ENAC Seminar Series by Dr A. Ebrahimi
Event details
| Date | 03.11.2020 |
| Hour | 15:00 › 15:45 |
| Speaker | Dr Ali Ebrahimi |
| Location |
Zoom
Online
|
| Category | Conferences - Seminars |
15:00 – 15:45 – Dr Ali Ebrahimi
Postdoc at Massachusetts Institute of Technology (MIT), Cambridge, USA
Microbial community dynamics in soil aggregates shape carbon and nitrogen cycles at the ecosystem level
Soil microbial community dynamics and function play a key role in shaping the global biogeochemical cycles with a significant impact on soil health and productivity. The complex ecological functioning of microbial communities is often promoted by multispecies interactions in soil biological hotspots such as soil aggregates. Microbial communities inhabiting soil aggregates dynamically adjust their activity and composition in response to variations in water content and availability of carbon and nitrogen. These dynamics shape signatures of biogeochemical activity and gas fluxes from soil profiles. In this talk, I will represent a novel mechanistic model to bridge the various scales of relevance to soil microbial processes ranging from pores to aggregates and soil profiles. The model reveals a dynamic interplay between oxic and anoxic microsites that are jointly shaped by water dynamics and the self-organization of aerobic and anaerobic microbial communities. The spatial extent of anoxic niches (hotspots) flicker in time (hot moments) and support significant anaerobic microbial activity even in aerated soil profiles. The results quantify impacts of aggregate size distribution and dynamic shifts in water content on CO2 and N2O production rates in soil profiles in good agreement with our “soil column” experimental data.
I will then present how socio-ecological interactions among microbes contribute to decompose complex particulate organic matter as the key step in the global carbon cycle. Using a combination of computational models and experiments, I will show that microbial populations “team-up” by forming multicellular units to degrade recalcitrant particulate organic matter where individual cells facilitate each other’s activity. I will end by discussing how these results could help to predict the carbon use efficiency at the ecosystem level and how to engineer scenarios to facilitate the degradation of recalcitrant plastics in nature.
Short bio:
Ali Ebrahimi is an SNSF (Swiss National Science Foundation) postdoctoral fellow in Parsons lab at Massachusetts Institute of Technology, specializing in microbial ecology and soil physics. He is interested in understanding the mechanisms that control microbial processes at the micrometer scale and their impact on the ecosystem functions such as the carbon cycle. Ali received his MSc in Chemical Engineering from Sharif University of Technology (Tehran, Iran). He completed his Ph.D. at ETH Zurich, focusing on developing mechanistic models for microbial processes in soil aggregates where he received ETH medal for his outstanding dissertation. Ali is also the recipient of two PostDoc Mobility Fellowships from the Swiss National Science Foundation. Ali is a scientific collaborator and consultant in multiple environmental restoration and protection projects around the globe including sustainable land management in the black soil region of northeast china and water resources restoration in Iran under drought stress.
Postdoc at Massachusetts Institute of Technology (MIT), Cambridge, USA
Microbial community dynamics in soil aggregates shape carbon and nitrogen cycles at the ecosystem level
Soil microbial community dynamics and function play a key role in shaping the global biogeochemical cycles with a significant impact on soil health and productivity. The complex ecological functioning of microbial communities is often promoted by multispecies interactions in soil biological hotspots such as soil aggregates. Microbial communities inhabiting soil aggregates dynamically adjust their activity and composition in response to variations in water content and availability of carbon and nitrogen. These dynamics shape signatures of biogeochemical activity and gas fluxes from soil profiles. In this talk, I will represent a novel mechanistic model to bridge the various scales of relevance to soil microbial processes ranging from pores to aggregates and soil profiles. The model reveals a dynamic interplay between oxic and anoxic microsites that are jointly shaped by water dynamics and the self-organization of aerobic and anaerobic microbial communities. The spatial extent of anoxic niches (hotspots) flicker in time (hot moments) and support significant anaerobic microbial activity even in aerated soil profiles. The results quantify impacts of aggregate size distribution and dynamic shifts in water content on CO2 and N2O production rates in soil profiles in good agreement with our “soil column” experimental data.
I will then present how socio-ecological interactions among microbes contribute to decompose complex particulate organic matter as the key step in the global carbon cycle. Using a combination of computational models and experiments, I will show that microbial populations “team-up” by forming multicellular units to degrade recalcitrant particulate organic matter where individual cells facilitate each other’s activity. I will end by discussing how these results could help to predict the carbon use efficiency at the ecosystem level and how to engineer scenarios to facilitate the degradation of recalcitrant plastics in nature.
Short bio:
Ali Ebrahimi is an SNSF (Swiss National Science Foundation) postdoctoral fellow in Parsons lab at Massachusetts Institute of Technology, specializing in microbial ecology and soil physics. He is interested in understanding the mechanisms that control microbial processes at the micrometer scale and their impact on the ecosystem functions such as the carbon cycle. Ali received his MSc in Chemical Engineering from Sharif University of Technology (Tehran, Iran). He completed his Ph.D. at ETH Zurich, focusing on developing mechanistic models for microbial processes in soil aggregates where he received ETH medal for his outstanding dissertation. Ali is also the recipient of two PostDoc Mobility Fellowships from the Swiss National Science Foundation. Ali is a scientific collaborator and consultant in multiple environmental restoration and protection projects around the globe including sustainable land management in the black soil region of northeast china and water resources restoration in Iran under drought stress.
Practical information
- General public
- Invitation required
- This event is internal
Organizer
- ENAC
Contact
- Cristina Perez