The PhD defence and trial lecture will be held in Auditorium 1 in The Geology Building. In some cases, it will be possible to attend the trial lecture and dissertation digitally, in that case a link to Zoom will be posted.
Trial lecture
Tuesday 18 June, 10:15-11:00, Aud 1, The Geology Building:
Ecosystem services of high-latitude soils in a changing climate
Conferral summary (in Norwegian)
Mikrobielle prosesser kan stimulere og svekke karbonbinding i jordsmonnet, og kan påvirkes av klimaendringer. Tradisjonelle modeller for klimaprojeksjoner mangler en god komponent for jordkarbon. I avhandlingen er det utviklet og presenteres en jordkarbonmodell som eksplisitt representerer mikrober som bakterier og sopp. Vi viser at modellen representerer jordkarbon godt i kalde områder, og fanger opp viktige interaksjoner mellom ulike jordmikrober.
Main research findings
Popular scientific article about Aas’s dissertation:
To mimic microbes with models: Development and application of the microbially explicit soil model MIMICS+ in cold climates
A major uncertainty in current climate projections is whether soils will act as a net sink or source of atmospheric carbon. Through decomposition and respiration, soil microbes like bacteria and fungi largely control the carbon exchange between soils and the atmosphere. These exchanges are dependent on factors like temperature, moisture, and nutrient availability. Yet, the traditional soil sub-models used in Earth System Models lack a proper representation of these processes.
This work presents and applies a new soil model, MIMICS+. It builds on an existing model (MIMICS) which represents the decomposition of dead plant material and soil organic matter by two microbial groups. With MIMICS+, we extend this framework by introducing symbiotic fungi (mycorrhiza), a nitrogen cycle, and vertical layers. The model performs better or on par with a traditional model when compared to forested Norwegian sites, and broadly captures climatic and litter quality controls on decomposition rates. We also show that the presence of mycorrhizal fungi can affect carbon storage and respiration through nutrient competition with microbial decomposers. In the future MIMICS+ will represent an improved soil sub-model in the Norwegian Earth System Model, thus contributing to a deeper understanding of how soil and microorganisms respond to climate change.
Photo and other information:
Press photo: Elin Cecilie Ristorp Aas, portrait; 1000px. Photo: Private
Other photo material: Figure with description and credit as specified in the article above, size 1200px.
