EESS talk on "Follow the electrons: insights into soil carbon cycling"

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Event details

Date 18.10.2022 12:1513:15  
Speaker Dr Meret Aeppli, Tenure Track Assistant professor, Soil Biogeochemistry Laboratory (SOIL), ALPOLE-Sion
Location Online
Category Conferences - Seminars
Event Language English
Abstract:
Electron transfer reactions are central to the transformation of energy in the environment and underpin most biogeochemical cycles on Earth. In soil, one of the main drivers of carbon cycling is the activity of heterotrophic organisms that utilize the energy stored in soil organic matter by coupling the oxidation of organic carbon to the reduction of electron acceptors. Yet, our understanding of this process is incomplete and the response of the soil carbon pool to climate change remains one of the primary sources of uncertainty in projections of atmospheric carbon dioxide concentrations.
Here, I discuss how we can track electron transfer reactions and relate them to bioenergetic descriptors to elucidate the processes and mechanisms that control soil heterotrophic respiration. First, I present an approach to characterize the redox properties of iron minerals, which are abundant electron acceptors in many soils. Second, I show how the kinetics of electron transfer and carbon dioxide production in soil incubations are related to the redox properties of electron acceptors. Third, I demonstrate how we can quantify electron transfer to iron in a simulated soil system with groundwater flow that includes transport of microorganisms and organic carbon substrates. Future work aims to to expand on the presented concepts by integrating electron transfer properties of soil organic matter into bioenergetic frameworks.

Short biography:
Meret Aeppli joined EPFL as a tenure track assistant professor and head of the soil biogeochemistry laboratory (SOIL) in September 2022. Her group aims to understand the fundamental principles and processes that govern the biogeochemical cycling of key elements in soil. Meret was a postdoctoral fellow at Stanford University in the department of Earth System Science from 2019 to 2022 where she studied biogeochemical controls on carbon turnover in soils and sediments. She holds a Bachelor's and a Master's degree in Environmental Sciences from ETH Zurich and obtained her PhD from ETH Zurich in 2018. She was awarded the ETH Medal for her dissertation work in which she developed novel approaches to quantify the redox properties and reactivities of iron minerals

Practical information

  • General public
  • Free
  • This event is internal

Organizer

  • EESS - IIE

Contact

  • Prof. D. Andrew Barry, IIE Director

Tags

Soil biogeochemistry redox thermodynamics iron carbon

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