Carbon sequestration in hedgerow biomass and soil in the temperate climate zone

Hedgerows are a traditional form of agroforestry in the temperate climate zone. The establishment of hedgerows may be a promising strategy to promote carbon (C) sinks for climate change mitigation. We therefore conducted a meta-analysis compiling data from 83 sites on soil organic carbon (SOC) stocks beneath hedgerows in comparison with adjacent croplands and grasslands, plus biomass data from 64 hedgerows. On average (+/- SD), the establishment of hedgerows on cropland increased SOC stocks by 32 +/- 23 %. No significant differences were found between the SOC stocks of hedgerows and those of grassland. The average above-ground biomass stock was 47 +/- 29 Mg C ha(-1). Only one study reported measurements of below-ground biomass stocks and root/shoot ratios. Based on these measurements, an average below-ground biomass stock of 44 +/- 28 Mg C ha(-1) was estimated, but with high uncertainty. In total, hedgerows were estimated to store 104 +/- 42 Mg ha(-1) more C than croplands, with biomass contributing 84 % (87 +/- 40 Mg C ha(-1)) and soil 16 % (17 +/- 12 Mg C ha(-1)) to this amount. Total C sequestration with the establishment of hedgerows on cropland could be between 2.1 and 5.2 Mg ha(-1) year(-1) for a period of 50 and 20 years, respectively. Our results indicate that C stocks in hedgerows are on average comparable to estimates for forests. The establishment of hedgerows, especially on cropland, can therefore be an effective option for C sequestration in agricultural landscapes while enhancing biodiversity and soil protection.

Automated summary

Hedgerows are a traditional form of agroforestry in temperate climates and have potential for promoting carbon storage and climate change mitigation. Studies show that establishing hedgerows can significantly increase soil organic carbon storage, with no significant difference in carbon stocks between hedgerows and grasslands. Establishing hedgerows on cropland can effectively enhance carbon sequestration, while also enhancing biodiversity and soil protection.