“…Several other significant correlates to the NMDS ordination including silica (Si; R 2 = 0.45, p < 0.001), magnesium (Mg 2+ ; R 2 = 0.39, p < 0.001), potassium (K + ; R 2 = 0.37, p < 0.001), calcium (Ca 2+ ; R 2 = 0.23, p < 0.01), Cl − ( R 2 = 0.23, p < 0.01), sodium (Na + ; R 2 = 0.19, p < 0.01), and arsenic (As; R 2 = 0.18, p < 0.05) concentrations exhibited variation that was largely associated with differences in YNP and Iceland hot spring communities (Figure 3; Supplementary Figure 7). Again, such variation potentially reflects differences in high‐temperature water‐rock interactions that occur in the aquifers sourcing these springs that are hosted in rhyolitic (Si, Cl and As) or basaltic bedrock (Mg and Ca) (Arnórsson, 1995; McCleskey et al, 2022; Planer‐Friedrich et al, 2020).…”