Abstract

The objective of this study is to perform a phytosociological survey of the arboreous composition in conserved and desertified areas of the semiarid region of Paraiba State. Twenty-two conserved areas (CA) with native vegetation (Caatinga) where there has been no clear cut logging since 1984, and Twenty-two desertified areas (DA) having a difficult re-establishment of vegetal coverage over the past 10 years were selected. Plots with 100 m2 were established and the species were identified. The perimeter at 0.30 m ground level (PGL) and at breast height, 1.30 m (PBH) was measured. Subsequently, the absolute density (AD), relative density (RD), absolute frequency (AF), relative frequency (RF), absolute dominance (ADo), relative dominance (RDo), importance value index (IVI) and coverage value index (CVI) were calculated. There were 63 species of trees in CA and 9 in DA. The most frequent species were Caesalpinia pyramidalis and Croton sonderianus in CA, and Mimosa tenuiflora and Croton sonderianus in DA. CA showed an AD (4,845 I ha-1) higher than DA (895 I ha-1). The ADo order was C. pyramidalis > Anadenanthera colubrina > Myracrodruon urundeuva in CA, and M. tenuiflora > C. pyramidalis > Aspidosperma pyrifolium in DA. C. sonderianus (CA) and M. tenuiflora (DA) reached the highest IVI and CVI.

Key words: Caatinga, vegetation, biodiversity, environmental quality.