Direct seeding in the restoration of post-mined campo rupestre : germination and establishment of 14 native species.

Abstract

Direct seeding in the restoration of degraded areas requires less financial investment and facilitates the use of greater diversity of species from different functional groups than traditional planting of seedlings. However, the application of this technique in the ecological restoration of post-mined areas in grassland environments is still poorly investigated. This study evaluated seed germination under controlled conditions, seedling establishment and associated costs of 14 species native to the Brazilian campos rupestres through direct seeding in a post-mined area. The effects of the incorporation of plant material (litter) to the degraded substrate on plant establishment were also measured. Under controlled conditions, 64% (9 out of 14) of the evaluated species showed germinability between 30 and 77%. Under field conditions, one year after, it was observed that the incorporation of plant litter to the substrate allowed the establishment of 49 individuals m− 2 of nine species, four of which with establishment percentage and cost per seedling of, respectively, 1.4–6.2% and US$ 0.006–0.09. In the other treatments, no significant plant establishment was observed. Despite the low percentage of establishment, direct seeding combined with the incorporation of plant litter to the substrate allowed the revegetation of a post-mined area with viable cost. The use of suitable species for direct seeding combined with techniques that promote improvements in substrate conditions is critical to increase establishment success using direct seeding in the ecological restoration of campos rupestres post-mined areas. Further studies on techniques to improve substrate quality and seed germination of native species of campos rupestres are required