Natural regeneration in a mixed ombrophilous forest remnant in southern Brazil

The study of forest regeneration allows the diagnosis of conservation status of fragments and estimating population parameters that are essential for management projects. This study evaluated the structure, diversity and dynamics of the tree regenerating component of a remnant of mixed ombrophilous forest, aiming to support management actions for this forest type. The study was developed at the Parque Estadual das Araucárias (PEAR), located in the western region of the state of Santa Catarina, southern Brazil. A total of 100 plots of 25 m2 (0.25 ha) were allocated, all individuals with height ≥ 1.0 m and DBH < 5 cm were sampled. Shannon’s diversity index (H’), Pielou’s equability index (J) and total natural regeneration rate (TNR) were estimated. We sampled 1,425 individuals from 99 species and 39 families, with an estimated total density of 5,700 individuals by hectare. The richest families were Fabaceae (13), Myrtaceae (10) and Lauraceae (7). The H’ was 3.76 and the J was 0.80. The TNR rate ranged from 0.05 to 8.12%, highlighting Trichilia elegans, with the highest rate and Araucaria angustifolia with low potential for natural regeneration. The analysis of the results indicated a high diversity in the regenerating component of the PEAR compared to other studies, probably because the area presents itself as a successional mosaic due to past disturbances.