Key species selection for forest restoration after bauxite mining in the Eastern Amazon

Abstract

Bauxite mining has caused serious damage on local ecosystems and landscapes in the Eastern Amazon, Brazil. Considering these issues, the objectives of this study were to determine key species and their ecological characteristics that can contribute to forest restoration after bauxite mining. Key species are those with high frequency and abundance in different stages of vegetation succession. Data were obtained from forest inventories before forest slash down to extract bauxite and later subjected to factor analysis. The Phytosociological and Socioeconomic Index (PSI) was calculated with the following variables: abundance, frequency, dominance, live aerial biomass, commercial value of wood, and non-timber forest products of each species. The data comprised 24,600 individuals distributed in 462 species, 224 genera, and 62 families. Seventeen species, selected by PSI, were the most representative to restore areas after bauxite mining in the Eastern Amazon. The families with the highest richness were Lecytidaceae, Sapotaceae, and Fabaceae, representing 64.70% of the key species. Regarding abundance, the families Lecytidaceae, Urticaceae, and Fabaceae accounted for more than 75% of the individuals belonging to the key species. The 17 selected species belonged to the following ecological groups: late secondary (10), climax (5), initial secondary (1), and pioneer (1). The ecological knowledge of the selected species is important to plan and establish forest restoration projects, since ecological processes and functions can evolve n a more rapid and effective way.