Review Reports

Round 1

Reviewer 1 Report

-Line 38: “ nature-based solutions” was mentioned only one time here. This study was not conducted nature-based solutions.

-Lines 106-120: What are the hypothesis of this study?

-Line 126, 134, 137: Figure S1 and Figure S2 should be Figure 1 and Figure 2. If you want to use “S1” “S2”, move them to appendix or supplemental.

-Lines 136-139: The other soil nutrients were not provided. Why?

-Line 148: Why August 2024 was not measured the data? So, how to obtain the data for one year?

-Lines 363-370: Effect of biochar on soil CO2 fluxes should be deeper discussed. [https://doi.org/10.3390/agronomy11081559]

-Lines 404-407: GHG emissions under AWD vary depending soil texture, which is different soil microbial activity. This matter must be mentioned and see this study [https://doi.org/10.1038/s41598-025-09843-w]

-Figure 1: Which month to which month for each season? It should be mentioned in the Climate section.

-Lines 470-476: This study did not focus on NbS. How this study can be linked?

-Line 492: Did you have the patents in this study?

-Line 38: “ nature-based solutions” was mentioned only one time here. This study was not conducted nature-based solutions.

-Lines 106-120: What are the hypothesis of this study?

-Line 126, 134, 137: Figure S1 and Figure S2 should be Figure 1 and Figure 2. If you want to use “S1” “S2”, move them to appendix or supplemental.

-Lines 136-139: The other soil nutrients were not provided. Why?

-Line 148: Why August 2024 was not measured the data? So, how to obtain the data for one year?

-Lines 363-370: Effect of biochar on soil CO2 fluxes should be deeper discussed. [https://doi.org/10.3390/agronomy11081559]

-Lines 404-407: GHG emissions under AWD vary depending soil texture, which is different soil microbial activity. This matter must be mentioned and see this study [https://doi.org/10.1038/s41598-025-09843-w]

-Figure 1: Which month to which month for each season? It should be mentioned in the Climate section.

-Lines 470-476: This study did not focus on NbS. How this study can be linked?

-Line 492: Did you have the patents in this study?

Author Response

Reply to Reviewer 1  

-Line 38: “ nature-based solutions” was mentioned only one time here. This study was not conducted nature-based solutions.

Response: Thank you for the committee member's reminder; the keywords have been corrected.

 

-Lines 106-120: What are the hypothesis of this study?

Response: Our research hypothesis is "We hypothesize that biochar, when applied alone or in combination with organic fertilizer, can reduce GHG emissions while enhancing photosynthetic carbon uptake compared to fertilizer-only treatments. " in line 112-114.

 

-Line 126, 134, 137: Figure S1 and Figure S2 should be Figure 1 and Figure 2. If you want to use “S1” “S2”, move them to appendix or supplemental.

Response: Thank you for the committee's suggestion; we have revised the legend order.

 

-Lines 136-139: The other soil nutrients were not provided. Why?

Response: We sincerely thank the reviewers for their valuable comments. The primary objective of this study was to quantify the seasonal dynamics of greenhouse gas fluxes (CO₂ and N₂O) and photosynthetic carbon assimilation in coastal shelterbelts under different remediation strategies. Given the specific environmental context of the study site (coastal saline-alkaline sandy soils), our soil characterization prioritized the major stressors influencing plant and microbial physiology, particularly soil salinity and pH, as reported in Section 2.1.34. We acknowledge that a comprehensive analysis of other soil nutrient dynamics (e.g., available nitrogen, phosphorus, and potassium) would contribute to a deeper understanding of their mechanisms of action. However, due to the specific focus and resource allocation of this field monitoring activity, we were unable to track these parameters throughout the year. We explicitly acknowledge this limitation in the discussion section (lines 419), stating: "...a limitation of this study is the lack of detailed soil sample analysis to account for these factors." Given these factors, we fully agree with the reviewers' assessment and have made this a focus of our future research to better elucidate the nutrient-driven mechanisms.

 

-Line 148: Why August 2024 was not measured the data? So, how to obtain the data for one year?

Response: Thank you for the committee's suggestion. Our experiment will run from August 31, 2023 to May 15, 2024. Due to cost and configuration issues, the measurement work of this experiment will be terminated after completing the four seasons of the year.

