Structure of a Prosopis juliflora (Sw.) DC. population established in a temporary riverbed in the Microregion of Cariri in the State of Paraiba Estrutura de uma população de Prosopis juliflora (Sw.) DC. estabelecida no leito de um rio temporário na Microrregião do Cariri Paraibano

The aim of this study was to evaluate the structure of a Prosopis juliflora population established in Serra Branca riverbed, in the Municipality of Sao Joao do Cariri, Paraiba . Nineteen months after the most recent flooding of the riverbed, 30 equally spaced transects were set up at a distance of 25 m apart from each other. Along the transects, 191 quadrant points were plotted (all at 5 m distance both from the river and from adjacent points), and 764 individuals of P. juliflora were sampled. The individuals that were closer to the intersection center of each quadrant point were surveyed, with measurements taken of the distance between them and to the point, their diameter at ground level (DGL), and total height. An average distance of 2.04 m was recorded between individuals (estimated density of 2,403 individuals ha -1 ), with the diameter ranging from 0.12 to 8.27 cm, and plant height from 0.01 to 3.0 m. The population of P. juliflora was composed predominantly of regenerating individuals, providing evidence that the occupation of the area by this invasive species was still in the early and middle stages of establishment. The results, in particular the rapid growth in diameter and height of young individuals, emphasized the ability of P. juliflora to occupy new niches, which ensures its competitive advantage in relation to native species.