Probabilidade de sucesso de espécies florestais na semeadura direta em restauração ecológica

Abstract

Among the large-scale techniques, direct seeding is seen as a promising low-cost and efficient methodology, but it requires improvement and, mainly, a selection of species that can be used at the beginning of the restoration. Thus, our objectives were (a) to identify forest species with potential for direct seeding in seasonal forest areas, (b) to investigate the behavior and survival of species over the studied period and (c) to classify species based on their probability of success and potential for direct seeding. In an area of 1.92 ha, direct planting of 38 forest species was implemented, in a system of groups of three rows with a density of 250,000 seeds.ha-1. The emergency was monitored over 720 days at different intervals and all individuals were identified and tagged in 160 plots of 3 x 1m. We count and measure the height (H) and the diameter at the height of the ground (DHS) for all seedlings. We classify species into classes of potentials based on their growth (H, DHS), germinability, emergency, and probability of success. Only 23 species emerged with a range of 3 to 241 individuals, with a total of 1520 plants and 1317 survivors after 720 days (13,718 individuals.ha-1). The emergence of Fabaceae family presented the highest richness (12 species) followed by Bignoniaceae (3 species). The highest heights were observed for the pioneer Mimosa bimucronata and the non-pioneer Astronium urundeuva. The selection of species promoted higher richness, diversity and density than traditional methodologies of direct seeding and the classification by potential allowed to determine the number of species established in the plantations and the number of seeds to be used by the restorer providing structure and coverage in the beginning of planting.