1. Research Branch; Agriculture and Agri-Food Canada; Ottawa, Ontario; Canada
2. Global Carbon Project; Marine and Atmospheric Research, CSIRO; Canberra, ACT; Australia
3. Department of Botany; University of Florida; