Inventário Florístico e sensoriamento remoto de reserva legal em fragmentos de cerrado no sul do Piauí

Abstract

Contemporary period has been characterized by the accelerated pace of energy use and exploitation of natural resources that directly impact biomes, such as the Cerrado, one of the oldest and most threatened on the planet, which makes studies on its biodiversity extremely important. In this context, this research aimed to carry out a floristic inventory of specimens present in the Cerrado fragment located in the south of the state of Piauí, as well as to carry out the Normalized Difference Vegetation Index (NDVI) in the region to understand the behavior of vegetation under anthropic pressure. The area selected corresponds to the legal reserve of private property, which covers the municipalities of Sebastião Leal, Uruçuí, Landri Sales, and Antônio Almeida in the state of Piauí, in an area of Cerrado scrito senso. For the floristic inventory, 30 50m x 50m quadrants were allocated, sampling all individuals with a breast height circumference (BH) or base circumference ≥15 cm. The approach used to investigate vegetation cover was through the use of the Geographic Information System (GIS), with NDVI over 5 years (2019 - 2024), using images from the Landsat 8 and 9 satellites, and to analyze fire outbreaks in the study region from 2019 to 2023, the BD/Burns of the National Institute for Space Research (INPE) was used. The Floristic Inventory sampled 3540 individuals, belonging to 17 botanical families, distributed among 40 species. The samples collected were herborized and five were listed in the Rosa Mochel Herbarium. The diversity indices calculated were: Shannon-Weaver (H') with a figure of 2.48 nats.and-1, Simpson (D) equal to 0.84 and the Jentsch Mixture Coefficient (QM) scoring 1/76 (0.013). The average CAP was 38.57 cm and the average height was 4.28 m, in line with the Cerrado scrito sensu pattern. The NDVI recorded an average of 0.27 with a minimum of -0.11 and a maximum of 0.91 in 2019 and 2024 respectively. The data obtained from INPE showed that in 2019 there was a higher incidence of hotspots in the study area and 2020 the lowest. The vegetation studied had the potential to recover in response to the occurrence of accidents, maintaining its diversity. Still, the high incidence of fires is a serious environmental problem, disrupting the ecosystem and potentially causing the loss of local biodiversity. The study provides relevant information for building a panorama of the Cerrado and reveals the need for further studies.