Forest fragmentation and its potential implications for the management of the Tarumã-Açu River basin, Central Amazon, Brazil

Abstract

The intensification of deforestation and the consequent fragmentation of the natural landscape in urban and periurban watersheds affect the entire eco-hydrological system, increasing the need to understand how these changes can affect their sustainability. In this sense, the present study evaluated the potential implications of forest fragmentation for the management of the Tarumã-Açu basin, based on the characterization of the structural and functional patterns of the landscape. For this, we mapped and categorized the basin’s forest fragments, based on the supervised classification (Bhattacharyya Method) of Landsat/OLI image, and, subsequently, we calculated the landscape metrics (area, density and size, edge, form, core, isolation and connectivity). The metrics showed a very fragmented landscape, especially in the region of the basin's low course, which concentrates the smallest, most dispersed, and vulnerable fragments even in conservation units. The headwater region, on the other hand, has the largest patches, with a large amount of central area and high structural and functional connectivity, which are fundamental for the sustainability of the basin and, therefore, deserve attention and prioritization by managers. The results offer important subsidies and unpublished data that can contribute to elaboration of the basin’s management plan and for the definition of conservation and restoration strategies of the forest remnants, indicating priority areas for the implementation of these actions.