Multi-temporal assessment of selective logging in the Brazilian Amazon using Landsat data

Large-scale selective logging is a relatively new activity in the Amazon and its full consequences have yet to be evaluated. Impacts by selective logging alone have been estimated to increase approximately 4-7% of the annual carbon release from deforestation. In this research, visual interpretation and semi-automated remote sensing techniques were applied to identify and map areas of selective logging in tropical terra firme (upland) forests together with the correlated multi-annual measurement results for 1992, 1996, and 1999, for the Brazilian Amazon. The research results indicate that selective logging is rapidly increasing in both intensity (regional) and area (basin-wide). By 1992, at least 5980 km(2) of forest had been logged. During the 1992-1996 and 1996-1999 periods the area impacted expanded by an additional 10 064 km(2), and 26 085 km(2), respectively. Selective logging within protected areas increased more than twofold between 1992 and 1996, and more than fivefold between 1996 and 1999 in that region. We also estimated that at least 3689 km2 had been actively logged in 1992, an additional 5107 km(2), and 11638 km(2), had been logged in 1996 and 1999, and at least 10% of total logged forests detected in 1999 were previously logged in the period of analysis.