosystem assessment application for Northeast China.)”. (page 1, lines 19-36, in the revised manuscript).

 

Reviewer# 5, comment 5: Monetary values could be also given in USD, at least as a footnote. This would increase the visibility of the paper.

Response: We are very grateful to the reviewer for the comment, and we agree with the suggestion. Monetary values in USD would increase the visibility of the paper, and we analyze this deficiency in the section of the 4.3 Deficiencies and suggestions in the revised manuscript, namely,

“However, the monetary values are displayed in Chinese yuan. Maybe, the monetary values in USD increase the visibility of the paper. Considering the fluctuation and uncertainty of RMB and US dollar exchange rate from 2000 to 2020 [67], this study use the Chinese yuan. And we will overcome the exchange rate problem between RMB and US dollar in future research and unify it into US dollar.” (page 15, lines 460-464, in the revised manuscript).

 

Reviewer# 5, comment 6: For large numbers, the thousands separator must be included. Also, add the unit of all writing values throughout the text.

Response: We are very grateful to the reviewer for the comment, and we agree with the suggestion. For all the large numbers, the thousands separator is added, and the unit of all writing values throughout the text is also added in the revised manuscript.

 

Reviewer# 5, comment 7: In the Introduction and Discussion sections, it is not clear to me what is the importance of giving a monetary value to nature in this study region. (1) In the Introduction section, the authors must clearly show this importance, and (2) in the Discussion section they must explain what their results are showing under the scientific literature - What do these values represent for China? How can this assessment help regional environmental management?

Response: We are very grateful to the reviewer for the comment, and we agree with the suggestion. (1) To make this clear, we add the contents in the introduction section to show the importance of giving a monetary value to nature in Northeast China, namely,

“In the early days, Northeast China was called the “Northern Wilderness”, which was sparsely populated, backward economy and most of the undeveloped natural environment. Later, it became “Beidacang”, China's grain base, and one of China's heavy industry centers. In the process of economic development, especially since 2000, significant land changes have taken place in regional ecosystem services, such as the loss of large number of natural wetlands. The study of ecosystem service value in this region plays an important role in analyzing the natural supply, ecological regulation and service, culture”. (page 2, lines 87-93, in the revised manuscript).

 

(2) We are very grateful to the reviewer for the comments, and we are very sorry that the description is not clear in the original manuscript. To clarify this issue, we add the following contents, namely, “Our results show that the value of ecosystem services in Northeast China shows a decreasing trend during the study period, with the values of 2,868.39 billion yuan in 2000 to 2,814.06 billion yuan in 2020 (Fig.5). This result is mainly due to the loss of forest land and grassland with high ecosystem services and the expansion of urban, rural, industrial and mining land with low ecosystem services (Fig.2). Our results have similar trends with previous literature, namely, the value of ecosystem services in most regions of China has decreased under the background of construction land expansion since 2000. (pages 14-15, lines 449-455, in the revised manuscript).

For the regional environmental management, we add the contents, namely,

“The change of ecosystem service value is beneficial for the assessment of natural environment quality such as the cultural service (i.e., spiritual, entertainment and cultural benefits) and support service (i.e., maintaining the nutrient cycle of the earth's living environment). Therefore, this study provides the more suitable ecosystem assessment utility for Northeast China”. (pages 15-16, lines 505-509, in the revised manuscript).

 

Reviewer# 5, comment 8: (1) The Land Use and Land Cover dataset are from the “data centre of resources and environment, science of the Chinese Academy of Sciences”, so I do not believe that the authors can call as “new” evidence since they were not produced in this (or for this) research.

(2) All landscapes indexes must be referenced, and the author should also explain in the Methodology section what are the meanings of the results got from these indexes. The authors argue in the Methodology that “too many indexes always lead to redundancy”, so how it was decided that seven indexes were not “too many”?
Response: We are very grateful to the reviewer for the comments, and we agree with the suggestions.

For (1): We are very sorry that the description in the original manuscript is not clear. In fact, we are members of the land use data production team, and I'm also a guest staff in “data centre of resources and environment, science of the Chinese Academy of Sciences”, which belongs to the Institute of Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences. This is the first time that we report this data, and thus the results are new. To make this clear, first, I (i.e., the corresponding author) add the institution, namely,

“Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China”, to indicate that I belong to the data production institution. (page 1, lines 8-9, in the revised manuscript).

