1. Department of Environmental Science—Botany University of Basel Basel Switzerland
2. Research Unit of Forest Dynamics, Research Group of Ecosystem Ecology Stable Isotope Research Centre, Swiss Federal Institute for Forest, Snow and Landscape Research WSL Birmendsorf Switzerland
3. Research School of Biology, College of Science Australian National University Canberra Australian Capital Territory Australia
4. Institut de Recherche en Horticulture et Semences, Université d'Angers, INRAe Beaucouzé France