How much CO₂ can be sequestered by planting new hedgerows?

The establishment of hedgerows can be an effective climate change mitigation measure. If new hedgerows are planted, additional CO₂ can be sequestered in the growing biomass and in the soil underneath the hedgerows. As part of the CarboHedge project, 23 hedgerow sites were sampled across Germany to get more precise data on soil organic carbon storage underneath hedgerows compared with adjacent reference cropland. The sites differed in terms of hedgerow type, hedgerow age, soil type and climate at the site. On average, SOC stocks underneath the hedgerows were 29 ± 22 Mg ha^-1 (36 ± 49 %) higher than in the reference cropland (30 m away) in 0-100 cm soil depth; SOC stocks were not only increased in the topsoil but also in the subsoil. We also a found positive hedgerow effect on SOC stocks under the hedgerow edge and in the adjacent cropland (1 m away). The study shows the potential of hedgerow establishment for C storage not only in the biomass but also in the hedgerow soil and can be used to better quantify the C sequestration potential of new hedgerows.

https://doi.org/10.1016/j.geoderma.2024.116878