17:15 〜 19:15
[ACG39-P01] Simulation of Soil Organic Carbon Storage Changes in Agricultural Lands of a river basin in Central Taiwan
キーワード：Process-based model, SOC sequestration potential, Land use
Soil, as the largest terrestrial carbon reservoir, plays a pivotal role in the global carbon cycle and climate change, holding approximately 3 to 4 times of the carbon stored in the atmosphere and vegetation. The stability and storage of Soil Organic Carbon (SOC) are influenced by multiple factors, including climatic conditions, organic matter inputs, soil physicochemical properties, microbial activity, and land use practices, which indirectly affect greenhouse gas concentrations in the atmosphere. Enhancing SOC storage not only mitigates climate change but also improves soil health, fertility, and food security.
Taiwan possesses extensive soil survey data and long-term experimental research. However, discussions on the temporal and spatial variations of SOC remain limited. This study aims to address: (1) How does SOC storage change under different carbon input scenarios? (2) Is achieving the "4 per 1000" initiative feasible? Using the Jhuoshuei River Basin in central Taiwan as the study area, the research integrates a process-based soil carbon dynamic model with localized data, including historical climate observations, soil analyses, and land use /land cover, to simulate SOC changes under various land use and management scenarios.
SOC sequestration potential increases with higher carbon input levels. Between 2022 and 2041, compared to 2021, the average SOC sequestration potential under the business-as-usual (BAU) scenario and scenarios with carbon inputs increased by 5% (SSM 1), 10% (SSM 2), and 20% (SSM 3) relative to BAU were -0.01, 0.04, 0.08, and 0.17 tC/ha/yr, respectively. However, even with a 20% annual increase in carbon inputs, achieving the "4 per 1000" target remains unfeasible, likely due to the subtropical climate in the study area, where high temperatures and abundant rainfall accelerate organic matter decomposition, limiting long-term SOC retention. In terms of land use, upstream areas are predominantly grasslands, midstream regions are characterized by orchards and drylands, and downstream regions primarily consist of paddy fields and drylands. Notably, transitioning drylands into paddy fields in downstream areas significantly enhances SOC sequestration potential compared to maintaining them as fixed drylands or paddy fields. Under unchanged carbon input scenarios, regions with lower SOC sequestration potential are concentrated in downstream towns near estuaries, while midstream towns generally exhibit higher potential.
Given the declining agricultural land area in Taiwan, the quantitative data simulated in this study provide a valuable reference for management authorities to evaluate the impacts of different land use and increased carbon input scenarios on SOC storage. Furthermore, the study identifies high carbon sequestration potential areas, which can inform agricultural land management and land use policies. By strategically allocating resources to key regions, policymakers can enhance carbon sequestration efficiency and mitigate the risks associated with soil carbon loss.
Taiwan possesses extensive soil survey data and long-term experimental research. However, discussions on the temporal and spatial variations of SOC remain limited. This study aims to address: (1) How does SOC storage change under different carbon input scenarios? (2) Is achieving the "4 per 1000" initiative feasible? Using the Jhuoshuei River Basin in central Taiwan as the study area, the research integrates a process-based soil carbon dynamic model with localized data, including historical climate observations, soil analyses, and land use /land cover, to simulate SOC changes under various land use and management scenarios.
SOC sequestration potential increases with higher carbon input levels. Between 2022 and 2041, compared to 2021, the average SOC sequestration potential under the business-as-usual (BAU) scenario and scenarios with carbon inputs increased by 5% (SSM 1), 10% (SSM 2), and 20% (SSM 3) relative to BAU were -0.01, 0.04, 0.08, and 0.17 tC/ha/yr, respectively. However, even with a 20% annual increase in carbon inputs, achieving the "4 per 1000" target remains unfeasible, likely due to the subtropical climate in the study area, where high temperatures and abundant rainfall accelerate organic matter decomposition, limiting long-term SOC retention. In terms of land use, upstream areas are predominantly grasslands, midstream regions are characterized by orchards and drylands, and downstream regions primarily consist of paddy fields and drylands. Notably, transitioning drylands into paddy fields in downstream areas significantly enhances SOC sequestration potential compared to maintaining them as fixed drylands or paddy fields. Under unchanged carbon input scenarios, regions with lower SOC sequestration potential are concentrated in downstream towns near estuaries, while midstream towns generally exhibit higher potential.
Given the declining agricultural land area in Taiwan, the quantitative data simulated in this study provide a valuable reference for management authorities to evaluate the impacts of different land use and increased carbon input scenarios on SOC storage. Furthermore, the study identifies high carbon sequestration potential areas, which can inform agricultural land management and land use policies. By strategically allocating resources to key regions, policymakers can enhance carbon sequestration efficiency and mitigate the risks associated with soil carbon loss.