ABSTRACT
This chapter aims to develop an inventory of the organic carbon (C) held in forested soils of the United States and Puerto Rico based on available data. The spatial patterns and total amounts of soil organic C (SOC) in forests of the United States and Puerto Rico were determined using moderately detailed digital soil-survey data linked to a large national soil-characterization database using soil classification. The amount of SOC held in mineral soils and organic soils is dramatically different. Consequently, it is important to distinguish these two distinct kinds of soils to more accurately estimate the amount of SOC held by each forest-type group. The calculation of total SOC held in each forest-type group is the product of the area of each kind of soil and the carbon content of that specific kind of soil. Developments in soil taxonomy have changed most great-group names that indicate high amounts of organic matter to subgroup names.
