STRUCTURE AND SPATIAL DISTRIBUTION OF Mimosa tenuiflora (Willd.) Poir. IN TWO CAATINGA FRAGMENTS IN PERNAMBUCO

Mimosa tenuiflora (Willd.) (jurema preta) is a xerophytic species of the shrub-arboreal habit, indicative of secondary succession stage of recovery or progressive, widely disseminated by different caatinga physiognomies of northeastern Brazil, bringing great potential. For the few studies that address their environmental performance, this study aimed to investigate structural and ecological aspects of its population, based data in diameter and height, and characterize the spatial distribution pattern of this species in the study areas. The phytosociological survey was conducted in two areas with 2 and 80 hectares of caatinga at the Experimental Station of Embrapa Semiarid, Petrolina - PE. 10 units were plotted on a random sample measuring 8.0 x 40 m, and included all individuals living in diameter at soil level >= 3 cm, and measured the total height of the same. Were sampled 283 and 61 individuals in 100 and 80% of plots in areas I and II respectively, inserted mostly in the first diameter classes (3.0 - 6.0 cm and 6.1 - 9.0 cm) and height (2.0 - 3.0 m and 3.1 - 4 m), without trend to standard reverse-J-shape in areas. The spatial distribution, measured by the Payandeh index, reached a value of 2.4 in area I and 7.8 in area II, indicating that the species has a aggregated distribution in both areas. The calculated values for the of Liocourt quotient in areas I and II respectively, got an average of 0.67 and 1.12 with great variation, showing unbalance, despite being in progressive process of natural regeneration.