Tree species distribution along soil catenas in a riverside semideciduous forest in southeastern Brazil

Summary The relationships between topography, soil taxonomic categories and tree species distribution were analysed in a riverside semideciduous forest on the margins of the Rio Grande, in Conquista, state of Minas Gerais, Southeastern Brazil. The forest was sampled by two transects made up of 50 contiguous 15 × 15 m2 quadrats (total 1.125 ha). Each transect started at the river margin and extended upslope so that they could include two soil catenas: the first with the sequence Ustifluvent, Haplustox and Ustorthent, and the second with Ustifluvent followed by Haplustult. A quick but more extensive survey was carried out in the whole forest fragment covering the same soil habitats in order to assess the extension of soil-species relationships found in the transects. A canonical correspondence analysis indicated that the species’ abundance distribution was significantly correlated with the soil habitats. Differences in soil drainage classes among the soils rather than their chemical properties appeared to be the leading factor: tree species distribution was strongly correlated with a wide hydrosequence ranging from poorly drained to strongly drained soils. The 55 most abundant species were classified according to their ecological group (regeneration guild) within the forest dynamics. A tentative ecological classification of those species combining their habitat preference in terms of soil drainage class and their growth strategy suggested that these factors play and important role in promoting the coexistence of tree species in that type of forest.