Evaluation of LANDSAT images for monitoring forest management in the Amazon region, Brazil

In this study, it was evaluated the potential of LANDSAT ETM+ for detecting and monitoring the quality of forest management plans in the Brazilian Amazon based on the canopy disturbance in dense and transitional forests. The canopy disturbance dynamic was analyzed through vegetation fraction images obtained from spectral mixing analysis. These techniques were applied in areas of Conventional Logging (CL) and Managed Logging (ML) in two majors logging centers of the Amazon, Paragominas, in the northeastern Para State, and Sinop in northern Mato Grosso region. Hemispherical canopy photographs were taken at the management plots using "fish eyes" lens to quantify the canopy opening and to validate the satellites images measurements. The results showed that the vegetation fraction image was 4% less in ML (32 m(3)/ha extracted) and 12% less in CL (32 m(3)/ha extracted) relative to intact forest in the region of Paragominas; whereas in Sinop was 14% less in ML (35 m(3)/ha extracted) and 19% less in CL (34 m(3)/ha extracted). The method showed that canopy impacts can be detected at least one year after the logging activity. Therefore, this method can be an important tool for environmental agencies and institutes that provide forest certification to monitor the Brazilian Amazon forests undergoing logging activity.