Special Seminar: Using observations to improve vegetation responses to climate in ESMs

Earth System Models (ESMs) are fundamental tools in climate prediction, and have demonstrated the large potential of land ecosystems to modulate climate change, through strong climate-land carbon cycle feedbacks. However, large uncertainties remain in how key eco-physiological and soil processes are represented in these models. There is now a wealth of observational data to help inform model development. I will give an overview of my research targeting several key uncertainties and how observational datasets can improve ESMs.
I will present work on the impacts of diffuse light effects on biogeochemistry, and how on cloudy days or under aerosol laden skies, plants enhance their carbon uptake. Under these conditions, although less total light reaches the plants, light is more evenly distributed through the canopy, with less shade and therefore a more illuminated lower canopy. The net result is an increase in plant photosynthesis, and I will show how accounting for this effect reduces uncertainty in global carbon budget assessments. I also show how plants can enhance their own photosynthesis by modulating their light environment. For example, the release of large quantities of plant volatiles into the atmosphere, which oxidize to form secondary organic aerosol, enhance diffuse light conditions and plant photosynthesis.
I will review work on thermal acclimation of photosynthesis and plant respiration, i.e. how plants adjust their physiology to warming. I will show the impact of incorporating this process into the UK ESM. I will also show results from my field experiment in the Colombian Andes on thermal acclimation of tropical montane and lowland species.
I will also cover work on plant respiration demonstrating that plant respiration decreases independent of temperature as the night progresses. Incorporation of this temperature independent respiration process into JULES, the land surface model of the UK ESM, leads to increase plant productivity up to 10% globally.
Finally, I will present ongoing work incorporating P cycling into JULES with an application for the Amazon forest.




13:30–14:45 Uhr


Bundesstr. 53, room 022/023
Seminar Room 022/023, Ground Floor, Bundesstrasse 53, 20146 Hamburg, Hamburg


Victor Brovkin

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