Organic Fertilizer Effects on Ecosystem Multifunctionality and Trade-Offs in Alpine Mine Reclamation

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

 This manuscript focuses on the challenging issue of ecological restoration in high-altitude mining areas with fragile ecosystems, specifically evaluating the effectiveness of organic fertilizers as a practical improvement measure. It has direct reference value for ecological engineering practices in high-altitude regions. Five treatments were adopted, including no-fertilizer control (CK), low (LF), medium (MF), and high (HF) fertilizer gradients, as well as natural grassland (NM) control, with repetitions set up. The sampling and analysis methods were standardized, and the data support was solid. An ecosystem multifunctionality evaluation system was constructed, including five major functional groups: primary productivity, water source conservation, carbon cycle, nitrogen cycle, and phosphorus cycle, with 26 specific indicators, avoiding the limitations of single-index evaluation. The root mean square deviation (RMSD) method was used to quantitatively analyze the trade-off intensity among ecosystem functions, revealing that the artificial restoration area is more inclined towards productivity and nutrient cycling, while the natural grassland has a prominent water source conservation function. This study is a well-designed and data-rich empirical research on ecological restoration. Some suggestions are as follows.

1. There are some grammatical and spelling errors throughout the text. For instance, in line 332, it should be "mining" instead of "minging"; in Table 1, it should be "gkg^-1" instead of the incorrect form. Line 41-42, "The Jiangcang mining area, situated in the core zone of the Muli coalfield within the southern foothills of the Qilian Mountains, exemplifies a typical alpine mining, characterized by high elevation..."  line 247-248,"... significantly exceeded those of the natural meadow..."
2. When presenting specific data, avoid simply listing them; instead, highlight the most significant differences and change patterns among different treatments.
3. The exploration of the mechanism behind the interesting phenomenon of why organic fertilizer amendment has enhanced the trade-offs among functions could be further delved into. The limitations of the study itself (such as the single sampling time point, the lack of dynamic process data, and the failure to distinguish between soil particulate organic carbon and mineral-bound organic carbon, etc.) are not adequately explained.
4. Why is the soil microbial biomass pathway not significant? This might imply that in the short-term improvement, the response of microorganisms is still unstable or there is a lag effect.
5. In Section 3.3 and Table 3, the trade-off intensity between "water conservation vs. phosphorus cycling" under the NM treatment (ERMSD = 0.50) is much higher than that of other combinations. The reason for this extreme value deserves in-depth analysis in the discussion (such as whether it is due to the extremely high water conservation function and relatively low phosphorus cycling function of NM).

Comments on the Quality of English Language

The English could be improved to more clearly express the research.

Author Response

Comments 1: There are some grammatical and spelling errors throughout the text. For instance, in line 332, it should be "mining" instead of "minging"; in Table 1, it should be "gkg-1" instead of the incorrect form. Line 41-42, "The Jiangcang mining area, situated in the core zone of the Muli coalfield within the southern foothills of the Qilian Mountains, exemplifies a typical alpine mining, characterized by high elevation..."  line 247-248,"... significantly exceeded those of the natural meadow..."

Response 1: Agree, We have checked and corrected the grammatical and spelling errors in the text. We have marked the values significantly higher than those of natural grasslands from line 275 to 276 and annotated them in red.

 

Comments 2: When presenting specific data, avoid simply listing them; instead, highlight the most significant differences and change patterns among different treatments.

Response 2: Agree, We have supplemented the differences and trends between different treatments in the results analysis section.

 

Comments 3: The exploration of the mechanism behind the interesting phenomenon of why organic fertilizer amendment has enhanced the trade-offs among functions could be further delved into. The limitations of the study itself (such as the single sampling time point, the lack of dynamic process data, and the failure to distinguish between soil particulate organic carbon and mineral-bound organic carbon, etc.) are not adequately explained.

Response 3: Agree, We have explained this phenomenon in detail from line 489 to 498.

 

Comments 4: Why is the soil microbial biomass pathway not significant? This might imply that in the short-term improvement, the response of microorganisms is still unstable or there is a lag effect..

Response 4: Agree, We have explained in detail the reasons for this result from line 407 to line 415.

 

Comments 5: .In Section 3.3 and Table 3, the trade-off intensity between "water conservation vs. phosphorus cycling" under the NM treatment (ERMSD = 0.50) is much higher than that of other combinations. The reason for this extreme value deserves in-depth analysis in the discussion (such as whether it is due to the extremely high water conservation function and relatively low phosphorus cycling function of NM)..

Response 5: Agree, We have deeply analyzed the reasons for the strong balance between water source conservation and phosphorus cycle from line 531 to 542.

