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Natural regeneration is becoming more frequently used on a global level as a method of ecological restoration after mining operations. The objective of this study was to investigate forest restoration as a function of the exclusive use of natural regeneration in systems with two (NR2) and seven (NR7) years of age after bauxite mining in Eastern Amazon, Brazil (3° 14′ 51″–3° 15′ 48″ S and 47° 44′ 14″–47° 43′ 09″ W). Soil's physical and chemical parameters (organic matter, bulk density, porosity, infiltration, and fertility), landscape-level quantification of vegetation in the areas surrounding the study sites and attributes of the established vegetation (abundance of individuals and families, Shannon diversity index, evenness index, and ecological dominance index) were assessed. The method of natural regeneration, in seven years, was efficient to occupy and cover the soil by regenerating tree and shrub species, as well to contribute to the recovery of important surface-depth attributes of the quality of rebuilt soils, such as organic matter, nutrient availability, density, porosity, and water infiltration. The regenerating tree and shrub species had low diversity and high dominance of a few pioneer species, which indicates the necessity of introducing early and late secondary successional species to correct the successional trajectory in order to ensure the ecosystem restoration. [ABSTRACT FROM AUTHOR]

In the Eastern Amazon, abandoned and unproductive areas are widespread and normally found as a result of soil degradation. In this study we presented the following scientific question: Is it possible to improve the quality of soil physical and biological attributes of areas previously occupied by abandoned pastures with commercial plantation of the native species Dipteryx odorata ? To respond this question, the objective of this study was to evaluate the effects of D. odorata plantations after abandoned pastures on the soil physical and biological attributes, using the soil from a successional forest in the municipality of Óbidos, Eastern Amazon, Brazil, as a reference. Disturbed and undisturbed soil samples were collected from depths 0–10, 10–20, and 20–40 cm to determine organic matter content, bulk density, macro-, micro-, and total porosity. Soil macrofauna was collected at depth 0–10 cm and visual evaluation of soil structure was also conducted. The plantation accumulated organic matter and presented higher density of the macrofauna orders Haplotaxida and Blattodea, suborder Isoptera, and promoted better soil structural quality. Results were similar to those of the reference forest and higher than those of abandoned pastures. The D. odorata plantation was therefore an effective alternative for forest recovery of degraded areas in the region. • Dipteryx odorata improves physical and biological conditions of the soil • Dipteryx odorata plantation recovers soils of abandoned pastures • Soils attributes of Dipteryx odorata plantations resemble those of forest soils • Dipteryx odorata plantation can be recommended to recover degraded areas [ABSTRACT FROM AUTHOR]