Methods to derive National scale soil horizon carbon stocks from the Scottish Soils Knowledge and Information Base (SSKIB)

This report outlines the methods used to derive the SSKIB_horizon_Cstock.xlsx dataset (Soil Survey of Scotland Staff. 2026. Scottish Soils Knowledge and Information Base (SSKIB_horizon_Cstock). James Hutton Institute, Aberdeen. Doi: 10.5281/zenodo.19203823). 

Briefly, to calculate the minimum, mean and maximum SOC stocks for each of the 3048 soil horizons held within SSKIB, the minimum, mean or maximum carbon concentration recorded in the SSKIB dataset was multiplied by the dry bulk density as predicted by random forest regression and the resulting carbon density was corrected for the proportion of stones within the horizon. By multiplying the carbon density by the thickness of the horizon, the horizon SOC stock was calculated.

Funding for this work comes from the Rural & Environment Science & Analytical Services Division of the Scottish Government including the Underpinning National Capacity fund.