Carbon Pools and Flux of Global Forest Ecosystems

TLDR

Forests cover over 4.1 × 10⁹ ha and store ~1,146 Pg C, with roughly 37 % in low‑latitude, 14 % in mid‑latitude, and 49 % in high‑latitude forests, and about two‑thirds of this carbon residing in soils and peat. The study proposes that reducing deforestation and enhancing forestation and management could conserve or sequester substantial carbon, though future trends remain uncertain due to climate and land‑use change. In 1990, net forest emissions were ~0.9 Pg C yr⁻¹, and model projections indicate forests may act as either carbon sinks or sources in the future.

Abstract

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 at 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 +/- 0.4 petagrams of carbon per year, whereas forest area expansion and growth in mid- and high-latitude forest sequestered 0.7 +/- 0.2 petagrams of carbon per year, for a net flux to the atmosphere of 0.9 +/- 0.4 petagrams of carbon 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. Future forest carbon cycling trends attributable to losses and regrowth associated with global climate and land-use change are uncertain. Model projections and some results suggest that forests could be carbon sinks or sources in the future.