Uncertainty in peat volume and soil carbon estimated using ground-penetrating radar and probing

Estimating soil C stock in a peatland is highly dependent on accurate measurement of the peat volume. In this study, we evaluated the uncertainty in calculations of peat volume using high-resolution data to resolve the three-dimensional structure of a peat basin based on both direct (push probes) and indirect geophysical (ground-penetrating radar) measurements. We compared volumetric estimates from both approaches, accounting for potential sources of error, with values from the literature. Approximate uncertainty of 14 to 23% was observed in the basin volume, and the total uncertainty roughly doubled when incorporating peat properties to derive the estimated C pool. Uncertainties in final C stock values are based on the uncertainty of the basin volumes and the variability in the peat properties and range between 31 and 38%. The results indicate that the well-established ground-penetrating radar technique that is scalable to larger peatlands can be used to obtain estimates of peat basin volumes at uncertainty levels similar to those for invasive direct probe surveys. This investigation demonstrated that ground-penetrating radar can quantify peat basin volumes at uniquely high spatial resolution without the need for extensive and invasive direct probing.