Effects of Forest Restoration Techniques on Community Diversity and Aboveground Biomass on Area Affected by Mining Tailings in Mariana, Southeastern Brazil

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

Study on Site Preparation and Restoration Techniques for Forest Restoration in Mining Tailings of Mariana, Brazil

Ecological restoration in forest ecosystem is a priority in Mariana, Brazil. Thus, we evaluated the effects of passive and active restoration methods through different site preparation techniques by manipulating physical-chemical properties of substrates on tree community coverage in Mariana, Brazil. A total of 48 plots (12 × 12 m each) were established in two areas along the flood plains with accumulation of tailings. The following treatments were established: (1) planting of native tree seedlings with fertilization (PSf) and (2) without fertilization (PS); (3) direct seeding of native trees with fertilization (SDf) and (4) without fertilization (SD); (5) natural regeneration with fertilization (NRf) and (6) without fertilization (NR). Differences in substrate properties and tree community coverage were evaluated between treatments, the substrate properties and tree community coverage relationship, and main effects of substrate fertility and texture on tree community coverage. There were marked differences in substrate and plant coverage between treatments. On average, the highest plant coverage was found in treatment with fertilization, such as NRf (59,5%) and SDf (48%). However, the treatment with seedling planting (PSf and PS) and NR did not show differences (~37%), while the lowest values were observed in SD (23%). There is a strong relationship between substrate fertility and plant community coverage, with significant positive effects. We observed that the passive and active restoration methods can be complementary in the soil and plant community coverage recovery

Avaliação de nucleários como técnica de restauração florestal em Mariana, MG, Brasil

Este estudo teve como objetivo testar a eficiência do uso de um novo equipamento denominado nucleário, na sobrevivência e crescimento de mudas de espécies arbóreas visando à restauração florestal em áreas atingidas pelo rejeito da barragem de Fundão, em Mariana, MG. Foram avaliadas, por 12 meses, duas espécies arbóreas nativas (Piptadenia gonoacantha (Mart.) J.F. Macbr. e Inga edulis Mart.), sob um desenho de blocos aleatorizados e três tratamentos: hidrogel (T1), nucleário (T2) e controle (T3). Analisou-se o efeito dos tratamentos e do tempo após o plantio sobre a sobrevivência e crescimento das mudas, por comparação múltipla de médias e modelos lineares mistos. Foram observadas diferenças significativas de crescimento em altura e em diâmetro ao nível do solo (DNS) entre os tratamentos. As taxas de crescimento relativo para altura e DNS das duas espécies se mantiveram relativamente constantes, sem diferenças entre os tratamentos. Constatou-se que I. edulis apresentou sobrevivência maior na presença do nucleário, em comparação com os demais tratamentos. Os resultados indicam que apenas o uso de nucleários não foi suficiente para garantir o bom desenvolvimento e sobrevivência das mudas em campo, sendo recomendada sua avaliação para outras espécies arbóreas nativas