 

-Lines 363-370: Effect of biochar on soil CO2 fluxes should be deeper discussed. [https://doi.org/10.3390/agronomy11081559]

Response: Thank you for the committee's suggestion. We have added to the discussion of the research results on the impact of biochar on CO2 flux: "Moreover, studies have shown that the application of biochar can reduce soil carbon dioxide emissions by 28.2% and 57.7% (under the conditions of 3 kg/m² and 1 kg/m²) [38]. In our study, similar results were found, the B+F treatment produced moderate CO₂ fluxes relative to the fertilizer-only plots, suggesting that the co-application of biochar and composted inputs may temper microbial decomposition rates and modulate carbon release." in line 373-378.

 

39. Bovsun, M.A.; Castaldi, S.; Nesterova, O.V.; Semal, V.A.; Sakara, N.A.; Brikmans, A.V.; Khokhlova, A.I.; Karpenko, T.Y. Effect of Biochar on Soil CO2 Fluxes from Agricultural Field Experiments in Russian Far East. Agronomy 2021, 11, 1559.

 

-Lines 404-407: GHG emissions under AWD vary depending soil texture, which is different soil microbial activity. This matter must be mentioned and see this study [https://doi.org/10.1038/s41598-025-09843-w]

Response: Thanks to the committee members for their suggestions, we have added relevant research insights to the discussion: "Under these greenhouse gas emission trends, the total amount of emissions will vary depending on soil texture, which is related to soil microbial activity, and this is something that needs to be considered in future research [50]." in line 419-422.

 

50. Arunrat, N.; Sereenonchai, S.; Uttarotai, T. Effects of soil texture on microbial community composition and abundance under alternate wetting and drying in paddy soils of central Thailand. Sci. Rep. 2025, 15, 24155.

 

-Figure 1: Which month to which month for each season? It should be mentioned in the Climate section.

Response: We thank the committee members for their suggestions and have added the following to the Materials and Methods section: "Amendments were applied on four occasions: August 31, 2023 (autumn); November 22, 2023 (winter); February 22, 2024 (spring); and May 15, 2024 (summer)." in line 153-154.

 

-Lines 470-476: This study did not focus on NbS. How this study can be linked?

Response: Thank you for the question. We have reconsidered and revised the sentence to reflect on its future application: "Furthermore, evaluating the performance of bamboo species alongside other reforestation or afforestation alternatives may assist in optimizing land-use decisions [2, 62]." in line 481-483.

 

-Line 492: Did you have the patents in this study?

Response: Thank you for the question. We have no plans to apply for patents or other patents related to this research.

Author Response File: Author Response.docx

Reviewer 2 Report

The manuscript presents a field-based study assessing greenhouse gas (GHG) emissions (CO₂ and N₂O) and carbon assimilation under four soil treatments in bamboo shelterbelts. It is well structured, methodologically detailed, and relevant to nature-based climate solutions. The study adds valuable empirical data from saline coastal soils in Taiwan, a region under-represented in the literature. However, the manuscript requires moderate to major revisions to improve clarity, contextualization, and presentation of results.

1/ The introduction is comprehensive but somewhat descriptive. Clarify what specific gap this study fills beyond confirming known effects of biochar and compost on GHG emissions.

2/ The trade-off hypothesis should be emphasized earlier with a clear conceptual framework linking bamboo physiology, soil chemistry, and biochar interactions.

3/Replication: Only three clumps per treatment may be insufficient for robust inference. Discuss limitations in statistical power and potential spatial heterogeneity.

4/ Temporal sampling: Monthly GHG measurements may miss short-term flux spikes. Acknowledge that cumulative emissions might be underestimated.

5/ Soil properties: Baseline soil carbon, nitrogen, and moisture data are missing. These are essential to interpret differences in GHG fluxes.

6/  Equation formatting (Equations 2–4) is inconsistent, making readability difficult. Simplify notation and verify typographical accuracy.

7/Some figures (e.g., Figures 1–3) require clearer axis labels, units, and statistical notations.

8/ The discussion mixes interpretation with literature review. Separate results interpretation (site-specific patterns) from comparative discussion with external studies.

9/ The explanation of correlation (Table 1) is repetitive and could be condensed; emphasize the ecological reasoning rather than statistical reporting.
10/ The manuscript is grammatically correct but occasionally verbose. Simplify overly technical sentences.
11/ Ensure consistent tense use (past tense for methods/results, present tense for interpretation).
12/ Avoid redundancy (e.g., “This result highlights…” repeated several times).

