ENAC Seminar Series by Dr M. Aeppli
Event details
| Date | 13.11.2020 |
| Hour | 17:00 › 17:45 |
| Speaker | Dr Meret Aeppli |
| Location |
Zoom
Online
|
| Category | Conferences - Seminars |
17:00 – 17:45 – Dr Meret Aeppli
Postdoctoral fellow at Stanford University, US
Tracking Electrons in Soils: How Electro-Active Minerals Affect Soil Carbon Turnover
Soil is a key component of the global carbon cycle that can intensify or mitigate climate change. Soil organic carbon also plays a pivotal role in soil stability, fertility, water-holding capacity, and biodiversity. Microorganisms transform soil organic carbon to greenhouse gases by coupling the oxidation of organic carbon compounds to the reduction of electron acceptors in microbial respiration. Solid phases containing redox-active elements, such as iron minerals, are often used in microbial respiration under oxygen-limited conditions. However, our understanding of this process and hence our ability to predict carbon turnover is limited because the electron accepting properties of minerals are largely unknown.
Recent research introduced an electrochemical approach to quantify electron transfer to minerals. This approach allows tracking electron transfer to minerals in soils. It can also be used to characterize the reactivity of minerals toward reduction under controlled conditions, allowing to compare reactivity across minerals and environmental conditions. Ongoing work on floodplain soils in the Rocky Mountains (Colorado, United States) indicates that mineral reactivity affects carbon turnover in these soils. In anoxic soil incubations, carbon dioxide was produced only in the presence of reactive minerals that were being used in microbial respiration but not in the presence of non-reactive minerals.
Future work aims to determine processes of soil organic carbon stabilization in Swiss mountain ecosystems by identifying the factors controlling microbial respiration, including interactions between organic carbon and minerals. Through systematic assessments of organic carbon stabilization across soil types, soil development stages and environmental conditions, this work aims to provide generalizable concepts to assess future changes in soil organic carbon stocks. The findings of past, current and future research will better our understanding of soil processes in the global carbon cycle and can inform the development of Earth System Models to improve predictions of carbon cycling.
Short bio:
Meret Aeppli is a postdoctoral research fellow at Stanford University. Her research focuses on biogeochemical processes that control the cycling of elements in soil systems. Her current work, which is funded by the Swiss National Science Foundation, aims to elucidate how electro-active minerals affect the turnover of carbon in floodplain soils. In addition to this work, Meret is involved in interdisciplinary collaborations with researchers at Stanford University and SLAC National Accelerator Laboratory that focus on the coupling of hydrological and biogeochemical processes in soils and effects of these processes on groundwater quality. In collaboration with researchers at UC Davis, she investigates redox processes in lake sediments and their effects on lake water chemistry. Meret holds a Bachelor's and a Master's degree in Environmental Sciences with a Major in Biogeochemistry and Pollutant Dynamics from ETH Zurich. She obtained her PhD from ETH Zurich in 2018. She was honored with the ETH Medal for her dissertation work in which she developed novel approaches to quantify the redox properties and reactivities of iron minerals.
Postdoctoral fellow at Stanford University, US
Tracking Electrons in Soils: How Electro-Active Minerals Affect Soil Carbon Turnover
Soil is a key component of the global carbon cycle that can intensify or mitigate climate change. Soil organic carbon also plays a pivotal role in soil stability, fertility, water-holding capacity, and biodiversity. Microorganisms transform soil organic carbon to greenhouse gases by coupling the oxidation of organic carbon compounds to the reduction of electron acceptors in microbial respiration. Solid phases containing redox-active elements, such as iron minerals, are often used in microbial respiration under oxygen-limited conditions. However, our understanding of this process and hence our ability to predict carbon turnover is limited because the electron accepting properties of minerals are largely unknown.
Recent research introduced an electrochemical approach to quantify electron transfer to minerals. This approach allows tracking electron transfer to minerals in soils. It can also be used to characterize the reactivity of minerals toward reduction under controlled conditions, allowing to compare reactivity across minerals and environmental conditions. Ongoing work on floodplain soils in the Rocky Mountains (Colorado, United States) indicates that mineral reactivity affects carbon turnover in these soils. In anoxic soil incubations, carbon dioxide was produced only in the presence of reactive minerals that were being used in microbial respiration but not in the presence of non-reactive minerals.
Future work aims to determine processes of soil organic carbon stabilization in Swiss mountain ecosystems by identifying the factors controlling microbial respiration, including interactions between organic carbon and minerals. Through systematic assessments of organic carbon stabilization across soil types, soil development stages and environmental conditions, this work aims to provide generalizable concepts to assess future changes in soil organic carbon stocks. The findings of past, current and future research will better our understanding of soil processes in the global carbon cycle and can inform the development of Earth System Models to improve predictions of carbon cycling.
Short bio:
Meret Aeppli is a postdoctoral research fellow at Stanford University. Her research focuses on biogeochemical processes that control the cycling of elements in soil systems. Her current work, which is funded by the Swiss National Science Foundation, aims to elucidate how electro-active minerals affect the turnover of carbon in floodplain soils. In addition to this work, Meret is involved in interdisciplinary collaborations with researchers at Stanford University and SLAC National Accelerator Laboratory that focus on the coupling of hydrological and biogeochemical processes in soils and effects of these processes on groundwater quality. In collaboration with researchers at UC Davis, she investigates redox processes in lake sediments and their effects on lake water chemistry. Meret holds a Bachelor's and a Master's degree in Environmental Sciences with a Major in Biogeochemistry and Pollutant Dynamics from ETH Zurich. She obtained her PhD from ETH Zurich in 2018. She was honored with 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
- Invitation required
- This event is internal
Organizer
- ENAC
Contact
- Cristina Perez