Seed rain and the establishment of seedlings in the tropical forest in the Northeast region of Brazil

Abstract

Mechanisms of natural regeneration are fundamental for ecological function restoration in forest fragments and degraded areas. The present work aimed to evaluate the seed rain and the establishment of seedlings of arboreal species in the Atlantic Forest, located in the northeast of Brazil. For sampling of the seed rain, 60 collectors were allocated (area of 0.196 m²), being equidistant, approximately, 50 m. The samples were collected at intervals of 30 days for a period of 12 months. To evaluate the establishment of seedlings, subplots were allocated next to the collectors, totaling 60 subplots of 0.25 m² each. The arboreal individuals identified by the diaspores collected in the seed rain and by the seedlings established in the fragment were counted and classified for the dispersion syndrome and successional group. The seed rain was represented by 60 morphospecies and 20 botanical families. The ecological group and the predominant dispersion syndrome were of early secondary and zoocoric species, respectively. In relation to the established seedlings, 122 seedlings were counted, being Tapirira guianensis L. with higher number of seedlings. The rainfall of seeds presents potential for the maintenance of the forest dynamics due to the high species richness that compose the current vegetation. Being predominantly composed of species that produce abundant fruits with zoocoric dispersion that serve as food for fauna. While few seeds germinate to form the seedling bank, most of them are contributing to seed bank formation.