Lignin depolymerization products as biomarkers of the organic matter sedimentary record in 210Pb-137Cs-dated lake sediments

A new lignin parameter, called delta (Δ), indicating the burden of lignin-derived organic matter deposited in sediments with mineral matter, shows changes between the uppermost and middle zones of the core. An increased ratio of vanillic acid (Ad) to vanillone (Al) in the uppermost sediment layers was noticed and attributed to the inflow of degraded organic matter washed out from the catchment area soil. Principal component and cluster analysis indicated the lignin load and quality as the main factors distinguishing the organic material in the core sections. Both the lignin load and quality gradients were in agreement with the lithology of the core, showing the steepest gradients at the boundaries of core sections deposited prior to/after the deforestation/afforestation events.