Programa de Pós-graduação em Ecologia e Recursos Naturias, Laboratório de Bioensaios e Modelagem Matemática, Departamento de Hidrobiologia, Universidade Federal de São Carlos - UFSCAR, São Carlos, SP, Brazil.
Laboratório de Fotólise, Fotocatálise e Especiação Química - LAFFEQ, Instituto de Ciência e Tecnologia - ICT, Universidade Federal de Alfenas - UNIFAL, Poços de Caldas, MG, Brazil.
Aquat Toxicol. 2020 Jul;224:105484. doi: 10.1016/j.aquatox.2020.105484. Epub 2020 Apr 27.
One of the consequences of global mining is the exposure of metals into the environment, caused by the rupture of tailings dams. Excess of metals, such as aluminum (Al) and manganese (Mn) can cause serious damage to fauna and flora. The presence of these metals, associated with the temperature increase that occurs nowadays can potentially increase biochemical and metabolic rates in plant tissues and may affect growth. Therefore, the objective of this work was to evaluate the toxicity of the metals Al and Mn into the biomass' growth of the macrophyte Ricciocarpos natans, under two temperatures (25 and 27 °C). R. natans individuals (n = 10 ± 0.5 cm wide) were exposed during 30 days to Al (1.5; 2.5 and 5.0 mg L) and Mn (0.7; 1.5 and 3.0 mg L) at temperatures and photoperiod-controlled germination chambers. Fresh macrophyte masses were determined gravimetrically to determine the kinetic growth using a logistic model. With that, it was noticed that the presence of Al interfered negatively in the increase of the R. natans biomass, mainly in the highest concentrations and at 27 °C. Mn, on the other hand, affected the increase in biomass, mainly in the highest concentration. As a result, the growth coefficients (μ) changed, being up to 4 times lower in the Al bioassays and up to 2 times higher than the control in the Mn bioassays. However, the dry R. natans biomass individuals that were exposed to the treatments was reduced when compared to the control, except for the lower concentration of Mn. These results contribute to the understanding of the environmental changes that can occur due to metals contained in mining tailings in aquatic ecosystems and the influence of global warming on the metabolic processes of the growth of aquatic macrophytes.
全球采矿的后果之一是尾矿坝破裂导致金属暴露到环境中。过量的金属，如铝（Al）和锰（Mn），会对动植物造成严重损害。这些金属的存在，加上现今发生的温度升高，可能会增加植物组织中的生化和代谢速率，并可能影响生长。因此，本工作的目的是评估金属 Al 和 Mn 在两种温度（25 和 27°C）下对大型水生植物 Ricciocarpos natans 生物量生长的毒性。将 R. natans 个体（n = 10 ± 0.5 cm 宽）在温度和光周期控制的发芽室中暴露于 Al（1.5；2.5 和 5.0 mg L）和 Mn（0.7；1.5 和 3.0 mg L）30 天。通过称重法测定新鲜大型水生植物的质量，使用逻辑模型确定动力学生长。结果表明，Al 的存在对 R. natans 生物量的增加产生了负面影响，主要是在最高浓度和 27°C 下。另一方面，Mn 会影响生物量的增加，主要是在最高浓度下。因此，生长系数（μ）发生了变化，Al 生物测定中的值低至对照的 4 倍，Mn 生物测定中的值高至对照的 2 倍。然而，与对照相比，暴露于处理的 R. natans 个体的干生物量减少，除了 Mn 的较低浓度。这些结果有助于理解由于水生态系统中采矿尾矿中所含金属以及全球变暖对水生大型植物生长代谢过程的影响而可能发生的环境变化。
