Flora autóctone versus flora alóctone : uma avaliação diante do cenário das mudanças climáticas

Abstract

Climate pattern changes observed in recent years, together with the results of predictive climate analyses, point to a chaotic future for humans and global biodiversity. Therefore, the objective of the present study was to evaluate the biological differences and the carbon sequestration and storage capacity of Atlantic Forest environments with and without the presence of invasive alien species. The study was conducted in the Serra de Itabaiana National Park (PARNASI) in two distinct environments: (i) an Atlantic Forest area dominated by invasive alien species (IA); and (ii) an Atlantic Forest area without the presence of invasive alien species (NI). In each environment, ten permanent plots of 100 m2 were established. Within each sampling unit, all woody individuals with a diameter at breast height (DBH) ≥ 5 cm were recorded, and their DBH and total height were measured. These data were used to perform phytosociological and comparative analyses to evaluate differences between the environments. For soil carbon stock analysis, composite soil samples were collected at depths of 0–10 cm, 10–20 cm, and 20–30 cm. To estimate biomass, five litter collectors were installed in each environment, and all material deposited in them was collected every three months over a one-year period. A total of 265 individuals were sampled (NI: 121; IA: 144), distributed among 30 species (NI: 27; IA: 11) and 23 families (NI: 14; IA: 11). In the invaded environment, the species with the highest importance value was Syzygium cumini (RD = 40.15%), whereas in the non-invaded environment it was Handroanthus sp. (RD = 16.27%). Species diversity differed significantly between the environments (IA = 1.5; NI = 2.7; t = 6.5; p < 0.01), as did species composition. Notably, no species were shared between the two environments. Litter production and the concentrations of organic matter (OM) and carbon (C) in the soil and biomass did not differ significantly between the environments. The results indicate that invasive alien species do not affect carbon storage in the analyzed ecosystem components; however, they simplify the floristic composition, negatively impacting plant diversity by replacing taxa that are essential for maintaining local fauna and ecosystem services. Therefore, the conservation of forest remnants and the exclusive use of native species in climate change mitigation initiatives are recommended, ensuring equivalent efficiency in carbon sequestration and storage without compromising biodiversity through biological invasions.