We investigated key ecophysiological traits of microbial communities across different disturbance levels for two upper horizon depths (A1: 0–3 cm and A2: 10–13 cm) in areas disturbed by Fundão dam failure across Gualaxo do Norte river. We found that lower microbial growth (microbial biomass) and higher microbial-C losses (high qCO₂) were linked to both decreases in organic substrate availability and enzyme activity suggesting important feedbacks on C dynamics in areas disturbed by Fundão dam failure. Basal respiration was not affected by organic substrate availability but increased with enzyme activity at A2 suggesting an enzymatic compensation in response to a lower plant-derived input. Lower degradative activity of extracellular enzymes (expressed as GMean index) was linked to lower organic matter content in mine tailings. Our results suggest that changes in organic substrate availability reflect changes in the microbial-controlled C dynamics in mine tailings. Thus, the design of restorative strategies based on microbial traits has the potential to accelerate the rehabilitation in areas disturbed by Fundão dam failure.

我们在北瓜拉索河上因 Fundão 大坝溃决而受到干扰的地区调查了不同干扰水平下微生物群落的关键生态生理特征，其中两个上层深度（A1：0-3 厘米和 A2：10-13 厘米）。我们发现较低的微生物生长（微生物生物量）和较高的微生物碳损失（高q CO ₂) 与有机底物可用性和酶活性的降低有关，这表明在受 Fundão 大坝破坏影响的区域中，对 C 动态的重要反馈。基础呼吸不受有机底物可用性的影响，但随着 A2 酶活性的增加而增加，表明对较低的植物来源输入的酶补偿。胞外酶的较低降解活性（表示为 GMean 指数）与尾矿中较低的有机物含量有关。我们的结果表明，有机底物可用性的变化反映了尾矿中微生物控制的 C 动力学的变化。因此，基于微生物特征的恢复策略设计有可能加速受 Fundão 大坝破坏影响的地区的恢复。