Impacts caused by the exotic invasion Megathyrsus maximus (Jacq.) B.K.Simon & S.W.L.Jacobs (Poaceae) on the vegetation of the atlantic forest

Abstract

The introduction of exotic species has led to the simplification of native biota, as well as causing various other negative effects on natural and man-made ecosystems. The process responsible for causing this problem is called biological invasion (BI). Among the species responsible for promoting BI is the grass Megathyrsus maximus (Jacq.) B.K.Simon & S.W.L.Jacobs. The aim of this study was to assess the impacts caused by the invasive exotic species on the composition, richness and diversity of the native vegetation of the Atlantic Rainforest. The work was carried out in the Serra de Itabaiana National Park, Sergipe. To assess the impacts, 40 1m² plots were plotted, half of which were installed in an invaded environment (AI) and the other half in an environment not invaded (ANI) by M. maximus. All herbaceous and semi-woody species were counted in these plots and statistical analyses (composition, richness, diversity and comparisons) were carried out using this data. We sampled 676 individuals distributed among 43 species in the IA and 943 individuals distributed among 90 species in the ANI. Diversity was 2.52 in AI and 3.83 in ANI. Similarity between the environments was 0.13 and dissimilarity was 0.18. According to the tests carried out, there are significant differences between the environments for all the variables tested. The results presented suggest that the presence of M. maximus causes changes in the composition and a decrease in the richness and diversity of native species in invaded environments. Public policies aimed at controlling the species are therefore suggested.

DOI:https://doi.org/10.56238/sevenIIImulti2023-173