Afforestation effects on SOC in former cropland: oak and spruce chronosequences resampled after 13 years

摘要

Chronosequences are commonly used to assess soil organic carbon (SOC) sequestration after land-use change, but SOC dynamics predicted by this space-for-time substitution approach have rarely been validated by resampling. We conducted a combined chronosequence/resampling study in a former cropland area (Vestskoven) afforested with oak (Quercus robur) and Norway spruce (Picea abies) over the past 40 years. The aims of this study were (i) to compare present and previous chronosequence trends in forest floor and top mineral soil (0-25 cm) C stocks; (ii) to compare chronosequence estimates with current rates of C stock change based on resampling at the stand level; (iii) to estimate SOC changes in the subsoil (25-50 cm); and (iv) to assess the influence of two tree species on SOC dynamics.