Relationships between landscape structure and tree species diversity in tropical forests of South-East Brazil

This study sets up relations between spatial structure (i.e. landscape composition and physiognomy) and the diversity of vascular plants in a fragmented tropical area. The objective was to identify which parameters of landscape structure were more related with tree species diversity. The studied landscapes, located in the state of S o Paulo (S.E. Brazil), are characterized by a high degree of forest fragmentation owing to the expansion of coffee plantations in the second half of the 19th and the beginning of the 20th century. Eleven fragments of semideciduous forest were studied in the riparian corridor of the Jacaré-Pepira river. The neighbouring spatial structure and the tree species diversity of these fragments were evaluated and correlated. Forest connectivity (provided by forest corridors and matrix stepping stones) and landscape mosaic complexity (measured by boundary indices) were the main factors of spatial structure linked to the variations of tree species richness and evenness. These results suggest that the spatial arrangement of forest patches and the complexity of the matrix may be more important than the fragment area a]d isolation in controlling the survival of the studied species.