Estrutura e distribuição espacial de espécies de árvores gigantes na estação ecológica do Jari

Abstract

This study aimed to analyze the forest structure and spatial distribution of giant tree species in the Jari Ecological Station, located in the municipality of Laranjal do Jari, in the state of Amapá, bordering the state of Pará, in order to evaluate the five species with the highest importance value in the study area. Five permanent plots were established for sampling the arboreal vegetation. Five random permanent plots measuring 316 m × 316 m (9,98 hectares per plot) were installed, totaling 49,9 hectares analyzed across the five plots, considering trees with DAP ≥ 70 cm. A total of 529 individuals were recorded, distributed among 123 species and 30 botanical families in the five inventoried plots. The family Fabaceae showed the highest species richness, a pattern commonly observed in mature Amazonian forests. The species Dinizia excelsa Ducke, Qualea albiflora (Warm.), Huberodendendron swietenoides (Gleason) Ducke, and Goupia glabra Aubl. stood out from the other species by presenting the highest Importance Values (IV), totaling 160 cataloged individuals in the sampled area across the five plots, indicating a strong influence on local structure and dynamics. Analysis using the Morisita Index revealed an aggregated distribution pattern for the dominant species, suggesting ecological processes related to limited dispersal, concentrated regeneration, and environmental heterogeneity. Georeferencing of individuals made it possible to map the distribution of giant trees and identify potential conservation areas. We conclude that the Jari Ecological Station exhibits high floristic diversity and a structure typical of well-preserved primary forests.