We review three intensive studies of soil C and N change in forests in and near Walker Branch Watershed, Tennessee, USA. Soils are similar in the three sites, but each has a different vegetation and site history (harvest followed by natural resprouting in mixed oak; Pinus taeda plantation and fertilization after clearing; and natural regeneration to mixed deciduous following abandonment from farm and woodland pasture). Soil C changes in two cases were unexpected large and the accompanying soil N changes could not be accounted for by any measured or known input or output. Potential sources of error, including the effects of coarse fragments, are discussed, and a new coring device is introduced that we believe will improve estimates of coarse fragments and reduced variability in soil sampling in soils with significant rock content.