Fig. 5: The impact of permafrost change on watershed carbon export.
From: Emerging dominance of summer rainfall driving High Arctic terrestrial-aquatic connectivity
The impact of localized active layer detachments (ALDs; geomorphological disturbance) on the relative contributions (%) of DOC and POC to the total annual fluvial C flux (2006-2017) in: (a) East river (ER; 1.2 % of watershed area disturbed); (b) West river (WR; 2.7% of watershed area disturbed); (c) Goose stream (GS; no geomorphological disturbance); (d) Ptarmigan stream (PT; 10.8% of watershed area disturbed). In geomorphologically undisturbed watersheds (a), the annual C flux is dominated by DOC; increasing mean annual DOC concentrations from these watersheds were likely the result of watershed greening. Thaw-induced geomorphological disturbance of terrestrial surfaces (a–b,d) decreased annual DOC concentrations at all watershed scales and led to a fundamental shift in the primary form of C export from a DOC- to a POC-dominated flux (p < 0.05), with the magnitude and persistence of impact increasing with areal extent of watershed disturbance.
