Modeling Grassland Soil Organic Carbon Dynamics Under Climate Change Scenarios Using the EcoSIM Model

Soil organic carbon (SOC) is a key component of soil functioning and a major driver of the terrestrial carbon cycle, influencing ecosystem productivity, soil fertility, and climate feedbacks. Anticipating how SOC stocks respond to climate change and management practices is essential for designing sustainable land-use strategies and improving carbon sequestration assessments. In this study, we apply the process-based EcoSIM model to simulate SOC dynamics in temperate grassland ecosystems under contrasting climate change scenarios. The model integrates site-specific soil properties, climate forcing, and management practices to represent carbon inputs, decomposition processes, and transfers among soil organic matter pools.We explored multiple climate projections to assess the combined effects of increasing temperatures, altered precipitation regimes, and moisture stress on SOC turnover. Particular attention was given to the interactions between plant productivity, microbial activity, and soil moisture dynamics, which strongly regulate organic matter decomposition. Model simulations reveal that warming generally enhances SOC mineralization, leading to potential long-term carbon losses, especially under scenarios characterized by frequent drought events. However, results also show that management strategies such as adjusted cutting frequency and fertilization regimes can partially offset climate-induced SOC declines by sustaining biomass inputs and stabilizing soil carbon pools.Our findings highlight the importance of using dynamic, process-oriented models to capture the non-linear and interacting controls of climate and management on SOC dynamics. This work contributes to improving predictive frameworks for soil carbon modeling and provides insights relevant to climate mitigation strategies, sustainable grassland management, and assessments of soil resilience under future environmental change.