Estudo florístico da APA do Cariri, Paraíba, Brasil: Riqueza, similaridade e síndromes de dispersão

Abstract

The environmental conditions of an area influence in determining the structure and composition of local flora. Studies in the northeastern semiarid regions have shown a pronounced physiognomic and floristic heterogeneity. The objective of this study was to survey a stretch of the Cariri Environmental Protection Area (APA), semiarid region of Paraíba State, Brazil, and to verify the floristic similarity among other Caatinga areas of Northeast Brazil, as well as determine the life-form spectra and the dispersion syndromes of recorded species. During 15 months fertile specimens, containing fruits when possible, were collected and field observations were performed. One hundred seventy-seven species from 48 families and 125 genera of Angiosperms were recorded, also a Pteridophyta representative. Fabaceae (27), Asteraceae (10), Malvaceae and Poaceae (09), Cactaceae and Euphorbiaceae (08), Convolvulaceae andCyperaceae (07), Amaranthaceae and Bromeliaceae (06) were the richest families. The local flora found is more similar to a Caatinga area in the Pernambuco State. The dispersal syndromes of 77.7% of these species were determined, with a predominance of abiotic syndromes, represented by autochory (25.9%) and anemochory (28.3%), the zoochory represented 23.5% of syndromes; the remaining 22.3% could not be classified according to mode of dispersion. In the floristic spectrum there is a predominance of therophytes (27.7%), followed by small and medium-size phanerophytes (23.5%) and chamaephytes (22.3%), while hemicryptophytes and cryptophytes were represented by 9% and 0.6% respectively. The results obtained in this study are consistent with the literature data reported for other semiarid areas of Brazil.