Estudos de um banco de sementes no solo de um fragmento florestal com Araucaria Angustifolia no estado do Paraná

Abstract

Soil seed bank analysis in a forest fragment with Araucaria angustifolia, State of Parana. A research on soil seed bank had been developed in an Araucaria angustifolia (Bert.) O. Ktze. forest fragment in the State of Paraná. It had surveyed vertical distribution of seeds within the soil and shadow influence on seedling emergence, besides the improvement of their identification and quantity measuring. Vertical distribution of seeds in four soil layers had been analyzed by identification and quantification of germinated seedlings in greenhouse, with full light or 50% shaded conditions. Data related to seedlings of trees, weeds, grasses and lianas were calculated separately in weekly intervals during a 210-day period. Results suggested that the soil seed bank in this forest was poor in relation to tree species, in diversity as far as density. On the other hand, seeds of grasses and weeds decreased along vertical soil profile, and forest tree species tended to abundance in the 5-10 cm layer. Germination was higher with full light than in 50% shaded conditions. Probably, regeneration strategy for most species in this focused area doesn’t seem to be soil seed bank.