Professor Jeffrey A Nittrouer - Geomorphic Evolution of Peatland Streams: Uniquely Boring but Ecologically Critical Landscape Systems

IAS Residential Fellow Professor Jeffrey A. Nittrouer delivers a seminar on their research -  Peatland environments cover 3% of the planet’s land surface, yet possess 30% of its terrestrial organic carbon. The hydrology of peatlands is critical to establishing carbon-storage capabilities. The surface-water system consists of lakes and bogs connected by low-sloping streams that transport minimal amounts of inorganic sediment. Over time, peatland streams aggrade due to accumulation of organic matter, thereby filling their valleys. We use remote-sensing techniques and field observations to quantify rates of lateral mobility, and these data inform a numerical modeling framework that evaluates migration habit. A fundamental control on peat stream mobility is inorganic sediment content: Where unconsolidated material is added to the system the stream bed and floodplain aggrade rapidly, driving changes in channel morphology and increasing lateral migration rates. How such dynamics adjust to scenarios of altered hydrological regimes is discussed; in particular, how changing water and sediment runoff could liberate sequestered organic carbon, leading to respiration. For more information about the IAS, please visit - https://www.lboro.ac.uk/research/ias