Soil Seed Banks in Two Environments of Forest Restoration Post Bauxite Mining: Native Tree Plantation and Natural Regeneration

Abstract

The objective of this study was to compare the soil seed bank in an area under natural regeneration (F1) and another reforested through seedling planting (F2), seven years after bauxite mining, in Southeast, Brazil. In each area, 10 sampling points were randomly distributed, using three samples of topsoil to represent each point. The samples were transported to a shade house and evaluated for six months, where emerging individuals were identified every two weeks. Floristic similarity was evaluated with cluster analysis based on the Jaccard index (SJ). Species richness and abundance of individuals were compared using Student's t test. In F1, 2,114.94 propagules m-2 were registered, belonging to 51 species and 24 botanical families, Shannon-Wiener diversity index H’=2.770 and Pielou evenness index J’=0.705. In F2, 1,168.62 propagules m-2 were registered, belonging to 42 species and 22 families, H’=2.618 and J’=0.700. The (SJ) between F1 and F2 was 0.61, indicating a high similarity. The results showed high density of propagules, good diversity and absence of ecological dominance. The high number of individuals and diversity of tree species with zoochoric dispersion found in the areas indicates that both natural regeneration and reforestation were efficient in the ecological restoration of bauxite mined areas.