GM4.2Organic matter export across landscapes: Understanding the rates and controls
|Convener: R. Hilton|
Erosion can mobilise particulate organic matter (POM) from the landscape and contribute to the fluvial export of carbon and nutrients (e.g. N, P) from river catchments. If POM is derived from recent vegetation and soil, its erosion represents a lateral flux of atmospheric CO2, and if buried may contribute to CO2 sequestration. In contrast, erosion also liberates aged POM from soils and fossil POM from sedimentary bedrock. Oxidation of these materials may contribute CO2 to the contemporary system. POM export may also impact the nutrient status of the ecosystem from which it was eroded, influencing the cycling of carbon in vegetation and soil. Given the potential importance of physical erosion for organic carbon and nutrient transfer, we require improved constraint on the rates of POM transfer across landscapes and the processes which control POM export. This session calls for submissions which present new data on POM export at the catchment scale, and seek to provide process-based understanding on controls on the rates of POM transfer and variability in POM source. We are interested in contributions from catchments draining the full range of geomorphic, climatic and anthropogenic conditions. We also encourage studies which investigate the cycling and transformation of POM during its transport from the hillslope, through the fluvial system, and those quantifying the fate of terrestrial POM in depositional settings. Empirical and modelling studies of POM transfer are also welcomed.