Carbon cycling in a loblolly pine forest: Implications for the missing carbon sink and for the concept of soil
Understanding whether regional forests are net carbon (C) sources or sinks in relation to the global cycle can only be improved by better quantification of C dynamics in specific forests. This chapter examines the C cycle in a pine forest with special attention devoted to poorly characterized components and processes. A combination of loblolly pine allometric equations were used to estimate C in above- and below-ground biomass during the course of forest development. In order to estimate soil C changes, similar field and laboratory methods were used to collect and analyze soils in both 1962 and 1990. In both the three-decade study and in the chronosequence study, C in the coarse-textured mineral soil appears to reaccumulate slowly under pine. In the 6-m Ultisol profile, the C chemistry of the soil atmosphere and soil solution affects considerable acidification, largely from organic acids in surficial horizons and from carbonic acid in subsoils.
