Floristic, structure and life forms of lower stratum in a alluvial dense rain forest, Pará state, Brazil

Abstract

The study aimed to describe the floristic composition and structure and life forms to lower stratum in a alluvial dense rain forest in the Environmental Protection Area of Combu Island, Belém, Pará state. Four plots were selected from 20 m x 20 m (0.16 ha) divided into 1.289 subplots of 1 m2. The size category and the life forms of the species were classified. Density, frequency, size category and natural regeneration relative were calculated. The difference in abundance, richness, Shannon index and evenness between categories was tested using ANOVA. All 33 families were found, 63 genera, 79 species and 26,885 individuals. Fabaceae, Araceae, Arecaceae, Acanthaceae and Meliaceae had higher richness. The Shannon index and Evenness were 2.63 and 0.60, respectively for the total area. Pariana campestris and Anthurium sinuatum showed higher density, size category and natural regeneration relative. Herb showed the highest percentage of individuals and natural relative regeneration and tree richest. CT1 (15 cm ≥ AT) was different from the other categories, with lower abundance and richness. It is concluded that the herb dominance in percentage of individuals and natural relative regeneration and the lower abundance and richness in CT1 is a consequence of the anthropic activities carried out such as the intensive management of açaí palm (Euterpe oleracea Mart.) In the vicinity of the inventoried areas.