Abstract
The humid tropics play an important but ambiguous role in the global carbon cycle. While deforestation has been estimated to release about 1.6 Gt C y-¹ (HOUGHTON, 2000), mature Amazon rainforests appear to sequester carbon (act as a sink), but of an uncertain magnitude. Current estimates of sequestration have wide variation between different types of measurements, ~1,3 Mg C.ha-¹ yr-¹ base…