Reviewer 2 Report

Comments and Suggestions for Authors

This manuscript presents a timely and scientifically robust investigation into the impacts of organic fertilizer-based reclamation on ecosystem multifunctionality (EMF) and functional trade-offs in an alpine mining context on the Tibetan Plateau. The study fills an important knowledge gap, as most prior research on EMF has focused on forests or temperate grasslands, with limited attention to high-altitude, post-mining ecosystems. The experimental design is sound, the methodology is well-described and appropriate, and the findings are clearly articulated with strong implications for sustainable restoration practices in fragile alpine environments.

The conclusions are generally well-supported by the data, and the use of both single-function and averaged EMF metrics, along with RMSD based trade off analysis, adds methodological rigor. However, several revisions are recommended to enhance clarity, scientific depth, and alignment with Land’s publication standards.

1. Clarify the Novelty and Contextual Relevance for Land

While the study is technically strong, the Introduction could better emphasize why this work matters specifically for land system science and policy. Land prioritizes research with implications for land governance, restoration planning, and sustainable land management. The authors should explicitly link their findings to:

• Practical guidelines for land reclamation in high-altitude mining regions.
• Trade-off-aware restoration planning (e.g., balancing productivity vs. water conservation).
• Policy recommendations for organic amendment use in fragile ecosystems.

Suggested revision: Expand the final paragraph of the Introduction to articulate how this study informs land-use decision-making in post-mining landscapes under climate and ecological stress.

2. Strengthen the Discussion on Trade-offs vs. Synergies

The paper consistently refers to “trade-offs,” but the RMSD metric alone doesn’t distinguish true trade-offs (one function increases while another decreases) from asynchronous improvements (both functions increase, but unequally). The manuscript should clarify this conceptual limitation.

Suggested revision:

• Define “trade-off” more precisely in Section 2.5.
• Consider adding a brief analysis or statement on whether any synergies (simultaneous increases) were observed (e.g., between C and N cycling).
• Discuss whether RMSD values reflect genuine ecological competition or simply differential responsiveness to fertilization.

3. Address the Paradox of Higher EMF in HF vs. Native Meadow

The finding that the high-fertilizer (HF) treatment exceeds native meadow (NM) in EMF (0.69 vs. 0.60) is striking but potentially misleading if NM excels in critical regulating functions like water conservation (which it does). The authors rightly note this, but the implications for ecosystem resilience and long-term sustainability need deeper discussion.

Suggested revision:

• Emphasize that EMF is an aggregate index and may mask critical functional imbalances.
• Discuss whether a system with high productivity but low water retention is desirable or stable in water-limited alpine regions.
• Recommend function-weighted EMF approaches or minimum threshold criteria for land restoration goals.

4. Clarify Fertilizer Composition and Application Protocol

• Table 1 lists properties of inputs, but it’s unclear whether sheep manure and commercial fertilizer were applied simultaneously or as a mixture. Clarify.
• Was pH or salinity of amendments measured? These can affect plant establishment in sensitive alpine soils.

5. Statistical Reporting

• The manuscript states “ANOVA followed by Duncan test (p < 0.05),” but Duncan’s test is less common in ecological literature due to inflated Type I error. Consider justifying its use or switching to Tukey’s HSD or Benjamini–Hochberg correction if multiple comparisons are a concern.

6. Figures and Data Presentation

• Figure 6 (scatter plots of trade-offs) would benefit from regression lines or confidence ellipses to visualize relationships.
• In Table 3, include sample size (n = 6) in the caption for clarity.

7. Language and Formatting

• Minor grammatical errors and spacing issues (e.g., “regu lating,” “p ro p erties”) should be corrected.
• Ensure all acronyms (e.g., MWHC, CWC, ALP) are defined at first use.

Comments on the Quality of English Language

The manuscript is generally well-written and the scientific content is clearly conveyed. However, the English language requires moderate improvement to meet the publication standards of Land. Several sections contain typographical errors (e.g., “regu lating”, “p ro p erties”, “Acce p ted”), inconsistent spacing, and minor grammatical issues that affect readability. Additionally, some technical sentences particularly in the Introduction and Discussion could be rephrased for greater clarity and fluency.

It is recommended that the manuscript undergo professional English editing or thorough proofreading by a native or proficient English speaker before final acceptance. This will ensure precise expression of scientific concepts and enhance the overall readability of the paper.

Author Response

Comments 1: Expand the final paragraph of the Introduction to articulate how this study informs land-use decision-making in post-mining landscapes under climate and ecological stress.

Response 1: Agree, We have expanded the introduction section from line 105 to 115 to clarify the practical significance of this study, and proposed follow-up management suggestions for alpine mining areas in the discussion section from line 464 to 471.

Comments 2: Define “trade-off” more precisely in Section 2.5. Consider adding a brief analysis or statement on whether any synergies (simultaneous increases) were observed (e.g., between C and N cycling). Discuss whether RMSD values reflect genuine ecological competition or simply differential responsiveness to fertilization.

