Composição e estrutura da vegetação ripária na sub-bacia do córrego do Cintra (Botucatu–SP). Composition and structure of the riparian forest in the sub-watershed of Cintra stream (Botucatu–SP)

Abstract

As Cuestas Basálticas apresentam-se na paisagem da região central do Estado de São Paulo e caracterizam-se pela Floresta Estacional Semidecidual. O objetivo deste trabalho foi caracterizar a estrutura, estádio sucessional e a diversidade da mata ripária integrante da sub-bacia do córrego do Cintra, situada na região da Cuesta de Botucatu. O método fitossociológico utilizado em três áreas foi o de ponto-quadrante com dois indivíduos amostrados em cada quadrante e de tamanho > 5 m e 5 m and < 5 m of height. The Friedman test was adopted in the comparison among tree species in all three areas and was followed by Dunn’s test, at 5% significance. The analyzed indexes were relative dominance − (DoR), relative density − (DR), and covering index − (IVC), obtained by means of an electronic spreadsheet; the successional stage was determined by the relative proportion among the numbers of individuals of different synusiae species identified; and the diversity of species was studied based on the diversity indexes of Shannon-Wiener (H’), Pielou (J) and Simpson, connotation 1-D, using the software Past. In the three sampling areas, 2,241 arboreal individuals of 145 species were found, which belong to 55 botanical families, and the most representative families were Fabaceae, 16.3%; Lauraceae, Myrtaceae and Boraginaceae, 7% each, totaling 37.3% of the total sampling. The species with the highest DoR, DR and IVC in areas 1, 2 and 3, respectively, were Calophyllum brasiliense, Piptadenia gonoacantha and Gochnatia polymorpha. The successional stage in area 1 was considered late, in area 2 was intermediate, and the one in area 3 was pioneer, while the diversity (H’A1 = 4.08; H’A2 = 3.79; H’A3 = 3.31 nats/ind-1) of species was considered high and with good equitability for all 3 areas. Therefore, the indexes indicated greater dominance of a few species in area 3, which is in succession process, requiring reforestation and forest regeneration.

Keywords

• Mata Ripária
• florística
• estádio sucessional
• diversidade
• sub-bacia hidrográfica
• riparian forest
• floristics
• successional stage
• diversity
• catchment