Pyrolysis GC-MS as a rapid screening tool for determination of peat-forming plant composition in cores from ombrotrophic peat

► Analytical tool to rapidly screen peat archives to determine vegetation input explored. ► Confirmation of Sphagnum pyrolysate biomarker 4-isopropenylphenol (from sphagnum acid). ► Ratio of 4-isopropenylphenol and lignin (“I%”) tested as a Sphagnum macrofossil proxy. ► Macrofossil decay affects sphagnum acid; other markers quantify original sphagnum input.