Fig. 2: Greenness and soil properties along the gradient of snow cover duration.

a Landscape view of the upper part of the Roche Noire catchment taken on 2021-07-02. The foreground shows a mosaic of late-snow melting habitats, including sparsely vegetated sites on incipient soils (EA) and densely vegetated sites (CF) on well-developed soils. b Standardized Greenness Anomaly for the main habitats identified along the snow cover gradient (Methods, Fig. 1b). c Distribution of snow melt-out date (SMOD) and snow onset day (SOD) per habitat. Values were inferred from 43 sites in which near-surface soil temperature was continuously monitored since 2007. Each dot represents a site × year combination (n = 354). The horizontal lines show the distribution of observed SMOD and SOD values across habitats, including the median (solid) and the first and last deciles (dashed). d Topsoil (0–10 cm) soil organic carbon (SOC) content, e C:N ratio, f K₂O:TiO₂ ratio used as a proxy of mineral weathering. The comparison between the EA (n = 12) and non-EA (n = 33) habitats using a two-sided Wilcoxon rank-sum test is significant (P < 0.001) for all three soil properties. Boxplots within the violin plots show the median, first quartile, and third quartile of the distribution. Credit: a Ph. Choler, CNRS.