Tracing Fire-Derived Organic Carbon on a Global Scale

English Abstract:

Fire-derived carbon, is a persistent organic carbon fraction due to its aromatic nature (Wiedemeier et al., 2015). It is globally produced on large scales by biomass burning and by combustion of fossil fuel. As it is an inherently terrestrial product it has been investigated in soils and the atmosphere, then in rivers and oceans. However, different analytical approaches produced results which could not be compared directly, thus inhibiting the calculation of a combined global budget.

The question therefore remains: how much fire-derived carbon is produced, and then transported from terrestrial systems, through rivers to coastal and abyssal sediments? We need to exploit our analytical possibilities consistently on all environmental compartments in order to estimate integrated budgets.

In this presentation, we highlight the capabilities of a state-of-the-art molecular marker method (Wiedemeier et al., 2013, Gierga et al., 2014) to globally trace quantity, quality as well as ¹³C and ¹⁴C signals of fire-derived carbon. We show its use across small model lake systems, as well as major river systems of the world, e.g. to investigate size fractions of particulate suspended sediment. First results and important implications for the understanding of global carbon cycle will be discussed.

Wiedemeier, D.B. et al. 2015. Aromaticity and degree of aromatic condensation of char. Organic Geochemistry 78, 135-143.

Wiedemeier, D.B. 2013. Improved assessment of pyrogenic carbon quantity and quality in environmental samples by high-performance liquid chromatography. Journal of Chromatography A 1304, 246-250.

Gierga, M. et al. 2014. Purification of fire-derived markers for µg scale isotope analysis (δ¹³C, Δ¹⁴C) using high-performance liquid chromatography (HPLC). Organic Geochemistry 70, 1-9.