SSS40

The molecular biogeochemical fate of terrestrial organic carbon
Convener: Klaas G.J. Nierop  | Co-Conveners: Boris Jansen , Ian D. Bull 
Oral Programme
 / Mon, 03 May, 13:30–15:00  / Room 1
Poster Programme
 / Attendance Mon, 03 May, 17:30–19:00  / Halls X/Y
This session will be devoted to the molecular characterization (including isotopic analysis) of organic matter in the terrestrial environment in order to improve our understanding of the abiotic and biotic processes responsible for the cycling of terrestrial carbon, relevant topics include:

- Soil formation and evolution
- Organic matter dynamics (i.e. transformation, diagenesis, preservation, sequestration),
- Reconstruction of past environments from soil and sediments (e.g.
paleo-environmental, archaeological)

All organisms contain unique combinations of organic compounds and as such, each provide a unique input of organic matter into soils and lacustrine/marine sediments both during the lifetime of an organism and after its demise. Whilst, under normal environmental conditions, a large proportion of this organic matter is rapidly degraded, a significant proportion of more persistent organic molecular and macromolecular components remain extant within the depositional environment. The input of organic matter into soils is a prerequisite for soil formation and as such the dynamics of organic matter transformation in soils plays a crucial role in pedogenesis. In addition, it also determines to what extent a soil
can function as a carbon sink or source over a relatively short period of time. Similarly, the burial of terrestrially derived organic matter in lacustrine and marine sediments is affected by abiotic (e.g. interactions with mineral surfaces) and biotic (e.g. methanogenesis) on longer time scales.

When organic molecules deposited into soils or sediments persist, either wholly or as a recognizable transformation product, they can serve as molecular proxies (or biomarkers) for identifying previous inputs of organic matter and various pedogenic processes stimulated by such inputs.
Furthermore, such biomarkers may serve as an aid to econstructions of paleo-vegetation and -climate and/or archaeological activities/land-use. At the same time the biogeochemical transformation of organic molecules helps elucidate past and present environmental conditions. All lines of research mentioned here share a common root in that they require a detailed characterisation of organic matter inputs and the transformation
products of such inputs at the molecular level. This session aims to provide a platform for research, which is both fundamental and applied, investigating any of the above themes but focusing on studies concerning discrete biomolecular components.