Fig. 3
From: Bounding cross-shelf transport time and degradation in Siberian-Arctic land-ocean carbon transfer
Degradation rates and recalcitrant fractions for different terrOC pools. An exponential decay curve \(C\left( t \right) = C\left( 0 \right) \times {\mathrm{e}}^{ - kt} + R\) is fitted to measured loadings (filled symbols in a, c–f, error bars correspond to ± 1σ uncertainties) in surface sediments vs. transport time (calculated from the age-depth relationship, Fig. 2). Displayed curves (black lines in panels a, c–f) and uncertainty ranges of the fit (shaded area correspond to ± 2σ in panels a, c–f) for all parameters were determined by Monte Carlo simulations. The gray areas in panels a, c–f mark the positive offset \(C\left( {t \to \infty } \right) = R\), from which the recalcitrant fraction fR is calculated as \(f_{{\mathrm{R}}} = R/C\left( 0 \right)\). a TerrOC fraction of total organic carbon loadings as calculated with dual-carbon isotope source apportionment. b Comparison of the different first-order degradation rates k and recalcitrant fractions fR, derived in a, c–f. c–f Terrestrial biomarker loadings for the fine sediment fraction (<63 µm, see Methods section on bulk organic carbon and biomarker analyses and Supplementary Information Fig. 5 for details): lignin phenols (c), cutin acids (d), long-chain n-fatty acids (e), and long-chain n-alkanes (f)