13/ The conclusion section should be more concise and policy-relevant. Discuss how findings can inform Taiwan’s carbon offset or bamboo management strategies.

14/ Quantify mitigation potential (e.g., annual CO₂-equivalent reduction per hectare) if data allow.
15/ Figures S1–S2 and main text figures should be integrated with clear captions (seasonal scales, units, and sample sizes).

16/ Some supporting figures reference data (e.g., 2019–2020) inconsistent with the 2023–2024 field period—check for errors.

The manuscript presents a field-based study assessing greenhouse gas (GHG) emissions (CO₂ and N₂O) and carbon assimilation under four soil treatments in bamboo shelterbelts. It is well structured, methodologically detailed, and relevant to nature-based climate solutions. The study adds valuable empirical data from saline coastal soils in Taiwan, a region under-represented in the literature. However, the manuscript requires moderate to major revisions to improve clarity, contextualization, and presentation of results.

1/ The introduction is comprehensive but somewhat descriptive. Clarify what specific gap this study fills beyond confirming known effects of biochar and compost on GHG emissions.

2/ The trade-off hypothesis should be emphasized earlier with a clear conceptual framework linking bamboo physiology, soil chemistry, and biochar interactions.

3/Replication: Only three clumps per treatment may be insufficient for robust inference. Discuss limitations in statistical power and potential spatial heterogeneity.

4/ Temporal sampling: Monthly GHG measurements may miss short-term flux spikes. Acknowledge that cumulative emissions might be underestimated.

5/ Soil properties: Baseline soil carbon, nitrogen, and moisture data are missing. These are essential to interpret differences in GHG fluxes.

6/  Equation formatting (Equations 2–4) is inconsistent, making readability difficult. Simplify notation and verify typographical accuracy.

7/Some figures (e.g., Figures 1–3) require clearer axis labels, units, and statistical notations.

8/ The discussion mixes interpretation with literature review. Separate results interpretation (site-specific patterns) from comparative discussion with external studies.

9/ The explanation of correlation (Table 1) is repetitive and could be condensed; emphasize the ecological reasoning rather than statistical reporting.
10/ The manuscript is grammatically correct but occasionally verbose. Simplify overly technical sentences.
11/ Ensure consistent tense use (past tense for methods/results, present tense for interpretation).
12/ Avoid redundancy (e.g., “This result highlights…” repeated several times).

13/ The conclusion section should be more concise and policy-relevant. Discuss how findings can inform Taiwan’s carbon offset or bamboo management strategies.

14/ Quantify mitigation potential (e.g., annual CO₂-equivalent reduction per hectare) if data allow.
15/ Figures S1–S2 and main text figures should be integrated with clear captions (seasonal scales, units, and sample sizes).

16/ Some supporting figures reference data (e.g., 2019–2020) inconsistent with the 2023–2024 field period—check for errors.

Author Response

Reply to Reviewer2  

The manuscript presents a field-based study assessing greenhouse gas (GHG) emissions (CO₂ and N₂O) and carbon assimilation under four soil treatments in bamboo shelterbelts. It is well structured, methodologically detailed, and relevant to nature-based climate solutions. The study adds valuable empirical data from saline coastal soils in Taiwan, a region under-represented in the literature. However, the manuscript requires moderate to major revisions to improve clarity, contextualization, and presentation of results.

Response: We are honored to thank the committee members for their positive summary and response.

 

1. The introduction is comprehensive but somewhat descriptive. Clarify what specific gap this study fills beyond confirming known effects of biochar and compost on GHG emissions.

Response: We thank the reviewer for this constructive observation. We agree that while the general effects of biochar and compost are well-documented in agricultural crops, their application in coastal shelterbelt ecosystems—specifically under saline-alkaline soil conditions—remains a critical knowledge gap.

To address this, we have revised the Introduction to more clearly articulate the specific contributions of this study. Rather than simply confirming known amendment effects, this study fills the following gaps:

Environmental Context: Most biochar studies focus on acidic or neutral soils. Empirical evidence regarding biochar’s efficacy in mitigating GHGs in subtropical saline-alkaline sandy soils is limited. Our study addresses how these specific stress conditions interact with amendments to influence microbial GHG dynamics.

Ecosystem Specificity: Unlike intensively managed annual crops, bamboo shelterbelts serve a dual function of carbon sequestration and coastal protection. Understanding the carbon dynamics in this specific agroforestry system.

