Search Results (3)

cangas are iron-rich outcrops where rupestrian fields develop in the Carajás Mountain Range (CMR). canga formations are ancient ecosystems characterized by high levels of endemic and threatened plant species that thrive on iron-rich substrates in the southeastern Amazon uplands. The recent taxonomic validation of these species enables more accurate distribution modeling across past, present, and future time scales. This work presents a comprehensive palynological database for the Amazon canga vegetation, resulting from extensive field and herbarium surveys, as well as the compilation and taxonomic validation of species in the Carajás Mountain Range (CMR). This atlas includes 204 plant species: 10 ferns and lycophytes, 62 monocots, and 132 eudicots and magnoliids (mainly herbs, lianas, and trees). Most flowering plants are pollinated by bees, with secondary pollination by other insects and wind. The taxa co-occur in two geoenvironments: (1) forested slopes and caves over plinthosols and ferralsols and (2) slopes with canga vegetation over plinthosols. Seventeen species are potential domesticates used by Indigenous peoples. This highlights canga vegetation as a unique and diverse ecosystem with various survival strategies, emphasizing the need for precise habitat definitions in paleoenvironmental and paleoclimate reconstructions. This atlas provides a valuable reference for palynological studies, enhancing the vegetation reconstruction, climate history analysis, pre-Columbian influences on vegetation patterns, and ecological monitoring. Full article

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. Full article

Fire is one of the most relevant ecological disturbances in nature. Little is known about the effects of fire on biodiversity in ecosystems like rupestrian grasslands, which share characteristics with savanna and forest biomes. Brazilian rupestrian grasslands are part of an endangered ecosystem that has been modified by anthropogenic fire events that have become more intense in recent decades. In this study, we evaluated the effects of fire on ground and arboreal ant assemblages through a two-year monitoring program (24 monthly samplings). We found that fire does not change cumulative species richness after 24 months, and that fire does not affect mean ant richness, abundance, and species composition in arboreal ants. On the other hand, fire increased mean ground ant species richness and abundance, and caused a significant change in species composition. Our results indicate a weak and beneficial effect of fire only for ground ant communities, which generally agrees with results from other studies in Brazilian savannas. Taken together, results from these studies may be useful for improvement of fire suppression policy in fire-prone habitats in Brazil. Full article