Estrutura e composição da regeneração natural em um fragmento de Floresta Ombrófila Mista secundária

Abstract

Research on natural regeneration and its relationship with adult vegetation are important to subsidize the understanding of succession of secondary forests. The aims of this study was to characterize the ecological and floristic structure of the regenerative community (DHB < 5 cm) and its similarity to adult strata (DHB ≥ 5 cm), in a forest secondary Araucaria Forest fragment. Regeneration was sampled in 24 plots in three height classes and total natural regeneration (TNR) was calculated. We sampled 433 plants, belonging to 66 species and 29 botanical families, with emphasis on Myrtaceae. The floristic similarity between regeneration and the adult strata was high (68.3%). Regeneration and adult strata presented high diversity and equitability and low dominance. Allophylus edulis (9.5%), Mollinedia clavigera (8.5%) and Myrciaria tenella (8.3%) were the species which showed the highest TNR. They are typical of understory and they are not important in the adult strata. However, other important species in the regeneration, among them key species such as Ocotea porosa (Brazilian-walnut) should continue in the future structure of the forest. Most regeneration species are zoocoric and heliophilous, but the proportion of late stage species is higher in the larger size class, indicating that the forest is in full succession and evolving to its climax.