Diversity, abundance and distribution of lianas of the Cerrado–Amazonian forest transition, Brazil

Abstract

Background: Lianas strongly influence tropical forest dynamics and diversity. Aims: To determine the relationship among richness, diversity, abundance and distribution of liana species in different vegetation formation types along a gradient within a savanna–forest transition zone in central Brazil. Methods: All liana species were identified and their girth measurements (≥5 cm) taken in one 1 ha plot at each of 15 sites that encompassed a range of vegetation types: dystrophic cerradão (tall closed woodland cerrado), gallery forest, flooded forest, semi-deciduous seasonal forest (one monodominant) and evergreen forest. We evaluated and compared the communities in terms of richness, community diversity (Shannon's H’), equitability (Hurlbert's, PIE), and the distribution of liana abundance. Results: In total, 1467 individual lianas belonging to 65 species, 41 genera and 17 families were recorded in the 15 ha sampled. The value of H’ varied from 0–2.47, and that of PIE ranged from 0–0.90. While flooded forests had remarkably high liana densities, their liana community was dominated by just one species, Combretum laxum (64% of stems); the most abundant liana in non-flooded forests was Heteropterys eglandulosa (13%). The different liana species showed varying affiliations with vegetation type, with distinct species groupings associated with the different vegetation types. Conclusions: Variations in species composition and distribution of lianas in this savanna–forest transition were found to be driven by environmental gradients that cause distinct species associations with discrete vegetation formation types.