Estrutura populacional e espacial de Cereus jamacaru DC. Em duas áreas de caatinga do agreste da Paraíba, Brasil

Abstract

The native cacti still constitute a group of plants that require data in relation to its occurrence, distribution and dynamics with vegetation to subsidize management and conservation of families in the region. The aim of the study was to analyze the structure and the spatial distribution of Cereus jamacaru in a hypoxerophytic caatinga (In Campina Grande) and in a hyperxerophilic caatinga (In Monteiro) areas of semiarid of Paraíba state, Brazil. It had been plotted 200 parcels with 10mx10m in the municipalities of Campina Grande and Monteiro, PB state. In each parcel, all the individuals were sampled and labeled by measuring with the aid of tape measuring the base circumference of each specimen and height was earned with graduates PVC pipes. For evaluation of spatial structure, we obtained coordinates of each individuals, then, the maps of spatial distribution was produced. Thirty-nine 39 specimens were sampled in Campina Grande, showing basal area (BA) of 0.69 m2, absolute density (AD) of 39 ind. ha-1, the absolute frequency (AF) of 32% and a tendency to cluster (IGA = 1,01). In Monteiro, 38 individuals were sampled, AB = 0.47 m2, AD = 38 ind. ha-1, AF = 29% and a tendency to cluster (IGA = 1,11). The specimens of Cereus jamacaru showed clustering distribution pattern in the areas of secondary Caatinga, being that Monteiro’s population faces recruitment problems. Thus, it could imply in reproductive unsuccessful population future. The species shows similar distribution pattern in relation to other columnar cacti.