Degraded forests in the Brazilian Amazon: Contrasting assessments from remote sensing data

Abstract:

Reducing Emissions from Deforestation and Forest Degradation (REDD) is an international effort to develop financial value for the carbon stored in forests. Degradation is the second “d” in “REDD” but in the Brazilian Amazon, the largest extent of tropical forest in any country on earth, it is still very poorly understood compared to the first “d”, deforestation. Forest degradation in the Amazon region of Brazil results primarily from logging and understory forest fires or from a combination of both processes. Current estimates based on remote sensing for the total area degraded vary by as much as a factor of four in a given year between 1999 and 2012. The total area of degraded forest and the effects of degradation on the reduction of forest aboveground biomass are probably less than for deforestation but no one knows how much less. I contrast case studies for four assessments of forest degradation area based on remote sensing data in the Brazilian Amazon and explain differences in the current assessments based on the process focus, temporal mismatches, the spatial scale of the analysis, and threshold effects.