Floristic and structural variations of the arboreal community in relation to soil properities in the pandeiros river riparian forest, Minas Gerais, Brazil

Abstract

In the area comprised by the Brazilian semiarid is included the north of the Minas Gerais state, in the transition area between the Caatinga and Cerrado biomes. In this region distinct phyto-physiognomies are observed, basically making it a mosaic, with the occurrence of a wide variety of vegetal formations, such as the Restricted Sense Savanah, Seasonal Decidual Forests and riparian vegetation. This paper aims to present the structure of the shrubby-arboreal component of a section of the riparian vegetation of the Pandeiros river, Januária, Minas Gerais, Brazil, and to verify possible existent correlations between edaphic variables and the density distribution of species. Data was collected in 70 plots of 100m², in which five soil classes were found at the four sectors where 759 individuals, 31 families and 107 species were sampled. The most diverse families were Fabaceae, Malvaceae, Myrtaceae, Apocynaceae, Bignoniaceae and Combretaceae. The most abundant species were Hirtella gracilipes, Xylopia aromatica, Averrhoidium gardnerianum, Tapirira guianensis, Hymenaea eryogyne and Byrsonima pachyphylla. Hymenaea eryogyne, T. guianensis and Copaifera langsdorffii showed the highest importance values. The results suggest that, in addition to Ca, K, organic matter and flooding regime, which correlated with some species, the combination of the plots into three groups is also related to the sectors’ soil types. Thus, both the heterogeneity (provided by adjacent vegetation) and variety of soils and the flooding regime determine the formation of a unique riparian forest, with interactions between species that are characteristic of riparian forests, dry forests and savannah.