Comparação florística e estrutural de ambientes inundados e não inundados em duas Unidades de Conservação na Amazônia Oriental.

Abstract

Ecological limitations make it difficult to identify patterns, shaping the composition and structure of communities through environmental pressures and biotic interactions, and understanding the ecological processes that influence species variation between habitats is a challenge in diversity distribution studies. The objective of this study was to carry out floristic and structural analysis in different physiognomies in the Amapá National Forest and the Caxiuanã National Forest in the Eastern Amazon, aiming to contribute to the conservation of the species. The research was conducted in two national forests (FLONAS): Amapá and Caxiuanã. In FLONA do Amapá, four plots of 1 ha were installed in each type of forest (Igapó, Terra Firme de Platô and Terra Firme de Baixio), totaling 12 ha. In the Caxiuanã FLONA, two plots of 1 ha were installed in each type of forest (Várzea, Igapó and Terra Firme de Platô), totaling 6 ha and life forms with DAP ≥ 10 were identified. The abundance of individuals and the number of species in the vegetation of the Amapá and Caxiuanã FLONAS were compared using the Mann-Whitney test or Simple Analysis of Variance. To compare the species composition between vegetation in the FLONAS, the Multivariate Dispersion Test (PERMDISP) and a Principal Coordinate Analysis (PCoA) were used to evaluate the grouping of samples. The analyses, based on Jaccard dissimilarity, were carried out in the R program using the Vegan and ggplot2 libraries. The composition and richness of species between types of physiognomies reflect the influence of historical factors and environmental filters in the formation of ecological niches where the upland and alluvial forest maintain rich biodiversity, with species adapted to specific conditions. The analysis revealed low dominance of the most abundant species in the plateau forests, reflecting the good state of conservation, while the floodplain forest in Caxiuanã highlights the importance of sustainable management of açaí and other species to avoid the loss of biodiversity.