Agricultural terrace systems are the volumetrically largest, most common, and oldest artificial landforms. They have been implemented globally to allow cultivation of steep terrain and are among the most extensive anthropogenic landscapes, second only to urban areas. Terracing practices have introduced significant disturbances to topography, soils, and land use, but whether this results in soil organic carbon (SOC) sequestration or loss is uncertain and the underlying mechanisms driving differences in terraced SOC storage across climatic zones are unknown. These knowledge gaps hinder a scientifically based assessment of the role agricultural terracing could play in climate change mitigation.

I will present a study aiming to assess the size and development of SOC stocks of terraced landscapes across a broad climatic and geographical gradient in Europe. We integrated soil physical and geochemical properties, geomorphic features of terraces, soil age and climate to unravel how interacting geo-climatic factors govern the magnitude of terracing-driven SOC sequestration. We highlight the implications of our research for management of terraces to maximize their SOC sequestration potential.