藁を増やせば常に炭素が隔離されるのか？都市近郊モリソルにおける土壌炭素隔離の熱的最適化ウィンドウの解明
Does More Straw Always Sequester More Carbon? Unveiling a Thermal Optimization Window for Soil Carbon Sequestration in Peri-Urban Mollisols (原題)
Qianyi Ni, Shiyu Li, Jie Zhang, Shidong Liu
🤖 gxceed AI 要約
日本語
中国東北部のモリソル農地を対象に、作物残渣被覆（CRC）と土壌有機炭素密度（SOCD）の関係を、都市近郊の都市ヒートアイランド（UHI）条件下で解析した。XGBoostとSHAP、構造方程式モデリングを用い、CRCの寄与が約48〜50%で転換する非線形パターンを示した。CRCとSOCDの関係は空間的に不均一で、昼夜のUHIが異なる影響を与えることを明らかにした。
English
Using multi-source spatial data from Mollisol croplands in Northeast China, this study examines nonlinear associations between crop residue cover (CRC) and soil organic carbon density (SOCD) under peri-urban urban heat island (UHI) conditions. XGBoost with SHAP, SEM, and PLS-PM reveal a turning region around 48–50% CRC and contrasting day/night UHI effects. Results show spatially heterogeneous CRC–SOCD relationships, offering a basis for process-based follow-up.
Unofficial AI-generated summary based on the public title and abstract. Not an official translation.
📝 gxceed 編集解説 — Why this matters
日本のGX文脈において
日本でも農業由来の炭素隔離はJ-クレジットや環境省の農地土壌炭素貯留事業と関連するが、本論文は中国の事例であり、日本のSSBJ・有報開示への直接的示唆は限定的。ただし土壌炭素の非線形性は、農業セクターのScope 3・炭素除去クレジット設計を検討する日本企業にとって参考になる。
In the global GX context
While focused on Chinese Mollisols, the finding that residue retention does not linearly increase soil carbon challenges simplified carbon-removal assumptions relevant to global soil carbon accounting under ISSB/CSRD and voluntary carbon markets. It adds empirical nuance to how agricultural carbon sequestration is modeled in disclosure frameworks.
👥 読者別の含意
🔬研究者:土壌炭素隔離の非線形性と都市熱環境の交互作用を定量化した手法（XGBoost+SHAP+SEM）が参考になる。
🏢実務担当者:農業サプライチェーンの炭素除去・インセット設計において、残渣被覆量と炭素貯留の非線形関係を考慮する必要性を示す。
🏛政策担当者:農地炭素貯留政策やクレジット設計で、一律の残渣還元推奨ではなく熱環境を考慮した最適化が有効である可能性を示唆。
📄 Abstract（原文）
Soil organic carbon (SOC) is a major terrestrial carbon pool, and its maintenance is important for climate change mitigation. Straw retention is widely used in croplands, but the association between crop residue cover (CRC) and soil organic carbon density (SOCD) may be nonlinear and may vary under peri-urban thermal conditions. We integrated multi-source spatial datasets for Mollisol croplands in Northeast China to compare recent mean SOCD in the upper 20 cm between stable rural and rural-to-urban transition zones and to examine the associations among CRC, urban heat island (UHI) intensity, and SOCD. XGBoost combined with SHapley Additive exPlanations (SHAP) was used to quantify predictor importance and characterize the nonlinear contribution of CRC to predicted SOCD. Structural equation modeling and partial least squares path modeling were further used to assess statistical associations and interaction terms among CRC, daytime and nighttime UHIs, and SOCD. Mean SOCD was slightly higher in the transition zone than in the stable zone, whereas mean CRC did not differ significantly between the two zones. The contribution of CRC to predicted SOCD showed nonlinear dependence patterns in both zones, with a similar turning region at approximately 48–50% CRC. The lower-CRC patterns differed between zones, whereas CRC was strongly positively correlated with its SHAP value across the higher-CRC interval in both zones. Daytime and nighttime UHIs were associated with contrasting CRC-SHAP patterns, and the estimated interaction effects differed between the stable and transition zones. These results reveal nonlinear and spatially heterogeneous associations between CRC and SOCD under peri-urban thermal conditions and provide a basis for further temporal and process-based investigation.
🔗 Provenance — このレコードを発見したソース
- openalex https://doi.org/10.3390/land15091760first seen 2026-09-25 04:45:46
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