Response 2: Agree, We have precisely defined the concept of trade-off in Section 2.5 (lines 222 to 233).

This study mainly focuses on analyzing the trade-off relationships between ecological functions, with collaboration not being analyzed and explained in detail. However, there is also a phenomenon of weakened trade-off degree between pairwise ecological functions in this study. Therefore, we added a description of the decreased trade-off relationship between ecological functions at lines 340 and 345.

 

Comments 3: Emphasize that EMF is an aggregate index and may mask critical functional imbalances.

Discuss whether a system with high productivity but low water retention is desirable or stable in water-limited alpine regions. Recommend function-weighted EMF approaches or minimum threshold criteria for land restoration goals.

Response 3: Agree, We have elaborated on the limitations of the EMF indicator and the sustainability of ecosystems with high productivity and low water conservation function from line 456 to 471 in the discussion section, and proposed further management suggestions. In addition, although we use the ecosystem multifunctionality (EMF) value of natural grasslands as the theoretical maximum threshold in this study, given the significant gap between the reclaimed ecosystem and natural grasslands in terms of function and structure, this threshold needs to be used with caution in practice. Specifically, it is mainly applicable to the reclaimed ecosystem scenario of mining areas based on long-term observations, and it must be used in conjunction with multivariate analysis and a multi-dimensional evaluation framework.

 

Comments 4: Clarify Fertilizer Composition and Application Protocol Table 1 lists properties of inputs, but it’s unclear whether sheep manure and commercial fertilizer were applied simultaneously or as a mixture. Clarify. Was pH or salinity of amendments measured? These can affect plant establishment in sensitive alpine soils.

Response 4: Agree, We have described the mixed application of nutrient and commercial organic fertilizer from line 135 to line 135. Table 1 has supplemented the pH values of coal gangue, sheep manure, and commercial organic fertilizer.

 

Comments 5: The manuscript states “ANOVA followed by Duncan test (p < 0.05),” but Duncan’s test is less common in ecological literature due to inflated Type I error. Consider justifying its use or switching to Tukey’s HSD or Benjamini–Hochberg correction if multiple comparisons are a concern.s and Data Presentation

Response 5: We thank the reviewer for this valid comment. While we agree that Tukey's HSD provides stricter control over Type I errors, we opted for Duncan’s Multiple Range Test as it is widely accepted and frequently used in studies related to [insert field, e.g., plant ecology / agronomy / soil remediation] for separating means when multiple treatments are involved. Using Duncan’s Multiple Range Test allows our results to be directly comparable with previous literature in this specific domain (We have introduced literature on the ecological aspect using the Duncan test method in the analysis method section.), where this method is standard for ranking treatment efficacy. We have ensured that the global ANOVA was significant before applying the post-hoc test to maintain statistical rigor. We hope this justification is acceptable.

 

Comments 6: Figure 6 (scatter plots of trade-offs) would benefit from regression lines or confidence ellipses to visualize relationships. In Table 3, include sample size (n = 6) in the caption for clarity.

Response 6: Agree, We have marked the sample size in Table 3. In addition, trade-off scatter plots characterize the trade-off relationships between ecosystem services by measuring the distance from a given ecosystem service coordinate point to the trade-off parallel line. The relative position of data points to the trade-off parallel line also indicates which ecosystem service yields greater benefits under a specific scenario. Therefore, other charts cannot currently replace trade-off scatter plots for this representation.

 

Comments 7: It is recommended that the manuscript undergo professional English editing or thorough proofreading by a native or proficient English speaker before final acceptance. This will ensure precise expression of scientific concepts and enhance the overall readability of the paper.

Response 7: Agree, We have used professional language editors to proofread the article and ensured that the language of the article complies with the Land journal.

 

Reviewer 3 Report

Comments and Suggestions for Authors

good efforts

Comments for author File: Comments.pdf

Author Response

Comments 1: The title is relatively complex; please simplify it further.

Response 1: Agree, We have changed the article title to “Organic Fertilizer Effects on Ecosystem Multifunctionality and Trade-offs in Alpine Mine Reclamation”.

 

Comments 2: In line 12 " unfertilized control, low fertilizer, medium fertilizer, and high fertilizer, with natural grassland serving as the control" do you have 2 control treatments ? These details must be explained precisely.

Response 2: Agree, We have described the experimental design in detail in the introduction and the materials and methods section(Line 8-12, Line 141-143).

 

Comments 3: In line 17 " The root mean square deviation (RMSD) method was employed to nalyze trade-offs among functions " It is preferable to write it in the Materials ection only.

Response 3: Agree, We have deleted the method of “The root mean square deviation (RMSD)” in the abstract part.

