Description
Peat-filled valley systems are characterized by a lack of clastic sediment, having most of the valley filled with organic material. These systems provide a wide range of ecosystem services, such as a carbon sink, floodwater retention, drought resilience and enhance biodiversity. It is clear that chances for peat growth and preservation strongly depend on stream morphodynamics. However, there is a lack of quantitative understanding of peat stream morphodynamics, as peat streams functioning differs from that of alluvial streams. In this study we quantify peat stream morphodynamics to determine the potential for carbon storage within peat-filled valleys.Many studies have ascribed the presence of laterally continuous valley peat to the presence of dispersed wetland systems, i.e. systems without concentrated discharge in an established channel. However, our detailed investigations of the sedimentary records for peat-filled valleys show that channels were present even for systems characterized by low stream power. Here we show how these streams have formed highly sinuous planforms during the Holocene due to oblique aggradation, while stream power is too low for lateral migration (i.e. meandering). We also show that peat streams with a slightly higher degree of clastic sediment input show a different planform development than when clastic sediment input is limited, depending on the cohesivity of the sediments. We generalize our concepts for systems found around the world, such as in Canada, USA, Poland and Siberia. Finally, we will elaborate upon the upstream and downstream control of clastic sediments and hydrology on stream morphodynamics and peat growth in stream valleys.
| Period | 14 Dec 2023 |
|---|---|
| Event title | American Geophysical Union Fall Meeting 2023 (AGU, AGU23) |
| Event type | Conference/symposium |
| Location | San Francisco, United StatesShow on map |
| Degree of Recognition | International |