Tolerance of stressful conditions and of environmental variability is a precondition for the long-term
persistence of populations and species, and all the more important in the light of ongoing global
climatic changes. One important way of how organisms can adjust to environmental variation is by
modifying gene expression. Using the example of the model lichen Lobaria pulmonaria (tree
lungwort), the planned research investigates how gene expression responses to environmental
variation can be partitioned into genetic, acclimatory, and biotic components. Growth is the best
proxy for fitness in lichens because it reflects the overall carbon balance of this mutualistic symbiotic
association. Growth responses will be measured and partitioned into genetic, acclimatory and biotic
effects. The planned project will substantially improve the understanding of how symbiotic
organisms respond to environmental variation.