Análise espaço-temporal dos fragmentos florestais do entorno de uma unidade de conservação na região norte do Paraná

Abstract

Forest fragmentation is a process in which continuous areas of vegetation are subdivided into smaller patches. In recent years, anthropogenic actions have intensified this process, causing several damages to the landscape’s natural components, as the loss of biodiversity. In this context, the mapping of forest fragments is presented as a subsidy to support environmental preservation actions. Therefore, the present work has the objective of performing a space-time analysis of the forest fragments found in both the Buffer Zone (BZ) and surrounding areas of the Mata dos Godoy State Park (MGSP), a conservation unit located in Londrina, Paraná. Therefore, an evaluation of the fragments’ spatial pattern was carried out for the years 1998, 2008 and 2018, by using landscape metrics, estimated from maps of land use and occupation. For the development of these maps and fragment distribution, techniques of classification of Remote Sensing images of the TM and OLI sensors were applied, respectively, on board the Landsat 5 and 8 satellites. The following categories of metrics were analyzed for the area of study through the Fragstats software: area and edge, shape, core area, and aggregation. The results indicated an increase of 16.88% in the total area of vegetation. As well as a consequence, the percentage of fragments in the landscape increased from 16.16% to 18.89%. The number of fragments decreased by 2257 due to their union, which resulted in an increase of the mean area in 5.4 ha and an increase in 0.103 of the irregularity of the spots measured by the average shape index. The percentage of vegetation under border effect increased from 40.2% to 37.1%. Isolation between fragments showed a decrease over the analyzed period. In 1998, the average distance euclidean nearest neighbor nistance distribution was 155.4 m, and in 2018, 149.7 m. However, this distance is still classified as a high degree of isolation, which affects the quality of fragments, for hindering the movement of organisms and the dispersion of species. Thus, all the analyzed metrics indicated a decrease in the degree of fragmentation in the study area, except for the edge density metric, in which its increase of 1.86 pointed to a lower degree of conservation during the analyzed period. A study of this nature is important since it provides subsidies for future researches on the management of forest fragments and can contribute to action strategies to be adopted in the Management Plan of the MGSP.