Effects of Grazing Management Intensity on Carbon Stocks in Mediterranean Silvopastoral Systems

Agroecosystems integrate livestock and food production systems to meet global demands, but highly intensive management practices are often associated with soil degradation, erosion, and losses of soil carbon and biodiversity. In Mediterranean silvopastoral systems such as dehesas, grazing management plays a central role in regulating vegetation dynamics, nutrient cycling, and soil organic carbon storage. Understanding how different grazing intensities influence soil carbon stocks is therefore essential to support sustainable land management strategies in these systems.

This study examines the effects of contrasting grazing management intensities on soil carbon stocks and related soil properties within Mediterranean silvopastoral environments. Reforested areas without grazing were compared with two grazing systems characterized by different degrees of rotational intensity, allowing the evaluation of how grazing pressure and management strategies influence carbon distribution across ecosystem compartments. Field assessments to quantify aboveground and belowground carbon stocks included measurements of woody and herbaceous vegetation components, plant necromass, and soil carbon, with particular attention to spatial variability associated with tree canopy presence.

The results revealed consistent differences in soil carbon stocks among grazing management strategies, with lower grazing intensities generally associated with higher soil carbon accumulation compared to higher grazing intensity. The presence of grazing, when managed under rotational schemes, was linked to enhanced soil carbon stocks compared to unmanaged areas, suggesting positive interactions between livestock activity, vegetation turnover, and soil carbon accumulation. Tree canopy effects further influenced soil carbon distribution, highlighting the importance of spatial heterogeneity and vegetation structure in modulating soil carbon dynamics within silvopastoral systems. In addition, soil carbon stocks were closely associated with other indicators of soil fertility and nutrient cycling, reflecting broader changes in soil functioning linked to grazing management.

Acknowledgements

This work was funded by the project “Impact of grassland management on soil carbon storage-CARBOGRASS” (Project PCI2023-143386 funded by MCIN/AEI/ 10.13039/501100011033/EU).