Dinâmica espaço-temporal da vegetação secundária no município de Apuí (AM)

Secondary forests accounted for over one-third (266.000 km2) of the total deforested area in the Legal Amazon by 2008. This study analyzed the spatial and temporal dynamics of secondary forests in Apuí (AM), Brazil, municipality in which the expansion of cattle ranching has caused substantial increases in deforestation. A multi temporal series of 10 Landsat TM 5 satellite was classified by the maximum likelihood method in Envi 4.7 software. Mappings were analyzed by logical expressions using Dinamica EGO software, which allowed the extraction of information related to the land cover dynamics in the landscape. It also allowed the evaluation of the methodology employed in the images classification. The results pointed to the intensive land use system established in the region, where deforestation rates were above the average found in the whole Amazon in the last decade. The dynamics of secondary forest was associated temporally to the date of images acquisition and spatially to the local dynamics of pastures expansion and maintenance. The high land use dynamics in the region resulted in a high decrease of secondary forests; on average, only 10% of the secondary forests mapped in a year remain in the landscape after six years. The methodology employed in our study was useful for mapping land cover. The use of tools that allowed the overlay of classified images and the extraction of their quantitative information were essential to the refinement and analysis of data, minimizing errors associated with the process of classifying satellite imagery.Pages: 7639-764