Consequences of extreme drought events for soil functioning

Ecosystems are increasingly exposed to climate warming-induced changes in precipitation patterns, leading to more frequent and extreme drought and rainfall events. Soil moisture, which is dependent on rainfall supply, is one of the primary regulators of soil microbial activity and soil functioning. Hence, drought-induced changes in microbial community composition and activity may have major impacts on crucial ecosystem functions such as carbon cycling. However, the long-term consequences of altered precipitation patterns for microbial processes in soil remain largely unexplored. This severely hampers our ability to predict how the intensity and frequency of drought and rainfall events affect the microbial regulation of the carbon cycle. In this project I aim to examine how the long-term consequences of altered precipitation patterns influence soil microbial activity and associated functions involved in carbon cycling. I will study this in soils from a unique network of existing long-term (8-15 years) field experiments mimicking summer drought scenarios. In addition, I will perform laboratory experiments to elucidate the main drivers of microbial functioning (growth and activity) under drought and rainfall events. Together, these experiments will advance our understanding of the impacts of altered precipitation patterns on terrestrial ecosystem functioning and associated ecosystem services to humans.