1. Swiss Federal Institute for Forest, Snow and Landscape Research WSL Birmensdorf Switzerland
2. IGN, Direction Interrégionale Nord‐Est Champigneulles France
3. UMR LERFoB, AgroParisTech, INRA Nancy France
4. BotanikBasel University Basel Switzerland
5. Laboratory of Tree‐Ring ResearchUniversity of Arizona Tucson Arizona