Carbon Trade-off Analysis: A key gap we address is the quantified trade-off between nutrient-driven photosynthetic carbon gain and soil GHG emissions. This study goes beyond emission monitoring to evaluate the 'net' climate benefit by integrating physiological carbon assimilation data.

We have refined the final paragraph of the Introduction (Lines 58-73) to explicitly highlight these distinct contributions: “However, extrapolating these known effects to coastal saline-alkaline environments remains problematic due to the unique microbial and physiological stresses present in these systems. There is a critical lack of empirical data on how biochar and organic fertilizers interact to influence the carbon trade-off—balancing photosynthetic gain against respiratory losses—specifically within bamboo shelterbelts. This study bridges this gap by using fertilizer and biochar application trials to monitor the dynamic state of greenhouse gas emissions in the field.”

 

2. The trade-off hypothesis should be emphasized earlier with a clear conceptual framework linking bamboo physiology, soil chemistry, and biochar interactions.

Response: We sincerely thank the reviewer for pointing out this structural area for improvement. We agree that explicitly defining the conceptual framework linking plant physiology, soil chemistry, and amendment interactions earlier in the Introduction will significantly strengthen the study's rationale.To address this, we have inserted a new paragraph in the Introduction (preceding the objectives) to clearly articulate the mechanistic links and the 'trade-off' hypothesis:

Physiology vs. Emissions: We explain that while nutrient inputs (organic fertilizers) are necessary to maximize bamboo photosynthetic capacity and biomass (Physiology), they simultaneously fuel microbial nitrification-denitrification processes, leading to elevated N2O fluxes (Soil Chemistry). This creates an inherent 'productivity-emission trade-off.

Biochar as a Mediator: We then introduce biochar’s role in this framework. Due to its porosity and surface charge, biochar interacts with soil chemistry by adsorbing excess nitrogen and improving aeration. We hypothesize that this interaction can decouple the relationship between fertilization and emissions—maintaining high carbon uptake while suppressing GHG pulses.

We have revised the text to ensure this logical flow leads directly into our hypothesis." However, extrapolating these known effects to coastal saline-alkaline environments remains problematic due to the unique microbial and physiological stresses present in these systems. There is a critical lack of empirical data on how biochar and organic fertilizers interact to influence the carbon trade-off—balancing photosynthetic gain against respiratory loss-es—specifically within bamboo shelterbelts for a critical challenge lies in the carbon trade-off mechanism. While organic fertilizers are essential for overcoming nutrient limitations and maximizing photosynthetic carbon assimilation in bamboo, they typically elevate the risk of N₂O emissions through accelerated microbial nitrogen transformations. This creates a conflict between maximizing carbon uptake and minimizing soil emissions. Theoretically, biochar amendment can resolve this conflict by interacting with soil chemistry—specifically by adsorbing labile nitrogen and improving soil aeration. This suggests a potential conceptual framework where biochar acts to decouple agronomic productivity from emission intensity, particularly in saline environments where soil structure is often compromised. This study bridges this gap by using fertilizer and biochar application trials to monitor the dynamic state of greenhouse gas emissions in the field." In Lines 58-73

 

 

3. Replication: Only three clumps per treatment may be insufficient for robust inference. Discuss limitations in statistical power and potential spatial heterogeneity.

Response: We appreciate the reviewer’s valid concern regarding the sample size (n=3) and its implications for statistical power and spatial heterogeneity.While we acknowledge that a larger sample size would improve statistical robustness, we would like to highlight three key points that support the validity of our findings: 1) Strength of Observed Effects: Despite the limited replication, the differences between treatments (particularly between Fertilizer and Biochar+Fertilizer) were sufficiently large to yield statistically significant results (p < 0.05) in both GHG emissions and carbon assimilation. This suggests that the treatment effect size was substantial enough to overcome the limitations of low statistical power. 2) Field Logistics: Unlike pot experiments, measuring soil GHG fluxes in a mature bamboo shelterbelt using static chambers is labor-intensive. The sample size of three clumps per treatment was a necessary trade-off to allow for high-frequency (monthly) and detailed seasonal monitoring over a full year. 3) Spatial Heterogeneity: We have explicitly acknowledged the limitation regarding soil spatial variation. As stated in the Discussion (Lines 416-420), we noted that "micro-scale spatial variations in soil salinity, organic matter content... could have existed even within the same experimental site" We have expanded this section in the revised manuscript to further discuss how low replication warrants caution in interpreting smaller, non-significant trends, while reaffirming confidence in the major treatment impacts observed.

