Propagule emergence in topsoil from a high-altitude field and implications for bauxite mining area restoration

Abstract

The identification of factors that influence the timing of seedling emergence in topsoil is important to improve restoration strategies in former mining areas. The aim of this study was to determine the time of emergence of seedlings present in the topsoil of high fields in the Atlantic Forest on bauxite mines in the plateau region of Poços de Caldas, Minas Gerais, in both the dry and rainy seasons. The surface layer soil (top 5 cm) and litter were collected in August 2011 and March 2012. We collected 12 samples, consisting of 6 subsamples distributed in 3 sites (4 samples/site), from both the dry and wet periods (n = 24). The collected contents were placed in plastic trays and germination was evaluated in the greenhouse. The seedling emergence curve was adjusted. The values were submitted to analysis of variance associated with the Scott-Knott test (p < 0.05). The number of emerged seedlings and the time required for emergence to stop were lower in the rainy season than the dry season. The results show that the best time for the storage of the topsoil layer is the dry season, since it prolongs the viability of propagules and improves the success of recovery activities on mined areas.