Structural analysis of a forest in the Alto Paraná Ecoregion, Paraguay

Abstract

The Upper Parana Atlantic Forest has been included among the most diverse on the planet, not only characterized by its biodiversity but also by its high level of endemic species; however, due to the rapid growth of deforestation, it is also listed as one of the most threatened tropical forests in the world. In Paraguay, efforts are still needed in the ecological knowledge of this ecoregion. Therefore, the goal of this research was to analyze the horizontal and vertical structure of a forest of the Alto Paraná Ecoregion in a permanent plot (PPMB) with coordinates 25°30’35,41’’ S and 54°43’15,33’’ W. The structural parameters were: floristic composition, abundance, frequency, dominance, important value index, and vertical structure. In the permanent one-hectare plot (100 m x 100 m) were registered a total of 470 individuals belonging to 24 botanical families, 53 genera and 72 species. The results suggest that the forest studied is represented by Chrysophyllum gonocarpum (Mart. & Eichler) Engler with higher abundance, frequency and important value index. Furthermore, it is highlighted the presence of a greater number of individuals with heights less than 10,2 m (lower stratum) and mainly composed of pioneer species. The ecological parameters presented differences with the registered patterns at the regional level, which suggests that despite sharing biogeographic characteristics, there could be climatic, geological or other environmental and/or anthropic factors that influence the floristic composition and structure of the forest.