Improving Ecosystem Services Production Efficiency by Optimizing Resource Allocation in 130 Cities of the Yangtze River Economic Belt, China
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThe manuscript's authors, “Improving ecosystem services production efficiency by optimizing
resource allocation in 130 cities of the Yangtze River Economic Belt, China”, presented and examined the
they study first employed the InVEST models to clarify spatio-temporal changes in five key ESs. The static
and dynamic efficiency of ESs production from 2015 to 2021 of 130 cities in the Yangtze River Economic
Belt (YREB) they were then measured by employing the super SBM-Malmquist model with regarding ESs
as outputs. The authors have shown the following results indicated that water conservation (WC), water
purification (WP) and soil retention (SR) presented an overall decline trend, decreasing by 28.32%, 3.22%
and 10.00%, respectively, while carbon storage (CS) and habitat quality (HQ) remained steady. As a result
of the study, the authors point out that more than 70% of studied cities exhibited static efficiency levels
below 50%, which can be attributed to excessive input redundancy.
In the introduction, the authors provide a literature review on the current state of the Yangtze River
ecosystem. In this review, the authors note that the river ecosystem has suffered greatly due to
overexploitation. At the same time, the authors point out that the Chinese government is now using large
investments to restore this ecosystem. This review is quite professional in its search for the essence of the
problem and uses modern sources that are relevant to the topic of the study.
In Section 2, the authors present the methods and materials they used to conduct their research. In
this section, they provide a brief introduction to the study area near the Yangtze River, as well as the various
ecosystem service assessments that are being conducted to restore the ecosystem. Also in this section, they
use a quantitative assessment of ecosystem service production efficiency, and two measurement models are
used for this purpose: the Super Slacks-based measurement model and the Malmquist index model. The
results described in this section are reliable and adequate.
The third section of this study is devoted to the results and their analysis. The results obtained by the
authors in this section are adequate and meet the objectives of their research.
Though authors follow the Sustainability journal guidelines and form the paper structure properly,
there are several aspects that should be improved:
1. It is advisable to zoom in on the left side of Figure 2.
2. If possible, please improve the bone of the image in Figure 4
Comments for author File: 
Comments.pdf
Author Response
We sincerely appreciate your insightful suggestions. Given the substantial modifications made throughout the manuscript, we have summarized the specific revisions in the attached document for your review.
Author Response File: 
Author Response.docx
Reviewer 2 Report
Comments and Suggestions for AuthorsDear authors,
The paper presents an engaging and valuable contribution to the field of ecological restoration. The methodological approach is well structured and rigorous. The case study provides a concrete example of the significance of knowledge produced and the consequent policy implications for optimising ecosystem services production efficiency.
Here are some suggestions to improve your work:
The Introduction section is somewhat redundant, so I suggest revising the language form in the first paragraph (35-38 and again 38-44).
It would be interesting to refer in lines 37-38 to some examples of policies for ecological restoration (which ones are you talking about? What are they about? Are they specific to certain ecosystem topologies?). There seems to be a missing link with the following sentence where the river is mentioned (line 38), so perhaps some examples related to river ecosystems would be useful.
Line 57, there is a wording error in the sentence (‘while’ is not accompanied by a second sentence with which to be compared).
Between lines 61 and 62, it would be helpful to add a sentence to clarify the model, as it becomes complicated for those unfamiliar with it to understand the following sentence (lines 62-65).
Line 75, please give a definition to the SBM-Malmquist model. You rightly give one on line 137, but I think it would be clearer to have it earlier.
In the description of Figure 1, I would perhaps spend a few words on ‘desirable’ and ‘undesirable’ outputs. It is the only part of the picture whose meaning is not directly understood. Even in section 2.3, where these terms are mentioned, it is not explained what they refer to, nor is it explained why WP is undesired. Instead, I think it is significant to state your interpretation.
In section 3.1 (for example, lines 182-183), you mention the distribution in different areas that are indicated in Figure 2 of the case study section. However, the map on the left side of Figure 2 is too small and difficult to read, thus making it difficult to interpret the spatial distribution you refer to. I suggest enlarging Figure 2 to the edge of the page or modifying the map on the left, e.g. keeping only the outline of the study area and then removing the polygon fill and the river. The comment also applies to section 3.2.3, which is difficult to read without a clear map in support.
Line 212, you mention Figure 5, but it is Figure 4. The same happens in line 215.
The graph in Figure 4 (d) is very small and would benefit from being enlarged. A possible alternative would be to put the three maps vertically on the left and transpose the graph vertically on the right.
Line 340, maybe the word ‘supply’ is missing after ‘ecosystem service’?
Thank you for your interesting contribution!
Author Response
We sincerely appreciate your insightful suggestions. Given the substantial modifications made throughout the manuscript, we have summarized the specific revisions in the attached document for your review.
Author Response File: Author Response.docx
Reviewer 3 Report
Comments and Suggestions for AuthorsPeer Review – Comments for Authors
- Line 15–22 (Abstract):
The abstract clearly outlines the research aims, methods used, as well as what it discovered; yet, the wording can be improved for clarity. For example, "the efficiency of these ambitious practices remains unclear" (line 14–15) lacks concreteness. This can cause some readers to wonder: “Which practices?” or “Efficiency in what sense?”
Recommendations
It would be helpful to define that these guidelines apply for wide-spread ecological restorations across the YREB. Also, it would be more appropriate to rescript cumbersome terms like "excessive input redundancy" (line 23), which can be refashioned as “inefficient utilization of resources, including labor, capital, and technology.”