 

4. Temporal sampling: Monthly GHG measurements may miss short-term flux spikes. Acknowledge that cumulative emissions might be underestimated.

Response: We fully accept the reviewer’s valid critique regarding the temporal resolution of our sampling. We acknowledge that monthly sampling intervals  may miss short-term emission pulses ('hot moments') triggered immediately following rainfall or fertilization events, leading to a potential underestimation of the absolute cumulative annual emissions. However, we argue that the comparative conclusions of the study remain robust for the following reasons: Synchronized Sampling: All treatments were measured simultaneously under identical environmental conditions. Therefore, the relative differences and the ranking of treatments (e.g., the significant reduction of N2O in Biochar treatments compared to Fertilizer-only, as noted in Lines 157-159 ) remain valid indicators of the amendment effects. 2. Seasonal Trends: Despite the monthly interval, our data successfully captured the expected seasonal dynamics, including peak emissions during the warm, wet summer months (Figure 3 & 4).

In response to this comment, we have revised the Discussion section (Line 450-453) to explicitly state: 'It is important to note that monthly sampling may not capture short-term flux spikes. Consequently, the cumulative emission values reported here should be interpreted as conservative estimates, although the relative trends among treatments remain representative.

5. Soil properties: Baseline soil carbon, nitrogen, and moisture data are missing. These are essential to interpret differences in GHG fluxes.

Response: We thank the reviewer for highlighting this important aspect. We acknowledge that continuous monitoring of soil carbon, nitrogen, and moisture would have provided deeper mechanistic insights. However, due to the specific focus and resource constraints of this field study, we adopted the following approach: 1) Soil Moisture Proxy: While direct soil moisture content was not monitored, we utilized precipitation data as a key environmental driver. Our analysis showed a strong positive correlation between rainfall and GHG fluxes (specifically N2O, r = 0.71, p < 0.001), as detailed in Table 1 and Lines 160-161. This suggests that precipitation served as an effective proxy for soil water status in explaining emission trends in this sandy soil system. 2) Site-Specific Focus: Given the coastal nature of the experimental site, our baseline characterization prioritized the dominant environmental stressors: Soil Salinity and pH, which were reported in Section 2.1.3 (pH 8.5, Salinity 0.1-0.25%). 3) Acknowledged Limitation: We have explicitly stated the lack of detailed soil nutrient and moisture tracking as a limitation in the Discussion. Specifically, Line 419 notes the lack of detailed soil sample analysis, and Line 435 explicitly acknowledges that "a limitation of the present study is that we did not measure changes in soil moisture". We hope the reviewer accepts these environmental proxies and our honest disclosure of limitations as sufficient for the scope of this study.

 

6. Equation formatting (Equations 2–4) is inconsistent, making readability difficult. Simplify notation and verify typographical accuracy.

Response: We sincerely apologize for the formatting inconsistencies and typographical errors in the equations, which were likely introduced during the document conversion process.We have carefully reconstructed Equations 2, 3, and 4 using standard mathematical notation to ensure readability and accuracy. The variables have been clearly defined, and the syntax has been simplified as follows:

Equation 2 has been formatted to clearly represent the non-rectangular hyperbola model for photosynthetic rate.

Equations 3 and 4 have been corrected to use proper integral notation for estimating daily carbon assimilation and respiration.

These corrections have been applied in the revised manuscript to meet the journal’s publication standards.

 

7. Some figures (e.g., Figures 1–3) require clearer axis labels, units, and statistical notations.

Response: Thank you for the committee's suggestion; we have revised the way the charts are presented.

 

8. The discussion mixes interpretation with literature review. Separate results interpretation (site-specific patterns) from comparative discussion with external studies.
9. The explanation of correlation (Table 1) is repetitive and could be condensed; emphasize the ecological reasoning rather than statistical reporting.
10. The manuscript is grammatically correct but occasionally verbose. Simplify overly technical sentences.
11. Ensure consistent tense use (past tense for methods/results, present tense for interpretation).
12. Avoid redundancy (e.g., “This result highlights…” repeated several times).

