POTENCIAL DE BIOINDICAÇÃO DA POLUIÇÃO DO AR POR PLANTAS PRESENTES EM UM FRAGMENTO DE CERRADO

Abstract

Gas emissions from vehicles are the main source of air pollution in most urban centers and habitat fragmentation has exposed tree species to ever-increasing concentrations of atmospheric pollutants. The Cerrado is especially threatened by this type of environmental impact, as the low legal protection has resulted in extensive fragmentation, with consequent greater exposure of trees to sources of atmospheric pollution. This study aimed to evaluate the impact of proximity to sources of environmental pollution on the physiology of three plant species commonly found in Cerrado fragments. For this, sampling was carried out in a remnant of Cerrado in the municipality of Rio Verde, with two areas being selected in this remnant: area 1, located on the edge of the BR 0-60 highway and close to an industrial district; and area 2, located inside the fragment. In each area, three plant species were selected, with five replications each: Vochysia tucanorum, Tachigali vulgares, and Psidium oblongatum. At each point, the photosynthetically active radiation and soil moisture were analyzed to ensure that the species were in homogeneous conditions of light and water availability. The evaluations were carried out during the rainy season, in November 2021. Photosynthetic variables, the concentration of anthocyanins and flavonoids, nitrogen balance index, malondialdehyde concentration, activity of antioxidant enzymes, and species density were evaluated. Data were subjected to analysis of variance (ANOVA) and means were compared using the T test. Proximity to the highway decreased the photosynthetic rate of the plants, altered the concentration of anthocyanins and flavonoids, caused an imbalance in the nitrogen content and increased the occurrence of cellular damage, which, in turn, resulted in a decrease in the species density. These data point to the possibility of using the plant species evaluated here in environmental biomonitoring programs and demonstrate the risk of habitat fragmentation and anthropization for the conservation of Cerrado biodiversity.