Figure 1.
Hierarchical cluster analysis of AMD samples
A. Hierarchical cluster analysis of environmental factors of AMD samples. Environmental factors including solution discharge rate (Flow, l/min), pH, temperature (Temp, °C), electrical conductivity (Cond, mS/cm), and the concentrations of ferrous (Fe2+, M)/ferric and ferrous (FeT, M)/ copper (Cu, mM)/arsenic (As, mM)/zinc (Zn, mM)/calcium (Ca, mM)/ sulfate (SO42−, M)/nitrate (NO3−, nM)/nitrite (NO2−, nM) were standardized before hierarchical clustered. The standardized values of environmental factors are color-coded in the heatmap, with larger values in red and smaller values in blue. B. Hierarchical cluster analysis of microbial community composition of AMD samples. A-plasma, E-plasma, G-plasma, and I-plasma represent Thermoplasmatales archaeon A-plasma, E-plasma, G-plasma and I-plasma, respectively; Lepto. group II, Lepto. group III, Ferro. type I, and Ferro. type II indicate Leptospirillum group II, Leptospirillum group III, Ferroplasma type I, and Ferroplasma type II, respectively. ARMAN2 are from the archaeal Richmond Mine acidophilic nanoorganisms (ARMAN) lineages. The results show that 17 samples could be classified into two groups. The group (S3/S4/S12/S13) with higher percentage of Leptospirillum group II is in the early developmental stage and the other group is in the late succession stage. AMD, acid mine drainage.