The objective of this work was to identify soil attributes and classes associated to the occurrence of forest and tropical savannah remnants in Campinas, SP, Brazil. Twenty seven native vegetation fragments were studied. Soil morphological, chemical, and physical characterization were carried out, along with floristic-phytosociological survey of the tree stratum. Canonic correspondence analysis identified variables better correlated with plant species distribution. Fifteen environment variables explained 31% of the variance of the first two axes. Soil classes at the Brazilian System of Soil Classification discriminated the studied vegetation: soils with argillic B horizons were more associated to forests, and soils with oxic B horizons, low fertility and good drainage were associated to tropical savannahs. Low fertility, low water retention and good drainage benefit cerrado vegetation establishment. Multivariate analysis identified n parameter of the water retention curve, bulk density, exchangeable H+Al, Ca, Al, K and Mg, macropores and soil organic matter as the most effective soil attributes to plant physiognomy differentiation. The chemical barrier imposed by excess aluminum and calcium deficiency, at B horizon, as well as low water retention in soils under savannah vegetation benefit Luehea grandiflora, Persea willdenovii, Xylopia aromatica and Erythroxylum daphnites, abundant and exclusive species on savannah fragments.
soil-vegetation associations; tropical savannah; soil water; aluminum toxicity
