This work describes the floristic composition in the future Cachoeira Porteira UHE-PA water reservoir area (located on the left margin of the Trombetas river), and the characterization of the vegetation. Data on abundance, dominance, frequency, Species Importance Value Indexes (IVIE), Family Importance Value Index (IVIF), and forest horizontal structure analysis, are presented in the present study. The studies developed in this work show the area's most important species and families, according to their influence on the forest structural profile definition, in addition to the identification of vegetation different types. The 13 surveyed forest hectares support 4.583 individuals, comprising trees, palms and lianas with DAP > 10cm, distributed in 359 species, 217 genera and 55 families (Three measures of ecological importance were totaled to give an Importance Value Index (IVIE) of the species). The two species with the highest IVIE, in all surveyed area, were Eschweilera coriacea (DC) S. A. Mori, with 15,24% and Micropholis guyanensis (A. DC) Pierre, with 10,87%. Families presenting the highest Importance Value Indexes (IVIF) in the 13 hectares, were Caealpiniaceae (31,45%) and Sapotaceae (30,34%).
Amazônia; forest tipology; forest inventory