Soil organic carbon is an important indicator for sustainable land-use, particularly in the tropics, and could play a role in climate change mitigation. While different tree species have been shown to be an important factor in changing soil carbon stocks following conversion of pastures to forest plantations in some situations, we found similar soil organic carbon (O horizon plus 0–45 cm mineral soil depth) beneath paired pasture and broadleaf plantation blocks and in paired broadleaf and conifer plantation blocks, with no significant correlation between aboveground biomass or stemwood productivity and soil carbon. Soil C differences between Pasture– Broadleaf pairs indicated a small decline in soil C accretion early after plantation establishment, followed by recovery to slightly higher accretion rates over the first 18 years of tree growth. However, no other significant differences in soil C dynamics between vegetation types were indicated over the time interval examined in this study. Neither forest plantation nor pasture soils appeared to reach the soil carbon levels present in the mature native forest under this time frame, which leads us to suppose the recovery of these eroded and disturbed soils may be a very long-term
process.