The revegetation of steep slopes after mining and infrastructure projects is not an easy task. To enhance the effectiveness of revegetation projects, the present study aimed to review (i) specific challenges of steep slope revegetation, (ii) ecological succession patterns in similar environments, (iii) soil conditioning and revegetation strategies to enhance vegetation cover, (iv) the importance of microorganisms to enhance steep slope revegetation, and (v) the functional plant traits necessary to establish on steep slopes. In general, steep slopes are characterized by high bulk densities, potentially toxic elements, and low water and nutrient availability. Additionally, high temperature and elevated radiation constrain the soil conditioning and vegetation cover establishment. Lessons from ecological succession in natural steep slope habitats show that steep slope revegetation is a long-term process. Planting strategies, including hydroseeding and geotextiles, may enhance the implementation of vegetation cover. Different plant functional groups show adaptations necessary for establishment in steep slope environments, and mixtures of species containing different functional groups can promote diverse and resilient plant communities. Promising species may be retrieved from local rupestrian ecosystems, as these floras are adapted to shallow, oligotrophic soils. Further research on combining methods of soil conditioning with individual planting and/or seeding strategies of carefully selected species is necessary to enhance steep slope revegetation and rehabilitation, contributing to slope stability, erosion reduction, and carbon fixation in the long term.

Lateritic duricrusts cover iron ore deposits and form spatially restricted, unique canga ecosystems endangered by mining. Iron cycling, i.e., the dissolution and subsequent precipitation of iron, is able to restitute canga duricrusts, generating new habitats for endangered biota in post-mining landscapes. As iron-reducing bacteria can accelerate this iron cycling, we aim to retrieve microbial enrichment cultures suitable to mediate the large-scale restoration of cangas. For that, we collected water and sediment samples from the Carajás National Forest and cultivated the iron-reducing microorganisms therein using a specific medium. We measured the potential to reduce iron using ferrozine assays, growth rate and metabolic activity. Six out of seven enrichment cultures effectively reduced iron, showing that different environments harbor iron-reducing bacteria. The most promising enrichment cultures were obtained from environments with repeated flooding and drying cycles, i.e., periodically inundated grasslands and a plateau of an iron mining waste pile characterized by frequent soaking. Selected enrichment cultures contained iron-reducing and fermenting bacteria, such as Serratia and Enterobacter. We found higher iron-reducing potential in enrichment cultures with a higher cell density and microorganism diversity. The obtained enrichment cultures should be tested for canga restoration to generate benefits for biodiversity and contribute to more sustainable iron mining in the region.