Then, we add more detailed information in this section of the revised manuscript, namely,

“Among them, the land use dataset comes from the data center of resources and environment, science of the Chinese Academy of Sciences. And we are the member of data production that the data is first used (i.e., the land use data in the year 2020)”. (page 4, lines 142-145, in the revised manuscript).

 

For (2): we are very sorry that the description of the original manuscript is not clear. These indexes are selected from the user guide document and the meaning of landscape ecological indexes. To make this problem clear, we revise it below, namely,

“Landscape index is applied to describe the effect of landscape pattern on ecological process [10]. Through the quantitative analysis of landscape index, we can observe the dynamic change of various landscape elements in space and time. Generally, the land-scape survey is divided into three different scales, and the patch level is often overlooked when land use dynamics are analyzed. The calculation of landscape pattern index mainly uses the landscape analysis software fragstats4.2. Based on the user guide document, we comprehensively analyze the features of the landscape dominance, diversity, and fragmentation from the view of the area/side length, shape, aggregation/distribution, connectivity and diversity of land use pattern in each period from the type level and from landscape level, a total of seven indicators are selected. When we select these indexes, we fully consider the relevance of the landscape index, too many indexes always lead to redundancy, and the single landscape index can not comprehensively summarize the landscape pattern of the study area [13,49]. We use as few indexes as possible to fully express the change of landscape according to the user guide document and the meaning of landscape ecological indexes. These selected indexes are shown in Table 1, including the names, abbreviations, formulas and meanings”. (pages 4-5, lines 169-184, in the revised manuscript)

 

Reviewer# 5, comment 9: In the Discussion section, the 4.2 and 4.3 subsections are not a scientific discussion of the data. The authors must use this section to explain the behaviour of the results and/or compare their results with other published research.

Response: We are very grateful to the reviewer for the comment, and we agree with the suggestion.

For 4.2 in the Discussion section, we rewrite this part to highlight the differences between the improvement method of this research and other methods, namely,

“4.2 The comparison comes from the improved method in this study and the conventional method

This study not only provides new research results in land change and landscape pattern, but also provides the improved method of ecosystem service value in Northeast China. In previous relevant studies, the conventional method usually chooses to ignore the ecosystem service value of construction land (i.e., set as 0 value) and rely on the change of the ecological value of dominant land cover, such as the ecosystem value evaluation of Sanjiang Plain in Northeast China [61]. Also, some other scholars also ig-nore this problem [62,63]. In the previous literature, construction land [61], including urban, rural land, and industrial and mining land, is always treated as bare land, which often leads to the underestimation of the ecosystem service value in Northeast China. In the contexts of large-scale construction land expansion, ecological elastic cities, livable cities and rural revitalization policies [64,65] have helped to increase the vegetation within the construction land area. Also, the impact of construction land on regional eco-logical functions such as purified environment, biodiversity and aesthetic landscape, needs the ecosystem value assessment. Therefore, by investigating the land cover dis-tributions within construction land in Northeast China, we provide a new ecosystem service value calculation of construction land. In the actual survey, the impervious sur-face land of the construction land is about two-thirds, the other one-third consists of the equal woodland and grassland, and the water body can be basically ignored [66]. There-fore, from the perspective of land cover, we put forward a new method to calculate the ecosystem service value of construction land in Northeast China, that is, the calculation of construction land is 4/6 bare soil (impervious surface land) + 1/6 grassland + 1/6 forest land. This means that we consider the vegetation factors inside the construction land, to make the ecosystem assessment more accurate. In addition to the comparison between the method in this study and traditional method, we also conduct the comparative ex-periments in the study area according to these two methods. We find that: the total eco-system service value in Northeast China was 2,774.99 billion yuan, 2,725.57 billion yuan and 2,702.96 billion yuan in 2000, 2010 and 2020 from conventional method, respectively, while our method obtain more ecosystem service, with more values of 93.39 billion yuan, 98.59 billion yuan and 111.10 billion yuan in 2000, 2010 and 2020. Therefore, our research can obtain more accurate results compare to traditional method in Northeast China”. (page 14, lines 417-447, in the revised manuscript).

