Phytosociology of the arboreal component in an area of Spring, Pernambuco

This study aimed to know the phytosociological composition of the arboreal component in an area of spring in Sirinhaém - PE. Ten plots (10 m x 25 m) were arranged in rays above the springs and distributed systematically in 5 lines, separated by a 45° angle, each. In each line, 2 plots were allocated, at an interdistance of 25 m. In each plot, all individuals with CAP ≥ 15 cm were sampled, which were measured and had the estimated height. The phytosociological parameters were analyzed and an admissible sampling error of 20% and probability level of 95% was adopted. The calculated sampling error was 18%, lower than that established. The spring had a density of 1,236 individuals ha-1, with an estimated basal area of 27,647 m2 ha-1. Tapirira guianensis was characterized by a combination of large numbers of individuals, high dominance and high frequency, demonstrating that it is a species with wide distribution in the area. Regarding the relative frequency, in addition to T. guianensis, Eschweilera ovata and Inga flagelliformis were distinguished. The highest values of absolute dominance were of the species T. guianensis and Virola gardneri. In terms of Importance Value, the highlight was on T. guianensis and V. gardneri