This work assessed data from 32 forest sites in Rio de Janeiro and São Paulo, Brazil, using multivariate analysis to answer the question: Are there floristic patterns of the Atlantic Forest tree-shrub layer related to the Serra do Mar and the width of coastal plains in the states of Rio de Janeiro and São Paulo? Three multivariate analyses were performed to investigate the relationship between the tree-shrub flora and environmental variation in these 32 study areas. Our analyses demonstrated the influence of geo-climatic variation on floristic differentiation of tree and shrub species in Atlantic Forest regions generating groups of areas based on similar biotic and abiotic characteristics. These groups support the existence of floristic patterns within the states of São Paulo and Rio de Janeiro and reflect tree-shrub species substitution between the study areas as a consequence of annual rainfall, altitude, and mean annual temperature variation linked to a change in the position of the Serra do Mar and an increase in coastal plain width. Preferential species were cited for each group and should be considered in restoration and conservation programs for the phytoecological regions represented by the groups.
Atlantic rain forest; floristic composition; multivariate analyses; phytogeography
