Fig. 2: Lignin oxidation product (LOP) ratios (S/V versus C/V) for speleothem samples and modern calcite.
From: Linked fire activity and climate whiplash in California during the early Holocene
Shown are speleothem samples with ages from 8.5 to 8.3 kiloyears before present (kyrs BP) (triangles), 8.2 to 7.8 kyrs BP (squares), and 7.7 to 7.0 kyrs BP (circles). The combined modern calcite samples are shown as an open diamond. The area shaded in dark brown corresponds to lignin originating from gymnosperm woody plants, as defined by Hedges and Mann29. The orange area is associated with gymnosperm non-woody plants, the purple area corresponds to angiosperm woody samples, and the pink area is associated with angiosperm non-woody plant parts. Error bars represent the standard deviation of samples measured in duplicate. The arrows highlight the changes over time. Plant icons available from phyloPic.org60 (lower left) and freesvg.org61 (others) and are licensed under Public Domain Dedication 1.062.
