ABSTRACT
This chapter describes how organic carbon (C) is sequestered into different ecosystem pools, explains how it cycles among pools, and reviews some of the basic environmental forcing functions and management practices that alter pool sizes and rates of C cycling. The perspective is one of an ecosystem ecologist who is primarily interested in understanding the processes important in controlling C sequestration and cycling in forest soils. From a simple mass-balance perspective, all C transferred to the soil in living or dead biomass either resides in the soil, is lost out the bottom of the ecosystem as either dissolved organic or inorganic C, or is respired back to the atmosphere in the process of soil respiration. Soil C is the largest pool of belowground C in virtually every forest ecosystem. It accrues in the mineral soil over time and resides there in different and often complex organic forms.
