Relação entre atributos do solo e a comunidade arbórea de uma floresta estacional no Rio Grande do Sul

Abstract

This study was conducted in a Seasonal Subtropical Forest remnant located in Itaara and belonging to the Plateau Border area of the Rio Grande do Sul State, Brazil. The aim was to analyze the pedological factors and verify their relationships with the physiognomy and community structure of the vegetation. We conducted a forest inventory in 23 plots of 200m² (20mx10 m) allocated over four transects systematically distributed 40 meters from each other. During the vegetation description, we recorded only the individuals of the arboreal and shrub stratum of the forest having diameter at breast height (DBH) ≥ 5cm. We performed the identification, DBH measurement and total height of the individuals, the vegetation canopy height, and the soil classification and morphological characterization in each plot. The sampling was composed by 944 arboreal individuals, which belong to 66 species and 32 families, in an area with estimated density of 2052 individuals ha-1. A grouping analysis applied to the recorded data separated the plots in four groups according their pH and soil depth similarities. The species distribution and vegetation structure were associated to soil characteristics, showing significant differences on canopy height and individuals total height among the different pedological groups. These results help to understand the relationship between the vegetation and the forest community substrate. Such knowledge is essential for planning the conservation of natural resources, environmental restoration, and for assessing the effectiveness of the management plans in other similar areas.