Tracing ancient biomass burning using molecular biomarkers in marine and lake sediments

Biomass burning has played a significant role in determining the amount and composition of vegetation on land for at least hundreds of thousands of years. Furthermore, it is currently a major source of aerosol particles and CO2 which both have a large impact on climate. Reconstruction of past fire regimes have mainly relied on the analysis of charcoal or polycyclic aromatic hydrocarbons formed during biomass burning in ancient sediments.

Levoglucosan

Here we want to develop levoglucosan, one of the most dominant compounds formed during biomass burning, as a tracer for past burning events in marine and lake sediment records using a newly developed analytical HPLC-MSn technique. In this project we will further develop this technique to allow picogram amount analysis of levoglucosan, and associated anhydrosugars, in sediments.

Tracing burning events

We will trace the transport of levoglucosan through atmospheric dust and river transport as well as sedimentation through the water column to investigate how well sedimentary levoglucosan records reflect continental biomass burning events. Finally, we will generate levoglucosan sediment records together with molecular biomarker records for vegetation (distribution and isotopic composition of higher plant n-alkanes and triterpenoids), at different sites spanning a range of ages, to examine the effect of biomass burning on vegetation on land over geological time.

The development and application of this tracer for biomass burning will thus reveal new insights into the role of fire on vegetation changes on land.