The soil seed bank in under plantings of Eucalyptus grandis in the municipality of Brusque, Santa Catarina

Abstract

This study evaluated the soil seed bank in riparian environments occupied by plantings of Eucalyptus grandis W.Hill with different ages. The study area is located in municipality of Brusque, SC. Were collected at random 60 samples of 0.25 m² (14 m²) of the soil seed bank, in a depth of 0.10 m and disregarding the burlap layer. Those collections were done in areas with six, ten and 25 years of planting. Samples were discharged in trays and placed over workbenches without cover for seeds germination. It was sampled 4,894 germinated seeds distributed in 42 species, 33 genus and 18 families. The richest families were Cyperaceae (12 species), Poaceae (seven), Asteraceae and Rubiaceae (four each), with emphasis for the herbaceous life forms (34 species), shrubby (four), arboreal and climbing plant (two each). The species Cyperus sp. 2, Paspalum sp., Commelina sp., Phyllanthus niruri L. e Digitaria ciliaris (Retz.) Koeler presented the biggest number of germinated seeds at all environments. The greater species richness and diversity occurred in the younger planting, suggesting that the seeds germination of biggest number of species can be related to the bank seed activation, because of the high luminous intensity and to the entry of new seedlings during the planting reform. As a result of this research, it is concluded that the soil seed bank in plantings of E. grandis helps for the regeneration of herbaceous and shrubby species in the early stages of succession.