2023 Fiscal Year Final Research Report
Increased moisture fluctuation and priming effect: Impact assessment for advancing the prediction of forest soil carbon dynamics
| Project/Area Number |
21H02231
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Review Section |
Basic Section 40010:Forest science-related
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| Research Institution | Niigata University |
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Principal Investigator |
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| Co-Investigator(Kenkyū-buntansha) |
小嵐 淳 国立研究開発法人日本原子力研究開発機構, 原子力科学研究部門 原子力科学研究所 原子力基礎工学研究センター, 研究主席 (30421697)
平舘 俊太郎 九州大学, 農学研究院, 教授 (60354099)
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| Project Period (FY) |
2021-04-01 – 2024-03-31
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| Keywords | 土壌炭素動態 / 水分変動 / プライミング効果 / 火山灰土壌 / 気候変動 / 土壌有機物分解 / 降水パターン / 気象激甚化 |
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| Outline of Final Research Achievements |
Ten soils collected from forests and grasslands in Japan were incubated under wet-dry cycle conditions (DWC) that simulated increased moisture fluctuations, in an attempt to elucidate the phenomenon of soil CO2 release increase. In all soils, the CO2 release rate in the DWC treatment was greater than that in the control treatment with no moisture fluctuations. However, in high-temperature conditions, the increase in CO2 release due to the DWC was mitigated, and Q10 tended to decrease. The abundance of organo-metal complexes in the soil was suggested as a soil physicochemical property that predicts differences in the increased rate of CO2 release among soils. A decrease in microbial biomass due to increased moisture fluctuations was also suggested. These soil physicochemical properties may be related to the reduction of Q10 for soil organic matter decomposition and the occurrence of the priming effect suggested by this.
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| Free Research Field |
陸域環境動態
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| Academic Significance and Societal Importance of the Research Achievements |
これまで土壌炭素濃度を高める働きがあるとして注目されてきた金属－有機物複合体について、水分変動増大環境に対する脆弱性を示唆できた点において、本研究成果は独自性が高く、森林土壌の炭素動態予測高度化に対しても大きな意義を有している。また、乾湿サイクル条件における有機物分解の温度感受性（Q10）の低下も興味深い。本研究成果により、炭素動態予測モデルやこうしたモデルに基づいた地球環境変化の将来予測に潜む不確実性の低減につながることが期待される。
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