In Brazil, the worst environmental disaster involving mining dams was the collapse of the Fundão tailing dam, in 2015. This accident affected directly the ecosystems of the regions surrounding the Doce River Basin. After continuous contamination of soils with heavy metals, only plants able to cope with the toxic effects of these elements can survive under this stressful environment. Thus, the main goal of this study was to carry out a detailed post-disaster analysis during two sampling periods to identify physiological and biochemical markers allowing us to understand the metabolic impact of heavy metals on Restinga herbaceous species. We determined the concentrations of heavy metals and antioxidant compounds, and further performed gas exchange analyses coupled with detailed biochemical analyses. These analyses were performed in two herbaceous species at seven Restinga stations along the coastal region of Espírito Santo - Brazil. The deposition of heavy metals such as iron and manganese varied considerably between the seven sampling stations and adaptive mechanisms to cope with excessive metals levels were verified in the herbaceous species. We observed several physiological and biochemical responses to metals that indicated potential adaptive mechanisms. Adjustments in the photosynthetic-related parameters including an acute reduction in stomatal conductance and transpiration rates associated with high stomatal resistance were noticed. Moreover, gradual reduction in pigments levels from the most distant stations to the ones closest to the Doce River mouth was noted in herbaceous species. Changes in the metabolism of nitrogen as protein content, carbon, and antioxidants were also noticed. Notably, variable responses according to the species and sample period demonstrate the further need for analysis over time to confirm the identified bioindicators.

在巴西，涉及采矿大坝的最严重环境灾难是 2015 年 Fundão 尾矿坝的倒塌。这次事故直接影响了多切河流域周边地区的生态系统。在土壤被重金属不断污染之后，只有能够应对这些元素的毒性作用的植物才能在这种压力环境下生存。因此，本研究的主要目标是在两个采样期间进行详细的灾后分析，以确定生理和生化标记，使我们能够了解重金属对 Restinga 草本物种的代谢影响。我们确定了重金属和抗氧化化合物的浓度，并进一步进行了气体交换分析和详细的生化分析。这些分析是在巴西圣埃斯皮里图沿海地区的七个 Restinga 站对两种草本植物进行的。七个采样站之间铁和锰等重金属的沉积差异很大，并且在草本物种中验证了应对过量金属水平的适应性机制。我们观察到对金属的几种生理和生化反应，表明潜在的适应机制。注意到光合作用相关参数的调整，包括与高气孔阻力相关的气孔导度和蒸腾速率的急剧下降。此外，在草本物种中注意到从最远的站点到最靠近多西河口的站点的色素水平逐渐降低。还注意到氮代谢作为蛋白质含量、碳和抗氧化剂的变化。值得注意的是，根据物种和采样周期的不同反应表明，随着时间的推移，需要进一步分析以确认已识别的生物指标。