Is forest restoration effective against climate change?

Soil Organic Carbon (SOC) is a key carbon reservoir and is highly sensitive to land-use changes, especially in sandy soils of humid tropical regions, where organic matter decomposition is accelerated and SOC stabilization is weak. In this context, forest restoration plays a key role in recovering carbon stock depletion caused by land-use changes. Well-planned restoration strategies can enhance carbon storage capacity, contributing to climate change mitigation. This study aimed to assess SOC stocks in Ultisols in southeastern Brazil, with a focus on forest restoration —an approach whose potential for SOC sequestration remains underexplored. Our hypothesis was that forest restoration would have a higher carbon sequestration potential than forest fragment due to the high plant growth activity associated with restoration efforts. We evaluated SOC stocks in coarse-textured Ultisols under forest restoration and preserved forest fragments in western São Paulo, Brazil, a region characterized by warm temperatures within the Atlantic Forest biome. Soil samples were collected to determine bulk density and SOC content at a depth of 1 meter. Overall, COS stocks were low and statistically different (58.5 and 51.5 Mg.ha in forest restoration and forest fragment, respectively) compared to soils from other Brazilian biomes with colder climates and finer textures. Preserved forest fragments exhibited better bulk density conditions throughout the soil profile, with a more stable structure. However, the restored areas had a statistically higher organic carbon content in most of the profile. This is because the developing vegetation ensures a continuous supply of litterfall, promoting greater carbon accumulation. In forest restored areas, soil showed signs of recovery. The comparison between these land-uses reinforces that forest restoration improves soil conditions over time, thereby reducing CO₂ emissions into the atmosphere. Forest restoration strategies focused on increasing deep soil carbon storage should be prioritized, particularly in warmer climates and sandy soils, contributing to the achievement of Sustainable Development Goals (SDGs) 2 and 13.