Seed Bank Taxonomic Diversity and Functional Composition in an Area Undergoing Forest Restoration in Brumadinho, Brazil

Abstract

Natural regeneration after mining activities largely depends on the soil seed bank. However, most seed bank studies have focused on the taxonomic composition variation of species and have yet to consider the relevance of functional composition based on categorical functional traits. For this reason, this research aimed to assess both the taxonomic and functional composition of the seed bank, evaluating the variation in regeneration strategies and dispersal syndromes in Brumadinho, Minas Gerais, southeastern Brazil. Three seed banks were sampled in the study area, one in the topsoil of the reference ecosystem (RE) and two in the Marco Zero area, the first site impacted by iron ore tailings reaching the Paraopeba River after a dam rupture. Samples collected in the MZ and MZM are the seed bank from the top 5 cm of the mud and the top 5 cm of the soil after the mud had been removed, respectively. The functional group composition showed significant differences when evaluating all seed banks in the study area. No difference was observed between dispersal syndromes after analyzing each seed bank’s functional composition by functional group separately. However, the differences among regeneration strategies in all seed banks were striking, mainly due to pioneer species. Although pioneer and anemochorous (wind dispersed) species are the two most dominant functional groups, comparing the functional composition between seed banks and regenerating vegetation and the contribution to ecosystem functioning is still necessary.