Reforestation of riparian areas by direct seeding: the effects of sazonality, soil use, exclusion of predation, and depth on initial survival

Abstract

This study reports the effects of seasonality, depth of seeding, and predation exclusion on the early survival of Peltophorum dubium (Spreng.) Taub. and Enterolobium contortisiliquum (Vell.) Morong. seeds used to re-vegetate riparian areas. The study used proprieties along Guavira stream, in the west Parana region. Direct seeding was performed in the second week of spring, summer, autumn, and winter. Seeds were placed at the soil surface or at 2 cm depth. Predation exclusion was accomplish by a metal cage. The spring and summer seeding had survival rates of 36.6 % and 25.5 % in areas used for grain or pasture production and only 9.73 % for areas under forest patches when seeded at 2 cm depth. In general, during all seasons germinant survival was higher in altered areas than under forest patches.