 

Comments 4: In line 27 " You can write a more in-depth future vision for this research work.

Response 4: Agree, We have added a more in-depth future vision for this research work in line 25-30.

 

Comments 5: At the end of the introduction, write the sustainable development goals that your esearch helps to achieve.

Response 5: Agree, We have expanded the sustainable development goals that this research contributes to achieving in line 105-115.

 

Comments 6: Lines from 130 to 133 should be written in the abstract.

Response 6: Agree, We have already included this part of the content in lines 8 to 12 of the abstract.

 

Comments 7: The initial soil properties should be written in table in material section.  

Response 7: The table of initial soil characteristics is located in the materials section.

 

Comments 8: Line204. You shouldn’t use pronoun (such as we ) in scientific paper.  

Response 8: Agree, We have proofread the English language as requested.

 

Comments 9: Add the reference for Statistical analysis (lines from 222 to 227).

Response 9: We have added the references as requested (References 39, 40).

 

Comments 10: Lines from 229 to 231, delete the following ((. This section may be divided by ubheadings. It should provide a concise and precise description of the xperimental results, their interpretation, as well as the experimental onclusions that can be drawn)).

Response 10: Agree, We have deleted the paragraph as requested.

 

Comments 11: Lines from 361 to365, delete the following ((Mine reclamation s an effective trategy for rapidly restoring vegetation within a short timeframe while imultaneously improving soil physical structure, chemical com- position, and icrobial properties. The synergistic changes in post-reclamation vegetation, oil physicochemical properties, and microbial communities collectively etermine the functional state and multifunctionality of the reclaimed cosystem)) You should discuss your obtained results directly.

Response 11: Agree, We have deleted the paragraph as requested.

 

Comments 11: Replace the references (16, 18,19,22) with modern reference

Response 11: Agree, We have replaced references 16, 18, and 22 as requested and removed reference 19.

Reviewer 4 Report

Comments and Suggestions for Authors

The topic selection of the article is current, because the reclamation of degraded mining areas is critical for both environmental protection and sustainable economic development. The reclamation of mining areas is a complex process that involves the physical and chemical restoration of the area, followed by biological rehabilitation, with the aim of returning the area to its original or new use. The article is generally relevant in terms of form and content, well edited and understandable. The subsections and structure of the manuscript are appropriate. The literature background is adequately detailed, the applied methods and statistical analysis are correct. The results provide several new and original research findings and the results can contribute to enriching and expanding the topic of application of organic fertilizers for reclamation of mining areas. The conclusions are correct and consistent with the contents of the manuscript.

Comments:

L. 167-169: What methods and techniques (sand/kaolin box, pressure membrane etc.) were used to determine the hydraulic parameters of the soil? Is gravimetric method used to determine the weight of the samples? Maximum water holding capacity is actually equal to the total porosity, therefore the two parameters are practically the same.

L. 179: What were the soil temperature conditions during the year? Soil microbial activity is minimal below 5 degrees Celsius, or stops at temperatures around freezing. What impact did this have on the results in alpine climate?

L. 193: Tables and diagrams must be able to be interpreted independently. Please use the legend of abbreviations for tables and diagrams.

Author Response

Comments 1: L. 167-169: What methods and techniques (sand/kaolin box, pressure membrane etc.) were used to determine the hydraulic parameters of the soil? Is gravimetric method used to determine the weight of the samples? Maximum water holding capacity is actually equal to the total porosity, therefore the two parameters are practically the same.

Response 1: We thank the reviewer for this valid comment. This study determined maximum water-holding capacity using the ring-knife flooding method and calculated total porosity based on soil bulk density and particle density to quantify core parameters for soil water conservation. It must be explicitly noted that while closely related, these two parameters represent distinct physical processes: maximum water-holding capacity measures the soil's water retention capability, while total porosity reflects the proportion of pore space within the soil. This distinction determines that they elucidate soil function from the perspectives of water retention and physical structure, respectively. In the context of this study's high-altitude mining area—a region where soil structure and function urgently require restoration—simultaneously obtaining these two parameters is crucial. This not only aids in assessing the current state of soil recovery but also provides a foundation for deeply analyzing its water conservation mechanisms and responses to ecological restoration.

 

Comments 2: L. 179: What were the soil temperature conditions during the year? Soil microbial activity is minimal below 5 degrees Celsius, or stops at temperatures around freezing. What impact did this have on the results in alpine climate?

Response 2: We thank the reviewer for this valid comment. Regarding the limitations of our research concerning soil temperature, we have outlined our next research plans in detail in the discussion section (line 415-422).

 

Comments 3: Tables and diagrams must be able to be interpreted independently. Please use the legend of abbreviations for tables and diagrams.

Response 3: Agree, We have provided abbreviated explanations for the tables and charts as requested（line 203-210）.