Ecologia de uma Área de Carrasco no Domínio Cerrado: Estrutura e Relação Solo-Vegetação

Abstract

The present work intends to contribute with information about the ecology, floristic and structural diversity of carrasco vegetation that occurs in the Cerrado Domain in the state of Tocantins. In order to describe the floristic and structural diversity of carrasco vegetation, floristic and phytosociological surveys and soil-vegetation relationships were carried out. For the phytosociological survey, 50 plots of 10m x 10m were allocated, totaling 0.5 ha, where all trees and shrubs with a circumference ≥ 10 cm at the soil level and a minimum height of 1.0 m were sampled. For analysis of the phytosociological indexes, the parameters frequency, density, dominance and importance value were calculated. For Floristic diversity, the Shannon-Wiener indexes (H '), Pielou equability (J') were calculated for similarity between the Jaccard index plots and to verify the structural organization of the tree community, a Correspondence Analysis was performed DCA). For soil-vegetation analysis, five soil samples were collected at a depth of 0 to 20 cm in each plot, totaling 50 composite samples. The soil chemical and physical analyzes were carried out at the Soil Zoofértil Laboratory, in Palmas, TO. The physical parameters observed were the soil texture (sand, clay and silt) and chemical pH in KCl, P, K Ca, Mg, Al and Organic Matter (MO). The variables sum of bases, total cation exchange capacity (CTC), base saturation and aluminum saturation were calculated. Soil performance averages and phytosociological data were used to perform Canonical Correspondence Analysis (CCA). We sampled 4,110 individuals, distributed in 59 species, belonging to 37 genera and 22 botanical families. The ten most important species were: Manilkara triflora, Cordiera elliptica, Esenbeckia pumila, Myracrodruon urundeuva, Byrsonima coccolobifolia, Toulicia crassifolia, Buchenavia tetraphylla, Peltogyne confertiflora, Hymenaea eriogyne and Myrcia sp.1. The families that most contributed with the richness of species were: Fabaceae, Myrtaceae and Combretaceae. The soil is sandy, classified as Typical Orthotic Quartzeneic Neosol, and the environmental variables that most influenced the distribution of species and structural organization were Ca, K, CTC, pH and Al. The study was developed in two chapters. In the first chapter the ecology, floristic and structural diversity of the carrasco in Porto Nacional, Tocantins and the relationship between the soil attributes and the distribution of carrasco vegetation in Porto Nacional, Tocantins, were discusse.