In negotiations over the Kyoto protocol and in other climate control discussions, U.S. representatives argued that the United States should be able to use its relative abundance of forests as "carbon-sinks" in order to offset higher levels of carbon pollution. The editors (three of whom are with the U.S. Department of Agriculture) present 25 chapters that discuss some of the basic science used to support that argument in relation to forest soils that contain an estimated 40 to 60 percent of stored carbons. The central topics addressed include the extent, general dynamics, and carbon dynamics of U.S. forest soils; soil processes and carbon dynamics; management impacts on U.S. forest soils; specific forest ecosystems; and synthesis and policy implications.