Regional estimation of tropical secondary forest stages using optical satellite sensors

Secondary forests resulting from anthropogenic activity cover approximately 31% of the total closed forested land in tropical regions and represent a major sink for atmospheric carbon, particularly during the initial 30 years of regrowth. Regional estimates of secondary forest cover and hence the size of the associated carbon sink may be derived using NOAA AVHRR channels 2 and 3. Several younger regeneration stages may be described using AVHRR channels 1, 2 and 3. Secondary forests older than 30-40 years cannot be differentiated from primary forest. -Authors