Fig. 1: The concentration of plant-, microorganism- and fire-derived SOC components.
From: Climate warming and elevated CO2 alter peatland soil carbon sources and stability
Linear temperature response of the total sum of (a) solvent-extractable compounds (free lipids), (b) hydrolysable compounds (ester-bound lipids), (c) pyrogenic carbon and (d) lignin phenols in the surface peat (0–30 cm depth) following 4 years of warming and 2 years of elevated atmospheric CO2 concentrations. The concentrations are plotted against average soil temperature measured at 0.3 m below the hollow surface from 2016 to 2018. Colours represent ambient (orange) or elevated CO2 (blue) treatment (n = 5 per treatment). Symbols represent different sampling depths. Lines indicate significant treatment effects p < 0.05. Linear regression with 95% confidence intervals is shown in grey. The absence of a line and/or confidence intervals indicates no significant trend. Note that the concentrations in the deeper anaerobic peat (>40 cm depth) did not differ significantly with increasing temperatures (see Supplementary Fig. 5).