Response: Thank you for the committee member's suggestion; we have adjusted the sentence structure:” 4.1 CO₂ Emissions

The elevated CO₂ efflux observed in the fertilizer (F) and biochar-plus-fertilizer (B+F) treatments in this study can be attributed to a rise in heterotrophic respiration, likely stimulated by microbial proliferation in response to nutrient availability [30]. Enhanced nitrogen levels are known to promote root development and rhizosphere metabolic activity, thereby contributing to higher respiration rates [31, 32]. Moreover, the peak CO₂ emissions recorded during the summer season reflect optimal microbial and root functioning under warm and moist conditions [33]. Crucially, while fertiliza-tion drove total respiration up, the B+F treatment produced moderate CO₂ fluxes rela-tive to the fertilizer-only plots. This suggests that the co-application of biochar and composted inputs successfully tempered microbial decomposition rates and modulat-ed carbon release in this saline soil system.

These findings are consistent with previous research highlighting the influence of environmental and management factors on GHG dynamics [34, 35]. The pattern ob-served here exemplifies a common trade-off in tropical agroecosystems, where productivity gains are often accompanied by elevated emission intensities [36]. Re-garding biochar effects, although some studies attribute increased emissions to prim-ing effects from labile carbon [17, 37], our results align more closely with research demonstrating microbial immobilization and stabilization of organic carbon [38]. For instance, Bovsun et al. [39] reported that biochar application could reduce soil CO₂ emissions by 28.2% to 57.7% (at rates of 3 kg/m² and 1 kg/m², respectively). The fact that our B+F treatment maintained lower fluxes than the F treatment corroborates this stabilizing potential, distinguishing biochar’s role from that of purely labile organic amendments.

4.2. N₂O Emissions and Nitrogen Transformation Pathways

Our results showed that greenhouse gas (GHG) emissions varied significantly among treatment types. Plots treated with nitrogen fertilizer (vermicompost) exhibited the highest N2O emissions, particularly during the summer and autumn seasons. The rapid nitrogen availability in vermicompost creates microbial “hotspots,” triggering pulses of GHG emissions [40]. This observation is consistent with Shcherbak et al. [41], who reported a nonlinear escalation of N2O fluxes with increased nitrogen fertilizer rates, largely due to intensified nitrification–denitrification pathways [42,43]. These findings are also in line with the global trend reported by Amirahmadi et al. [44], whose meta-analysis revealed that combined biochar and chemical fertilizer (BCF) treatments led to a 62.9% increase in N2O emissions. In contrast, the B+F treatment in our study resulted in lower emissions. This is attributed to its gradual nutrient release and higher carbon-to-nitrogen ratio, which promotes microbial nitrogen immobiliza-tion and limits denitrification. Charles et al. [45] noted that while organic fertilizers display greater variability, they typically reduce average N2O output due to improved microbial stability. Furthermore, combining biochar with organic fertilizers has been shown to enhance nitrogen retention, alter microbial community structure, and sup-press denitrification processes [40, 46]. These findings suggest that, although reducing fertilizer use can lower N2O emissions, fertilization remains essential in saline–alkaline farmlands to ensure yield stability. Under such conditions, the integration of biochar with fertilization emerges as a priority strategy for mitigating N2O emissions while sustaining agricultural productivity [24, 25].

Environmental factors also modulate GHG fluxes. Rainfall was significantly cor-related with N2O emissions in our study, reaffirming the findings by Xia et al. [47], who emphasized that water-filled pore space (WFPS) strongly influences N2O emis-sions, with the highest fluxes occurring when WFPS ranges between 50% and 90%. Such mechanisms may explain why periodic drying cycles in paddy fields, as reported by Loaiza et al. [48], tend to increase N2O emissions under alternate wetting and dry-ing (AWD) conditions. During the drying phase, enhanced nitrification can stimulate subsequent aerobic N2O release, while re-flooding may trigger denitrification, further elevating emissions [32, 49]. On the other hand, the experimental results of Yang et al. [20] indicated that reducing fertilizer application decreases N2O emissions and can further suppress the effects of soil moisture fluctuations. In addition to moisture, the total amount of emissions will vary depending on soil texture, which is related to soil microbial activity, and this is a critical factor that needs to be considered in future re-search [50]. However, a limitation of the present study is that we did not measure changes in soil moisture or spatial texture variations, which prevents a more direct analysis of this mechanism. Nevertheless, the application of biochar, due to its porous structure, can further mitigate N2O formation under fluctuating moisture conditions [51], a process consistent with the patterns observed in this study.