 

For 4.3 in the Discussion section, we have made extensive modifications to improve its quality. The contents are displayed below: “According to the land dynamic change, this paper studies the landscape pattern and ecosystem service value in the period of 2000-2020 in Northeast China. We provide the new results on land change and landscape pattern and create an improved ecosystem service value assessment method to provide the more suitable ecosystem assessment application for Northeast China. However, the monetary values are displayed in Chinese yuan. Maybe, the monetary values in USD increase the visibility of the paper. Considering the fluctuation and uncertainty of RMB and US dollar exchange rate from 2000 to 2020 [67], this study use the Chinese yuan. And we will overcome the exchange rate problem between RMB and US dollar in future research and unify it into US dollar. Furthermore, we focus on the impact of land transition on landscape and ecosystem service value in northeast region of China from 2000-2020. Land use change also brings biogeo-chemical and biogeochemical cycle processes such as surface hydrological process, groundwater change, evapotranspiration [68], surface radiation energy balance [69], car-bon cycle and local climate change [60]. We will conduct more extensive research in the future”. (page 15, lines 455-469, in the revised manuscript).

 

Reviewer# 5, comment 10: Specific comments

Response: We thank the reviewer for the comments and reply the comments by point-to-point below.

 

Reviewer# 5, comment 11: Line 52: It is not clear what “focused environmental issues” means.

Response: We are very sorry that the description of the original manuscript is not clear. To make the description clear, we revise it below, namely, “It also provides ecosystem service for the focused issues such as climate warming 52 [17], carbon cycle [18] and hydrological process [19]”. (page 2, lines 50-52, in the revised manuscript).

 

Reviewer# 5, comment 12: Line 58: It is not clear what “make the evaluation accuracy of land use need to be improved” means.

Response: We are very sorry that the description of the original manuscript is not clear. To make the description clear, we revise it below, namely, “Relatively coarse resolution of early land products, such as 1 km MODIS [25] and 300 m European Space Agency (ESA) land cover data in the period of 1992-2015 [26] may not be accurate enough for the evaluation of regional scale land area”. (page 2, lines 55-57, in the revised manuscript).

 

Reviewer# 5, comment 13: Lines 61-66: The authors should also show what is the spatial resolution of this dataset, so readers can compare it with the previously mentioned ones.

Response: We are very sorry that the description of the original manuscript is not clear. The format of this dataset is vector. We add this information to the revised manuscript, so that the readers can compare it with the previously mentioned ones. (page 2, line 62 in the revised manuscript).

 

Reviewer# 5, comment 14: Line 68: I do not see why the used software should be mentioned in the Introduction section.

Response: We agree with the reviewer's suggestion. The description of the software information is deleted considering that such a description is redundant.

 

Reviewer# 5, comment 15: Lines 71-72: There is no explanation of the importance of given value to nature, this is an important part of the research, so the authors have to better address this topic.

Response: We are very grateful to the reviewer for the comment and we agree with the suggestion. The importance of given value to nature is added in the revised manuscript, namely, “The change of ecosystem service value is beneficial for the assessment of natural environment quality such as the cultural service (i.e., spiritual, entertainment and cultural benefits) and support service (i.e., maintaining the nutrient cycle of the earth's living environment). Therefore, this study provides the more suitable ecosystem assessment utility for Northeast China”. (pages 15-16, lines 505-509, in the revised manuscript).

 

Reviewer# 5, comment 16: Line 76: It is not clear what “we localized and revised” means.

Response: We are very sorry that the description of the original manuscript is not clear. To make the description clear, we revise it below, namely, “In view of the deficiency that the construction land is regarded as bare land in this method, we improve a new calculation method, to present the more real ecosystem service as well as its change”. (page 2, lines 84-86, in the revised manuscript).

 

Reviewer# 5, comment 17: Line 84: What is still lacking?

Response: We are very sorry that the description of the original manuscript is not clear. To make the description clear, we revise it below, namely, “the latest land change and its impact on landscape and ecosystem service value in Northeast China are still lacking”. (page 2, lines 96-97, in the revised manuscript).

 

Reviewer# 5, comment 18: Line 85: It is not clear what “law” means.

Response: We are very sorry that the description is not clear. To make the description clear, the word “law” is replaced by “spatial pattern”. (page 2, line 98, in the revised manuscript).

