Forest Fragmentation Dynamics in the Direct Influence Area of Iguaçu National Park, Brazil

Abstract

The landscape in the Gonçalves Dias river sub-basin is composed of the eastern portion of Iguaçu National Park and the agricultural matrix, inserted within its direct influence area. The sub-basin covers a priority area for biodiversity conservation and restoration in Paraná, as well as encompassing a strategic area for the formation of ecological corridors. We assessed the temporal dynamics of forest fragments in the eastern direct influence area of Iguaçu National Park and identified the predominant factors for the current landscape configuration. We used Geoprocessing techniques for the automatic delimitation of the sub-basin and Remote Sensing for the spatiotemporal analysis of Landsat images at 15-year intervals (1986, 2001, and 2016) to determine the history of land use and land cover changes. We obtained metrics and indices of the fragments composing the landscape of the agricultural matrix in 2016. Our spatiotemporal analysis revealed that the agricultural matrix was already fragmented in 1986 and that there was an increase in native forest cover during the analyzed period. We identified physical constraints for the implementation of agricultural activities, which were related to the native forest cover rate and its distribution. Of the 204 forest fragments identified in the landscape, 90% have an area below 50 ha. The fragmented landscape in the direct influence area of Iguaçu National Park was the result of the historical process of predominantly agricultural land use, guided by the few physical constraints of the relief.