Common garden experiments to characterize cold acclimation responses in plants from different climatic regions

Cold acclimation is a crucial factor to consider in the context of ongoing climate change. Maladaptation with regard to frost damage and use of the growing season may occur depending on cold acclimation cues. Importance of photoperiod and preceding temperatures as cues needs therefore to be evaluated within (ecotypes) and among species. Common garden designs, in particular the (1) establishment of multiple common gardens along latitudinal/altitudinal gradients, (2) with in situ additional climate manipulations and (3) with manipulations in climate chambers are proposed as tools for the detection of local adaptations and relative importance of temperature and photoperiod as cues for cold adaptation. Here, we discuss issues in species and ecotype selection, establishment of common gardens including manipulations of temperature and photoperiod, and quantification of cold adaptation.