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Humboldt-Universität zu Berlin - IRI THESys

Impacts of climate variability and extremes on agricultural productivity: Improved crop modelling as a precondition for food security assessments

Bernhard Schauberger is a PhD candidate at PIK Potsdam and HU. His research interests include variability of crop yields and the associated drivers, the influence of climate change on food security and the global modelling of these relationships.


The world population is growing, and with it the challenge of food security. The trend for future crop yields is uncertain in the face of limited soil resources and, in particular, a changing climate. Variability in climate is known to cause variability in crop yields. Thus, with the prospect of a warmer and more fluctuating climate, also yields are expected to become more variable. Especially so-called extreme events like prolonged drought, unusually high temperatures or torrential floods can do great harm to agricultural production. While yield losses which are temporally or spatially rare may be buffered, a series of heavy harvest losses can lead to catastrophic cascade effects, as observed recently with food export bans and ensuing price spikes in 2008 or 2010. Thus, it is vital to understand the influence of climate on yields via different physiological plant processes. These effects can be investigated with computational crop models depicting essential plant processes. One type, so-called Global Gridded Crop Models can project future yields under different climate scenarios for the whole globe, a necessity to understand the risks of climate effects simultaneously affecting large parts of the world. In my thesis, I will first summarize the current state of knowledge on plant processes creating yield variability for the four main global food crops (maize, rice, soy, wheat) and also review the influence of climate on them, with a particular focus on extreme events. In a second step, the processes will be sorted by importance as defined by their possible impacts on yields and their probability of changing in future climates. In addition, their current implementation in one state-of-the-art crop model (LPJmL) will be evaluated. The third and main part of my thesis consists in the implementation of one selected process in LPJmL. This process will be chosen according to its importance, and its necessary parameters will be calibrated with a Bayesian approach to best match real-world data from field studies. This research is envisaged to contribute significantly to understanding the impacts of climate change on crop yields, and which plant processes form this response. Finally it can provide input to economic models that further quantify the resulting risks to future food security.

Bernhard Schauberger is a doctorate student at PIK Potsdam since May 2014 and a research assistant since Oct. 2013. From June 2011 till Sept. 2013 he worked as a renewable energy consultant in Grassau (near lake Chiemsee in Bavaria). Before, he studied bioinformatics at TUM & LMU Munich from 2005 till 2011 and graduated with distinction. An 8-month stay in Arequipa (Peru) as an English teacher has raised his interest for environmental issues.




Bernhard Schauberger, Doctoral Researcher
THESys Graduate Program
Phone: +49 (0)331 331 288 2436
E-mail: schauber@pik-potsdam.de