Florestas Estacionais Decíduas de Terras Baixas no Agreste da Paraíba, Brasil: Mata Atlântica, ecótono ou Caatinga?

Abstract

The Seasonal Lowland Forests (SLF) from the Paraíba state (Northeastern Brazil) have controversial floristic relationships, sometimes considered more related to the Atlantic Forest, sometimes to the Caatinga, or even as transition zone (ecotone). The present work aims to analyze the floristic relationships of the woody component among SLF in the Pre-Littoral Agreste of Paraíba, coastal Atlantic Forest, and the Caatinga. Twenty-two floristic surveys were selected, and analyses on Floristic Similarity and Parsimony Analysis of Endemism (PAE) were performed. Both analyzes revealed that the SLF form a group related to Caatinga s.l., not constituting an ecotone. The presence of elements of the Atlantic Forest on the SLF is marked especially by species widely distributed in forest ecosystems of Brazil. Higher rainfall and less marked seasonality in relation to the Caatinga s.s. may explain the occurrence of species typical of humid forests in the SLF.