A meta-analysis of carbon content and stocks in Technosols and identification of the main governing factors

Technosols, which are soils strongly impacted by human activity, are becoming increasingly common. To date, there has been little study of the share of the global soil carbon budget made up of carbon in Technosols or the contribution of Technosols to climate mitigation. A meta-analysis is proposed based on the analysis of 130 articles and consisting of the extraction of 953 observations on soil organic carbon (SOC) content of Technosols and related factors (e.g., climate, land use, nitrogen and bulk density). The mean SOC content of Technosols is 4.3% and SOC stock is 73.2 t C ha(-1) for the 0-30-cm layer. The SOC content does not decrease significantly with depth and it shows high variability, even within the same depth layers. Climate has a significant effect on SOC content, especially in the upper soil layer. Land use (mainly urban, mining or industrial) shows a significant effect when considering all depths and is related to the nature of the constitutive artefacts. Unlike natural and agricultural soils, no correlation is observed with the depth nor the nature and presence of vegetation. This meta-analysis highlights the strong originality and diversity of Technosols, compared to other soils. Compared to other existing Reference Soil Groups, they are undoubtedly among the soils with the highest carbon stocks per unit area in the pedosphere. Highlights Technosols appear to be among the soils with the largest organic carbon stocks Mean value of soil organic carbon content in Technosols is 4.3% As for natural soils, the soil organic carbon in Technosols is influenced by climate Artefacts appear to be a major driver of organic carbon in Technosols