Herbaceous-shrub species composition, diversity and soil attributes in moist grassland, shrub grassland and savanna in Central Brazil

Abstract

The Cerrado biome comprises a mosaic of different vegetation types such as grasslands, savannas and forests. We studied soil properties and the herbaceous-shrub layer vegetation in moist grassland, shrub grassland and savanna. We assume that the moist grassland will present a distinct species composition from the other vegetation types, as waterlogging leads to changes in soil features that act as a filter of species that are adapted to this condition. The results showed that the soil in the moist grassland was distinct from the ones in savanna and shrub grassland. We found that the soil organic matter and the proportion of clay particles determined the variation in composition/cover and richness in the herbaceous-shrub layer in the three vegetation types. Higher organic matter content and smaller proportion of clay particles explained the larger distinction in richness and cover in moist grassland (lowest one) compared to shrub grassland and savanna sites. A total of 228 species in 47 families were sampled in the three vegetation types, and only five species were common to all three. The results revealed that, on a local scale, adjacent vegetation types of Cerrado with differences in soil organic matter and clay vary greatly in terms of growth forms, species composition and cover in the herbaceous-shrub layer. Understanding how herbaceous-shrub species richness and cover is related to soil nutrients, and texture heterogeneity in the mosaic of the vegetation types of the Cerrado may be useful in maintaining plant species structure and diversity.