Post-fire soil carbon dynamics: implications on movement of particulate and dissolved pyrogenic carbon.
Fire, erosion, and soil carbon (C) dynamics overlap in space and time. Increased rates of erosion typically follow wildfires, and fire-altered or pyrogenic C (PyC, also referred to as black carbon) is redistributed vertically within soil profiles and laterally to lower landform positions along hillslopes, changing soil’s C sequestration trajectory. Using case studies from wildfires that occurred in the Sierra Nevada Mountains (USA) I will discuss how the composition and magnitude of PyC redistributed by erosion varies considerably depending on fire severity and geomorphology of the landscape. Furthermore, our work demonstrates how PyC’s hydrologic interactions determine: the amount that will enter the soil profile and experience microbial and geochemical alterations, whether it will be buried in depositional environments and stored on the landscape, or if it will be transported to streams and eventually to the ocean. This crucial first interaction with the hydrologic cycle occurs on the timescale of days to weeks, and therefore supersedes microbial decomposition as the primary control on charcoal’s environmental persistence.
Professor of Soil Biogeochemistry and Falasco Chair in Earth Sciences at the Department of Life and Environmental Sciences
University of California, Merced.
Other appointments: Interim Associate Dean of Graduate Education at UC Merced; Past Chair of the US National Committee on Soil Science at the National Academies of Science, Engineering, and Medicine; Associate Editor of AGU’s Journal of Geophysical Research – Biogeosciences and Elementa.
Education: Ph.D. in Biogeochemistry from the University of California (UC), Berkeley; M. Sc. in Resource Development (Political Ecology) from Michigan State University, and B. Sc. in Soil and Water Conservation from University of Asmara, Eritrea. Postdoc: University of California President’s Postdoctoral Fellow at UC Berkeley and UC Davis.
Research focus: biogeochemical cycling of essential elements in the soil system, global change science, nano-geochemistry, political ecology of land degradation and ownership.
Recognitions: recipient of several awards and honors, including the National Science Foundation’s CAREER award, Fellow and Bromery Award from Geological Society of America, and is a member of the inaugural class of the US National Academies of Science, Engineering and Medicine’s New Voices in Science, Engineering, and Medicine.