SSS7.6Movement and Fate of eroded soil organic matter in terrestrial ecosystems
|Convener: N. J. Kuhn | Co-Conveners: T. Quine , K. Van Oost|
The movement and fate of particulate Carbon mobilized during erosional events is one of the most poorly understood segments of the terrestrial carbon cycle and thus a major uncertainty for questions regarding for example the effect of agriculture on climate change. Key questions concern the selective detachment, transport and deposition of soil organic matter and its subsequent fate, i.e. permanent deposition or mineralization resulting in the release of greenhouse gases into the atmosphere. Movement and fate of eroded soil organic matter are strongly affected by the selective nature of soil erosion processes because both amount and quality of soil organic matter are not independent of particle size and sediment aggregation. Consequently, selective detachment, transport and deposition of either mineral soil particles or aggregates generate particular spatial patterns of landscape organic matter deposits and export to water bodies. Without understanding the spatial nature of soil organic matter erosion, deposition and export into aquatic systems, budgets estimating the net effect of soil erosion on climate cannot be established. A better understanding of the nature of soil organic matter behavior as a sediment and subsequent quality-controlled fate, is therefore required. This session seeks to attract contributions which deal both with (i) the processes determining soil organic matter erosion, in particular the amount and quality associated with different types of sediment, such as interrill and rill sediment, but also mineral particles or aggregates, as well as (ii) the amount and quality of the soil organic matter at erosional and depositional sites. Aim of the session is to connect researchers studying and modeling erosion processes with those examining archives of erosion and SOM deposition on a landscape scale. Bringing these two communities together will hopefully aid the development of a conceptual framework linking erosion processes to depositional features and the long-term effects of erosion on regional and global geochemical cycles.