- Line 36–48 (Introduction):
The phrase “local governments falsify the plan of the programme…”(line 47) shows both grammatical error as well as obscurity.
Recommendations
Some of the municipal authorities have been blamed for exaggerating their rehabilitation initiatives in a bid to obtain more ecological compensation funds, thus being guilty of misusing those funds. This can be proven with proper citation or government records, as necessary.
- Lines 55–64 (
The paragraph introduces the DEA method and limitations of traditional models. While informative, it uses technical language without transition.
Proposal
To help readers unfamiliar with DEA, briefly introduce what decision-making units (DMUs) are and explain why slack variables matter in performance analysis. A short example of how slack leads to inefficiency could enhance clarity.
- Lines 74–84 (Conclusion of Introduction):
The explanation of the research approach is informative; however, the phrase "ESs are incorporated into evaluation design as a representational signal of stocks of ecological resources" (lines 75–76) sounds unclear and very abstract.
Recommendations
Therefore, ecosystem services act as measurable indicators of the ecological benefits resulting from conservation efforts, enabling evaluation of efficiency of inputs—human labor and funds—against outputs, for example, rainfall retention as well as sequestration of stored carbon, thus enabling more informed decision-making.
- Line 103–110 (Section 2.2):
The table outlining some ecosystem services shows informative content; however, its Water Purification (WP) account shows inconsistencies. While it shows a heightened nitrogen delivery as an index of diminished functionality (a hypothesis that might be met with some agreement), it doesn't specifically list WP as a collateral action.
Proposal
We must be clear in both the table provided and the writing that WP, measured in terms of N-output, is treated inversely−as a negative output in the efficiency function.
- Lines 122–135 (Super SBM Framework
The next section gives a mathematical description of the model. Although it is accurate, it doesn't provide an explanation about the practical meaning of slack variables adequate for a reader without expert knowledge.
Recommendations
The slack variables refer to a surplus of inputs or a decrease in outputs. For instance, if a municipality uses more labor than needed for soil retention, a model recognizes this condition as characteristic of a surplus of labors.
- Lines 169 to 198 (Section 3.1 –
The distributional pattern of WC, WP, SR, CS, and HQ is informative, though explanations sometimes prove difficult to understand because of long sentences as well as varying terms.
Recommendations
Split long paragraphs. Use consistent units (e.g., "t/ha" vs. "t ha−1") and include a sentence summarizing key takeaways, such as: “The consistent decline in water conservation and soil retention suggests that restoration efforts may not be offsetting degradation trends in urban and lowland areas.”
Section 8: Lines 203–230 (Static Efficiency
The usage of efficiency values over 100% (e.g., 192.91%) is algebraically permissible for Super SBM models, although it calls for a more accurate interpretation.
Recommendations
Efficiencies of more than 100% reflect truly outstanding locations of cities, with those locations delivering a high amount of ecosystem services using comparatively low resource inputs.
- Sections 235–276 (Redundancy Assessment
The discussion of redundancy is insightful but the section is dense, with city names and percentages listed continuously.
Recommendations
Use a heat map or tabular summary from supplementary material to explain these values more clearly. Then summarize the observed patterns—like, “The cities that experienced a change from low to high redundancy were mostly located in the eastern region, suggesting a probable increase in inefficiencies.”
- Sections 296–331 (Dynamic Efficiency
The Malmquist decomposition was done accurately; however, there is a need to consider potential data artifacts or lagged ecosystem responses within the recovery phase from 2018 to 2021.
Recommendations
We should acknowledge a possible lag between activating restoration efforts and registering change in ecosystem service indicators. Such rebound can be a partial indication of slow ecosystem responses to inputs from restoration, not gains in immediate efficiency.
- Lines 337–365 (
The research points out spatial distribution differences but pays great stress on vegetation significance; meanwhile, no link is made in its research outcomes with current environmental policies of China, like the ecological redline strategy. Recommendation The inclusion of details related to certain policies or recent planning papers helps illustrate potential applications of this research in concrete policy regimes. Such inclusion makes the discourse more applicable. 12. Extract 412–430 ( The restrictions section is honest as well as informative. However, some aspects—like the scale limitation of the InVEST model—are discussed only briefly. Recommendations Expand this part to reflect the model's sensitivity to parameterization and land cover input quality. Consider stating: “While InVEST offers accessibility and transparency, it does not fully capture process-based feedbacks, such as nutrient cycling or biodiversity thresholds.” 13. Lines 431–447 ( The abstract is concise but shows some redundancy. It repeats the conclusions without mentioning the wider implications of the research. Recommendation The paper offers an efficiency-focused approach that holds great potential for enabling adaptive, place-responsive ecosystem governance in increasingly fast-moving city centers worldwide. Conclusionary Statements This paper makes an important contribution to the literature and is well structured, posing fundamental ecological questions with quantitative clarity. The research fills an important gap in understanding about effects of investment and resource distribution on ecosystem service delivery efficiency across broad-scaled urban-rural gradients. Through improving clarity of expression, giving a better rationale for chosen indicators, and entering more contextual discourse, this paper stands ready to provide a relevant addition to sustainability as well as ecological economics literature. Please let me know if you would like the same structure and detail for editor comments, or formatted feedback for submission.
Author Response
We sincerely appreciate your insightful suggestions. Given the substantial modifications made throughout the manuscript, we have summarized the specific revisions in the attached document for your review.
Author Response File: Author Response.docx
