Fig. 4: Trace gases and lithic compounds are major substrates that are differentially consumed across the chronosequences.

a Boxplots show nutrient concentrations across the Swiss (n = 15) and Antarctic (n = 9) glacier forelands, with measurements taken from three biological replicates per age group. Statistical differences among age groups for each nutrient were determined using two-sided ANOVA or the Kruskal-Wallis test. b, c Ex situ oxidation rates of sulphur (b) and nitrogen (c) species were measured in microcosm experiments containing 10 g of soil and 200 mL of ultrapure water, supplemented with 50 µM of ammonium chloride or sodium sulfide. Positive values indicate accumulation, while negative values indicate uptake. Measurements were performed with at least three biological replicates per age group. d Scatter plots illustrate in situ soil gas concentrations at Swiss sites relative to soil depth spanning ambient atmospheric conditions to deep subsoils (0−1 m). Linear models depicting significant relationships annotated with exact p-values and R² coefficients, with shaded ribbons showing 95% confidence intervals. e In situ soil–atmosphere gas fluxes of Swiss samples for each gas, with a minimum of three biological replicates per age group. f Bulk soil oxidation rates for each gas by soil age in Swiss samples, with different shapes indicating respective soil depths. Measurements were conducted on a minimum of five biological replicates per age group. g Bulk soil oxidation rates for each gas by soil age in Antarctic samples, measured with three biological replicates per age group. Box plots centre line represents the median, the box bounds denote the 25th and 75th percentiles, and the whiskers extend to the most extreme data points within 1.5 × the interquartile range.