News & Events

INSTAAR Seminar: Post-fire transport and persistence of pyrogenic carbon in soil

Thursday, October 11, 2018, 3:30PM - 4:30PM

Speaker

Asmeret Berhe

Location:

Sievers room, SEEC S228

Fire and erosion are important controllers of biogeochemical cycling of essential elements. Pyrogenic carbon (PyC, fire-altered C) constitutes an important pool of soil organic matter (SOM), particularly for its reactivity and because of its assumed long residence times in soil. Past work on PyC dynamics in soil had focused on decomposition as the most important loss pathway for PyC from soil. However, the low density of PyC and its high concentration on the soil surface after fire indicates that a significant proportion of PyC formed or deposited on the soil surface is likely laterally transported away from the site of production by wind and water erosion. Current reports of PyC MRT range from 250 to 660 years. Using a specific example-based model system, we find that ignoring the role of erosion may lead to the under- or over-estimation of PyC mean residence time on the centennial time scale. In this talk, I will demonstrate how erosion constitutes an important PyC flux that can act as a significant control on the stock and residence time of PyC in the soil system.