ANÁLISE MULTITEMPORAL DA COBERTURA VEGETAL NA ESEC SERRA DAS ARARAS (MT) UTILIZANDO O ÍNDICE DE VEGETAÇÃO POR DIFERENÇA NORMALIZADA (1986 – 2025)

Abstract

Conservation Units are major pillars of in situ biodiversity preservation and, therefore, essential for the maintenance of ecosystem services (MEDEIROS; YOUNG, 2011; IPBES, 2019). According to Federal Law No. 9,985/2000 (SNUC), Art. 9, Ecological Stations are Conservation Units aimed at nature preservation and scientific research, where public visitation is prohibited except for educational purposes (BRASIL, 2000). Under this prerogative, the Serra das Araras Ecological Station contributes to the maintenance of the ecological integrity of the Cerrado (ICMBio, 2016). The present study analyzed the temporal dynamics of vegetation cover in the Serra das Araras Ecological Station, Mato Grosso, between 1986 and 2025, including a comparative evaluation between the Buffer Zone and the interior of the Conservation Unit. The methodology was based on the digital processing of images from the Landsat 5 satellite, referring to the year 1986 (USGS, 1986), and Landsat 8, referring to the year 2025 (USGS, 2025), with the application of the Normalized Difference Vegetation Index (ROUSE et al., 1973). From this procedure, vegetation cover maps of the conservation unit area and its surroundings were generated in a Geographic Information System (GIS) environment using the QGIS software (QGIS DEVELOPMENT TEAM, 2024). The results reveal significant changes in the landscape, mainly in the Buffer Zone, where Dense Vegetation underwent retraction, declining from 36.28% to 14.57% of the total area. Concurrently, an expressive expansion of the Grassland class was observed, which came to represent 54.81% of the landscape in 2025, in addition to a 16.87% increase in Exposed Soil areas. The individualized analysis of the interior of the Conservation Unit demonstrated a distinct behavior, with a less intense retraction of Dense Vegetation and a reduction in areas classified as Exposed Soil, indicating greater ecological stability when compared to the surroundings. The significant decrease in dense forest in the Buffer Zone, combined with the fragmentation of vegetation cover, highlights the intensification of anthropogenic pressures around the unit. However, the results indicate that, despite the recorded losses, the core of the Ecological Station still maintains significant portions of tree cover, suggesting that the unit has relatively fulfilled its environmental protection function in the face of the transformations occurring in its surroundings. The study reinforces the relevance of the integrated use of remote sensing and geoprocessing techniques as accessible and efficient tools for environmental monitoring in time series, supporting conservation actions and decision-making.