Florística, estrutura e padrões de dispersão em um cerrado, Quartel Geral, MG

Abstract

This study was carried out at a Cerrado fragment of CAF-Santa Barbara enterprise, municipal district of Quartel Geral, Minas Gerais State, Brazil, located at 635m of altitude, 19o20’31” S latitude and 45o27’12” W longitude. With 400 hectares of Cerrado remnants with campo limpo, campo sujo and campo cerrado physiognomies, this fragment its limited in the north by Eucalyptus plantation of the enterprise, and in the south marginated by Córrego Fundo streamlet. The climate is Aw, tropical wet, with dry winter. The objectives of this work were to study out the floristic composition of woody component of a campo cerrado with influence of the Gallery Forest in the municipal district of Quartel Geral, Minas Gerais, Brazil; to study the woody structure of this cerrado, establishing the predominate phisiognomies; and to look for dispersion patterns of the woody component. The floristic composition and the phytosociological structure were obtained by plot method, delimiting an only plot, divided into 20 plots with 50 x 20 m, distributed in a continuous block of 200 x 100 m, making a total of 20.000 m 2 (2 ha). Every woody individual with circumference at soil level equal or above 10 cm was included, and the dead ones were included too. The total sample resulted in 1,311 individuals, 64 species, 45 genus and 26 families. As for floristic richness, the Malpighiaceae, Fabaceae, and Annonaceae, with 11, 5 and 4 species, respectively, were outstanding. Twelve families contributed with only one species. Malpighiaceae was the most representative (577), followed by Annonaceae (220). The Shannon (H’) diversity index was 2.827 and the Pielou (J’) equability was 0.675. The estimate of basal area was 10.69 m 2 /ha. The phytossociological parameters obtained, in terms of family, showed the dominance of the Malpighiaceae, followed by the Annonaceae, the Fabaceae, the Araliaceae, the Vochysiaceae, the Asteraceae, the Solanaceae, the Meliaceae, and the Erythroxylaceae. The Banisteriopsis anisandra obtained the highest value of importance index, followed by the Xylopia aromatica and Byrsonima crassifolia, Byrsonima sericea, Dimorphandra mollis, Stryphnodendron adstringens, Heteropteris byrsonimifolia, and Schefflera macrocarpa. Campo sujo and campo cerrado were the predominant physiognomies determined for the woody structure vegetation, obtained by calculation. For the dispersal patterns, based on Linear Regression, confirmed by Spearman’s correlation, there was a higher proportion of zoocoric woody individuals in most of the open parts, the opposite of the expected one, the non- zoocoric one. This relationship between woody individuals and zoocory contradicts the expected for open areas of the Cerrado, where the non-zoocoric dominates, and this may be explained by influence of the Gallery Forest of Córrego Fundo, because this pattern is found for forests.