||Corvallis Environmental Research Lab., OR. ;Illinois Univ. at Urbana-Champaign. Dept. of Forestry. ;Woods Hole Research Center, MA. ;Wisniewski and Associates, Inc., Falls Church, VA. ;Trexler and Associates, Inc., Oak Grove, OR.
Forest systems cover more than 4.1 x 10(9) hectares of the Earth's land area. Globally, forest vegetation and soils contain about 1146 petagrams of carbon, with approximately 37 percent of this carbon in low-latitude forests, 14 percent in mid-latitudes, and 49 percent in high latitudes. Over two-thirds of the carbon in forest ecosystems is contained in soils and associated peat deposits. In 1990, deforestation in the low latitudes emitted 1.6 + or - 0.4 petagrams of carbon per year, whereas forest area expansion and growth in mid- and high-latitude forest sequestered 0.7 + or - 0.2 petagrams of carbon per year, for a net flux to the atmosphere of 0.9 + or - 0.4 petagrams per year. Slowing deforestation, combined with an increase in forestation and other management measures to improve forest ecosystem productivity, could conserve or sequester significant quantities of carbon.