Currently there is an urgent and special attention in actions to restore tropical forests. In this study, we evaluated the effect of different restoration methods on aboveground biomass (AGB) stock, tree community diversity and structure, in areas affected by the Fundão tailings dam collapse in Mariana, Minas Gerais state, Brazil. We measured and compiled data of the AGB, community diversity and structure attributes in 36 plots distributed in six restoration treatments and six replicas: planting of native tree seedlings with fertilization and pH correction (PSf) and without fertilization and pH correction (PS); seeding of native trees with fertilization and pH correction (SDf) and without fertilization and pH correction (SD); natural regeneration with fertilization and pH correction (NRf) and without fertilization and pH correction (NR). No significant differences in substrate properties and AGB between treatments. Although biomass storage between treatments was not statistically different, there is a clear pattern showing higher values active restoration method. The Pielou index ranged from 0.520 (SDf) to 0.943 (NR), except for SDf all the others treatments had values higher than 0.76. This result suggests floristic heterogeneity, without ecological dominance in the plant community. Overall, active restoration had important implications for the forest restoration where natural regeneration is limited.

The restoration methods applied on the areas affected by the Fundão tailings dam collapse have a high priority in Mariana region. We evaluated the effect of different restoration methods and site preparation techniques, depth and seasonality on penetration resistance of tailings, and how these predictors affect tree aboveground biomass in areas affected by the Fundão dam collapse in Mariana, Brazil. No significant differences in penetration resistance and aboveground biomass between treatments were observed, but significant differences were observed between seasonal periods.The main univariate model explained the significant effects of depth and seasonality, mainly by a negatively wet effect on penetration resistance. According to the best models (univariate and multivariate) were those that had depth as a predictor. This study showed how penetration resistance can be an indicator to select the best period for restoration process in areas affected by the collapse of the Fundão dam, but no limit to the aboveground biomass recovery on tailing.

The objective of the present study was to evaluate the influence of spacing, species richness, and sampling time on accumulated litter in forest restoration areas in the state of Espírito Santo, Brazil. The experiment was conducted under a randomized complete block design, in a subdivided plot scheme. Six treatments were evaluated, consisting of a combination of spacing levels and species richness. Accumulated litter samples were weighed and chemically analyzed to obtain nutrient concentrations. The variables analyzed in the restoration process, in general, did not influence litter biomass and nutrient concentrations. The time elapsed between restoration implantation and data sampling for the present study may have been insufficient for the occurrence of differences in variables evaluated. Despite the small amount of accumulated litter, it is of great importance for soil physical protection and fertility improvement, generating conditions for the stabilization of new forest species in the restoration area .

Functional composition is an important driver of aboveground biomass (AGB) variation in the tropical forest and has been demonstrated through the mass ratio hypotheses (MRH) that explain how dominant species and their functional traits have an important role in the AGB increase. We hypothesized that AGB stock of tree species is promoted by the simultaneous effects of restoration treatments and Technosol quality through functional trait composition. We tested the main effects of taxonomic, stand structural, functional attributes and abiotic factors undergoing different restoration methods (planting of nursery-grown seedlings, seeding, and natural regeneration) and the effect of Technosol fertilization on AGB using different linear models. The functional traits were based on the community-weighted mean of the community of values of functional traits related to MRH. Stems and biomass distribution were categorized into the following functional groups: successional strategy, dispersal syndrome, nitrogen fixation, wood density (WD). As expected, during early restoration stage, the pioneer and anemochoric species were dominants mainly represented by naturally regenerated stems. However, the autochoric dispersal and nitrogen-fixing tree species were biomass dominant groups in active restoration, driven mostly by Senna alata which had high abundance and WD. We found that high WD and active restoration methods determine higher AGB stock on mining tailings where natural regeneration is limited. We conclude that functional composition reverses the effects of species richness and abundance on AGB tenting the MRH. Therefore, the effects of functional composition and restoration methods are key predictors on ecosystem functioning during forest restoration.

Teor e redistribuição de nutrientes nas folhas de Bixa arborea Huber. e Joannesia princeps Vell. em área de restauração florestal Levels and redistribution of nutrientes in the leaves of Bixa arborea Huber. and Joannesia princeps Vell. in a florest restoration área