LEVANTAMENTO FLORÍSTICO DO ESTRATO ARBUSTIVO-ARBÓREO EM ÁREAS CONTÍGUAS DE CAATINGA NO CARIRI PARAIBANO

The purpose of this research was to make a floristic survey of the shrubby-arboreous stratum in three contiguous areas of Caatinga in the Cariri of Paraiba. The survey was accomplished in the "Estação Experimental Bacia Escola/UFPB", municipality of São João do Cariri, PB Brazilian Northeast. The experiment consisted of three areas of 3.2 ha, where three parallel transects had been established, in a distance of 20 m from each other, and there were marked ten parcels with equidistant systematic distribution (10 m x 10 m), having been sampled 30 parcels from each area. The floristic survey was carried through by the method of parcels. There was fulfilled a grouping analysis using the index of similarity of Jaccard. The number of parcels showed was enough to reflect the plantdiversity of the studied places; the families with highest number of species in the arboreous-shrubby stratum were Cactaceae and Euphorbiaceae; the species that had been common in the three areas, , were: Aspidosperma pyrifolium, Croton blanchetianus, Poincianella pyramidalis, Jatropha mollisssima, Malva sp., Pilosocereus gounellei, Spondias tuberosa and Opuntia palmadora. The arboreous habitat presented seven species, being higher to the shrubby component that was presented with five species. The more conspicuous arboreous elements had been: Poincianella pyramidalis (Caesalpiniaceae) and Aspidosperma pyrifolium (Apocynaceae). The most important shrubs were: Croton blanchetianus and Jatropha mollisssima (Euphorbiaceae). The analysis made by the index of floristic similarity indicated that the similarity was considered high by the three area, because they presented a Jaccard index higher than 0.25.