Soil organic carbon stocks of afforested peatlands in Ireland

This paper quantified the soil organic carbon (SOC) concentration, bulk density, depth and carbon (C) stocks of 24 afforested peatlands. We found that the peat bulk density does not increase with depth, as has been previously noted in the literature. The depths of each different peat type were found to vary widely with means of 192 +/- 100, 145 +/- 130 and 127 +/- 100 cm for raised bogs (RB), high-level blanket bog (HLB) and low-level blanket bog (LLB), respectively. Based on the full-surveyed depth, we estimated carbon densities of: 1160 +/- 520 Mg C ha(-1) for RB peat; 775 +/- 590 Mg C ha(-1) for HLB peat and 705 +/- 420 Mg C ha(-1) for LLB peat. We found peat depth and peat type to be significant predictors of peat carbon density and present pedo-transfer functions for carbon density based on these predictors that will help to improve future peat C stock estimates. We suggest that due to the similarities between the carbon densities of the HLB and LLB, they can be analysed as one group for accounting purposes and future C stock estimates.