Soil physical chemistry and tree species distribution in a basaltic cuesta region, Analândia, SP, Brazil

Abstract

Basaltic cuestas are located in the middle-west landscapes of São Paulo state. The goal of this study was to examine the influence of soil physical chemistry on the distribution of tree species populations in a basaltic cuesta toposequence. Data have been collected in a semideciduous forest fragment, in Fazenda Pedra Vermelha, Analândia municipality, SP (47°40’W, 22°08’S). Sampling has been done in 54 sampling units of 10 x 10 m, located in three different altitudinal quotas. Woody individuals with at least 1,3 m height have been collected and the chemical (macro and micronutrients) and physical (texture) analysis of the soil have been done. The percentage of the following soil components influence on species distribution: silt, thick sand, calcium, iron, organic matter, pH, CEC, sum of bases (SB), and base saturation (V%). On the lower quota, where the percentage of thick sand is higher and the levels of fertility are lower, the species Eugenia hiemalis Cambess., Chrysophyllum marginatum (Hook & Arn.) Radlk., Myrcia splendens (Sw) DC., can be highlighted. On the higher quota, where the percentage of clay is higher, and the levels of fertility are high the species Anadenanthera colubrina (Vell.) Brenan, Trichilia elegans A. Juss., Trichilia clausseni C.DC., have been collected. Thus, the results showed that beyond the nutritional availability influence on diversity, there are species that can be related to some edaphic characteristics, as well.