From homogeneous planting of Araucaria angustifolia (Bertol.) Kuntze to biodiverse forest, Capão Bonito, SP, Brazil

De plantio homogêneo de Araucaria angustifolia (Bertol.) Kuntze à floresta biodiversa, Capão Bonito, SP, Brasil

In the Araucaria Forest of the Capão Bonito National Forest, São Paulo, Brazil, we assessed floristics, phytosociology, vegetation typology, successional aspects, diversity, and similarity. In 65 plots of 10 × 20 m, data were collected for living tree individuals, considering the adult component (AC), individuals with circumference at breast height (CBH) ≥ 15 cm, and the juvenile component (JC), individuals with total height ≥ 1 m and CBH < 15 cm, recorded in 5 × 5 m subplots. For the AC, we registered 2,055 individuals, belonging to 51 families, 110 genera, and 198 species, with a density of 1,580.8 individuals·ha⁻¹ and a basal area of 40.3 m²·ha⁻¹. For the JC, 425 individuals were recorded, belonging to 32 families, 67 genera, and 111 species, with a density of 2,698.4 individuals·ha⁻¹. Shannon-Wiener diversity (H’) was 4.17 for the AC and 4.16 for the JC. Three families were dominant in both components: Myrtaceae, Lauraceae, and Fabaceae. The Jaccard similarity index between AC and JC was 0.45, and the Morisita-Horn index was 0.73. Six threatened species and two invasive alien species were identified. The typology of the Mixed Ombrophilous Forest (Araucaria Forest) was confirmed for the study site. Late secondary species predominated, accounting for 43.7% of all species. Floristic dissimilarity was observed between this study and others, as well as between the southern and northern portions of the Araucaria Forest in São Paulo State.

Keywords:
Biodiversity; Mixed Ombrophilous Forest; Plants succession; Similarity