Investigating and simulating the effect of climate change, grazing and manure application on organic carbon storage of forest soils at different altitudes with the Century model

Forest soils are recognized as one of the most important carbon sinks on Earth, playing a critical role in climate balance and greenhouse gas mitigation. This study investigated the effects of altitude, climate change, grazing, and manure application on soil organic carbon (SOC) stock in forest soils of Talesh County, Iran. The Century model was used to investigate the effects of climate and management factors on soil organic carbon storage. The results showed that SOC stock increased with increasing altitude due to higher precipitation and lower temperature. The Century model estimated SOC stock with high accuracy. The defined scenarios for the Century model showed that climate change with reduced precipitation and increased temperature significantly decreased SOC stock. The negative effect of climate change was more pronounced at higher altitudes. Grazing also reduced SOC stock, especially at higher altitudes. In contrast, manure application increased SOC stock, and its positive effect was more pronounced at higher altitudes. In the climate change scenario with manure application, manure application largely compensated for the negative effect of climate change, but did not completely neutralize it. The results of this study indicate that soil organic carbon simulation models are accurate tools for predicting the effects of climate change, grazing, and manure application. In addition, the conservation of high- altitude forests and optimal forest management are of particular importance to prevent the loss of SOC stock and to combat climate change.