 

Reviewer# 5, comment 19: Line 86: If the dataset was produced by another institution, how do you provide a “new land-use change phenomenon”? And I believe that you mean “describe” instead of “provide”, right?

Response: We thank the reviewer for the suggestion. We add more detailed information in this section of the revised manuscript, namely,

“Among them, the land use dataset comes from the data center of resources and environment, science of the Chinese Academy of Sciences. And we are the member of data production that the data is first used (i.e., the land use data in the year 2020)”. (page 4, lines 142-145, in the revised manuscript).

Also, we agree with the reviewer' comment. The word “describe” is better than “provide”, and we use the word “describe” in the revised manuscript. (page 2, line 100, in the revised manuscript).

 

Reviewer# 5, comment 20: Line 102 and forward: The authors mentioned a statistic, so these statistics must be referenced.

Response: We thank the reviewer for the suggestion, and the reference is added in the revised manuscript. (page 3, line 116, in the revised manuscript).

 

Reviewer# 5, comment 21: Line 109: What are the “one core and five strategies”?

Response: We are very sorry that the description is not clear, to make the description clear, we revise it below, namely, “one core (i.e., economic center) and five strategies (i.e., grain, manufacturing, ecology, people's livelihood, enterprise development)”. (page 3, lines 123-125, in the revised manuscript).

 

Reviewer# 5, comment 22: Figure 1: The boundaries shown in Figure 6 should also be given here since you studied each of these locations.

Response: We thank the reviewer for the suggestion. We add the boundaries shown in Figure 6 to the Figure 1 in the revised manuscript. (page 3, line 128-129, in the revised manuscript).

 

Reviewer# 5, comment 23: Line 140: I do not think that you should use a word such as “always” in scientific research.

Response: We are very grateful to the reviewer for the comment, and we agree with the suggestion. The word “always” is deleted in the revised manuscript.

 

Reviewer# 5, comment 24: Table 1: You must reference the literature from where you extracted each of these formulas. And describe the meaning of each variable.

Response: We are very grateful to the reviewer for the comment, and we agree with the suggestion. These formulas are all from user guide document, and we add the reference in the revised manuscript. Also, the describe the meaning of each variable is added. (page 5, lines 185-186, in the revised manuscript).

 

Reviewer# 5, comment 25: Line 171: Reference the “relevant research” mentioned.

Response: We are very sorry that this description is redundant, and we delete it in the revised manuscript.

 

Reviewer# 5, comment 26: Table 3: What is the monetary unit used? Give values also in USD or at least the conversion rate at the time of publication of the paper.

Response: We are very grateful to the reviewer for the comment, and we agree with the suggestion. To make this clear, we add the monetary unit to the title of Table 3, namely, “Table.3 Coefficient tables of ecosystem service value in the study area (Unit: Chinese yuan (RMB))”. (page 6, line 220, in the revised manuscript).

 

Reviewer# 5, comment 27: Figure 3: What is the unit on the left axis? What does “law” mean here?

Response: We are very sorry that the description is not clear, to make the description clear, we revise it below, namely, “Figure.3 Landscape change trend in landscape level during the period of 2000-2020. Note: The left axis is a dimensionless unit”. (page 10, lines 300-301, in the revised manuscript).

 

Reviewer# 5, comment 28: Lines 270-274: Sound like a discussion of the results.

Response: We are very grateful to the reviewer for the comment, and we agree with the suggestion. The lines 270-274 are deleted in the revised manuscript, because this description is not suitable in the result section.

 

Reviewer# 5, comment 29: Lines 300-303: Sound like methodology.

Response: We are very grateful to the reviewer for the comment, and we agree with the suggestion. The lines 300-303 are deleted in the revised manuscript, because this description is not suitable in the result section.

 

Reviewer# 5, comment 30: Figure 5: What is the unit on the left axis?

Response: We are very sorry that the description is not clear, to make the description clear, we revise it below, namely, “Figure.5 value changes of ecosystem services during 2000-2020. Note: Unit on the left axis 10⁸ yuan”. (page 12, line 368, in the revised manuscript).

 

Reviewer# 5, comment 31: Lines 331-335: Should be in the Methodology section. It is also difficult to track the numbers I, II, III, IV and V throughout the text. It would be easier to read if you use acronyms for each level. Also, in the Methodology section, it must be presented what each of these levels means.

