Figure 3: Distribution of 14C and 13C isotopes and end-member contributions across the fluvial network.
From: Utilization of ancient permafrost carbon in headwaters of Arctic fluvial networks

(a) Initial (open squares) and utilized (black circles) Δ14C and δ13C values of DOC. Isotopic ranges of three contributing carbon sources are shown in red boxes (see Methods). (b) Mean percent (±s.e.m.) contribution of each carbon source to the DOC utilized over bioincubations (DOCloss) in waters from differing site types.