Efeitos da proteção e do envigoramento na germinação e estabelecimento de plântulas de duas espécies arbóreas visando a semeadura direta

Abstract

Forested areas in climate mitigation has been recognized and the need for conservation and restoration became more evident. Several techniques have been studied in order to facilitate reforestation. In this sense, direct seeding techniques can be use in restoration project as a low cost alternative, however the success of this technique depends on favorable conditions for seed germination and seedling establishment. The aim of this study was to evaluate the effects of techniques that can be associated with direct seeding increasing the chance of success. Two different types of shields (metallic cages and bamboos) were used to evaluate the germination and establishment of Euterpe edulis Mart., a recalcitrant seeds species. In addition, other factors were evaluated as seed size, presence of wrappers fruit and seed position. Persistence of seed germination (%), seedling emergence (%), height and diameter of seedlings and recruitment were assessed in the first experiment and germination (%), seedling emergence (%), height and recruitment were evaluated for the second experiment. The exclusion of predation was not the most important factor in successful use of the seed, but the change microclimatic achieved with bamboo shields. For the other specie studied, Simira cf. glaziovii (Standl) Steyerm, one with non recalcitrant seeds, priming techniques were used to assess the viability and maintenance of germination for three months of storage. The treatments consisted of hydropriming and osmopriming and those with subsequent drying and storage. The control was also stored for evaluation. The results were favorable to either priming and storage after priming. This study shows that direct seeding can be a alternative to both species when used along with practices that favor the germination and establishment. The successful use of recalcitrant seed species depends on the creation of favorable weather conditions, which can be achieved with bamboo shields. For not recalcitrant species, the maintenance of seed viability during storage allows its use in times more favorable to germination.