On a layer-by-layer basis, regressions of soil C in the O horizon and the 0–15 cm had no significant relationship over time. However, a slight decrease in mineral soil carbon stocks was noted in the pooled broadleaf and conifer plantations results in both the 15–30 cm (0.12 Mg C ha1 yr1) and in the 30–45 cm layer (0.08 Mg C ha1 yr1).