Response: We are very grateful to the reviewer for the comment and we agree with the suggestion. The lines 331-335 are moved to method section. In the methodology section, we add what each of these levels means. (page 8, lines 243-248, in the revised manuscript).

To easily track numbers in Figure 6, we add the means of each level in the title section. (page 13, lines 388-391, in the revised manuscript).

 

Reviewer# 5, comment 32: Lines 340- 353: I suggest that this discrimination per District could be turned into a table, where the authors could also give the mean results per District.

Response: We are very grateful to the reviewer for the comment. A table is added (i.e., Table 5) to the discrimination per district in the revised manuscript. (page 13, lines 393-394, in the revised manuscript).

 

Reviewer# 5, comment 33: Discussion section: The titles of the subsection are not clear.

Response: We are very sorry that the description is not clear, to make the description clear, we revise the titles of the subsection below:

 

4.1 The reduction of cultivated land area is revealed in Northeast China (page 13, line 395, in the revised manuscript).

 

4.2 The comparison comes from the improved method in this study and the conventional method (page 14, line 417, in the revised manuscript).

 

4.3The shortcomings of this study and the plan for the next step (page 14, line 448, in the revised manuscript).

 

Reviewer# 5, comment 34: Line 361 and 363: It is not clear what “land reclamation” means.

Response:

Response: We are very sorry that the description is not clear, to make the description clear, we revise the words “land reclamation” to “land area” in the revised manuscript.

 

Reviewer# 5, comment 35: Subsection 4.2: It is entirely written as results – no discussion is made.

Response: We are very grateful to the reviewer for the comment, and we agree with the suggestion. The subsection 4.2 is completely deleted in the revised manuscript. And we add a new discussion 4.2 below:

“4.2 The comparison comes from the improved method in this study and the conventional method

This study not only provides new research results in land change and landscape pattern, but also improves the evaluation method of ecosystem service value in Northeast China. In previous relevant studies, the conventional method usually chooses to ignore the ecosystem service value of construction land (i.e., set as 0 value) and rely on the change of the ecological value of dominant land cover, such as the ecosystem value evaluation of Sanjiang Plain in Northeast China [62]. Also, some other scholars also ignore this problem [63,64]. In the previous literature, construction land [62], including urban, rural land, and industrial and mining land, is always treated as bare land, which often leads to the underestimation of the ecosystem service value in Northeast China. In the contexts of large-scale construction land expansion, ecological elastic cities, livable cities and rural revitalization policies [65,66] have helped to increase the vegetation in the construction land area. Also, the impact of construction land on regional ecological functions such as purified environment, biodiversity and aesthetic landscape, needs the ecosystem value assessment. Therefore, by investigating the land cover distributions within construction land in Northeast China, we provide a new ecosystem service value calculation of construction land. In the actual survey, the impervious surface land of the construction land is about two-thirds, the other one-third consists of the equal woodland and grassland, and the water body can be basically ignored [67]. Therefore, from the perspective of land cover, we put forward a new method to calculate the ecosystem service value of construction land in Northeast China, that is, the calculation of construction land is 4/6 bare soil (impervious surface land) + 1/6 grassland + 1/6 forest land. This means that we consider the vegetation factors inside the construction land, to make the ecosystem assessment more accurate. In addition to the comparison between the method in this study and traditional method, we also conduct the comparative experiments on the study area according to these two methods. We find that: the total ecosystem service value in Northeast China was 2,774.99 billion yuan, 2,725.57 billion yuan and 2,702.96 billion yuan in 2000, 2010 and 2020 from conventional method, respectively, while our method obtain more ecosystem service with values of 93.39 billion yuan, 98.59 billion yuan and 111.10 billion yuan in 2000, 2010 and 2020. Therefore, our research can obtain more accurate results compare to traditional method in Northeast China”. (page 14, lines 417-447, in the revised manuscript).

We are very grateful to the reviewer for the comments, which have constructively improved the quality of the manuscript.

 

Author Response File: Author Response.pdf

Round 2

Reviewer 3 Report

The efforts made by the Authors are apprecciated.

Reviewer 4 Report

I have no other comments.

Reviewer 5 Report

The authors properly answered the points made and improved the overall quality of the paper. All sections are clearer and more focused after the review.