Regarding the frequency of greenhouse gas (GHG) measurements, the develop-ment of Tier 3 emission factors typically requires monitoring at weekly or biweekly intervals to capture short-term fluctuations. However, numerous studies on GHG emissions from paddy fields have demonstrated that conducting measurements every 7–10 days during critical growth stages (e.g., tillering, heading, and irrigation periods) is sufficient to effectively capture the peaks and temporal trends of CH4 and N2O emissions. For example, experiments conducted in China, Korea, and Japan have suc-cessfully employed 7–10 day intervals to obtain reliable estimates of seasonal cumula-tive emissions, which have been widely published in international journals [18, 20, 21, 52-54]. Accordingly, the measurement intervals adopted in this study were designed based on these references and are statistically robust in reflecting both seasonal varia-tions and treatment effects. It is important to note that monthly sampling may not capture short-term flux spikes. Consequently, the cumulative emission values reported here should be interpreted as conservative estimates, although the relative trends among treatments remain representative. These results provide empirical evidence that integrated use of biochar and compost represents a viable strategy to reduce GHG intensity while sustaining photosynthetic performance. Finally, the coastal site’s saline conditions likely influenced these dynamics; the enhanced performance under biochar treatments may partly reflect improved osmotic buffering, which warrants further in-vestigation through direct salinity measurements in future studies.” in line 363-442.

 

13. The conclusion section should be more concise and policy-relevant. Discuss how findings can inform Taiwan’s carbon offset or bamboo management strategies.

Response: Thanks to the committee members’ suggestions, we have adjusted the way the conclusion sentence is presented: " The joint application of biochar and fertilizer significantly upregulated bamboo photosynthetic capacity (An) and leaf area index, driving substantial biomass accumu-lation. With carbon assimilation estimates reaching 1.8–18.5 kg CO2 per clump per sea-son, nutrient management emerges as a critical lever for maximizing ecosystem productivity. In the context of Taiwan’s “Net Zero 2050” goals, these findings validate the intensively managed bamboo forests as high-efficiency carbon sinks. Specifically, the superior sequestration rates observed in biochar-amended plots pro-vide the necessary scientific baseline for developing bamboo-specific carbon offset methodologies and establishing the "additionality" required for carbon credit certification. Future forest management policies should therefore prioritize precision fertiliza-tion and biochar integration to optimize bamboo's contribution to regional carbon mit-igation potential strategies." in line 485-495.

 

14. Quantify mitigation potential (e.g., annual CO₂-equivalent reduction per hectare) if data allow.

Response: Thanks to the committee member's suggestion, we have adjusted the way the conclusion sentence is presented: "The enhancement of bamboo's photosynthetic performance under fertilization aligns with well-documented physiological, whereby increased nitrogen availability promotes chlorophyll synthesis, Rubisco enzyme activity, and stomatal regulation mechanisms [55, 56]. Consequently, the elevated net assimilation rates (An) observed in fertilizer (F) and biochar-plus-fertilizer (B+F) plots mirror responses seen in other high-biomass, fast-growing species such as Eucalyptus [57]. In terms of productivity, carbon assimilation estimates based on leaf area index (LAI) ranged from 1.8 to 18.5 kg CO2 per clump per season. These values ​​are consistent with, or even surpass, those reported for intensively managed bamboo plantations in subtropical China [5, 6]. To contextualize these findings for carbon inventory purposes, we upscaled these clump-level rates assuming a standard planting density of 400 clumps h-1. The results demonstrate a significant increase in mitigation potential: from 0.72 tons CO2e ha-1 in the unfertilized control to 7.4 tons CO2e ha-1 per growing season in the biochar-fertilized treatment. This ten-fold increase underscores the scalability of nutrient management strategies in enhancing the carbon sink function of bamboo forests." in line 485-495.

 

15. Figures S1–S2 and main text figures should be integrated with clear captions (seasonal scales, units, and sample sizes).
16. Some supporting figures reference data (e.g., 2019–2020) inconsistent with the 2023–2024 field period—check for errors.

Response: We appreciate the committee member's suggestion and have revised the legend.

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

Accept in present form.

Accept in present form.

Reviewer 2 Report

The revision is fine to me now 

The revision is fine to me now