ERC Consolidator Grant · 2026–2031
Every spring, trees across the temperate and boreal world burst into leaf — a moment that sets the rhythm for the entire growing season. The timing of this event determines how forests grow, how early food webs spring to life, and how resilient ecosystems remain in a warming world. Yet one of the most fundamental controls on spring leaf-out remains poorly understood: winter cold.
Before trees can respond to the warmth of spring, they must first experience sufficient cold during winter — a process known as chilling. Without it, buds cannot break, and in extreme cases, leaf-out may fail entirely. As winters warm, this chilling requirement is increasingly at risk of going unmet across large parts of the temperate zone, with potentially far-reaching consequences for forest productivity, carbon cycles, and biodiversity.
CHILL-TIME addresses this gap directly. Through large-scale experiments, long-term common garden observations spanning more than two decades, and integration with satellite data and global vegetation models, the project will quantify the chilling thresholds of temperate and boreal trees for the first time at this scale. A central question is how these requirements vary across species, biogeographic regions, and climate zones — and what this means for predicting the future of forests under continued warming.
The project is organized around four interconnected work packages: experimental quantification of chilling temperature bounds, analysis of long-term phenological shifts across more than 1,000 species, spatial mapping of phenological traits across the Northern Hemisphere, and integration of findings into a dynamic global vegetation model to project growing season changes through 2100.
CHILL-TIME is funded by the European Research Council (ERC Consolidator Grant) and hosted at BRANCH Institute.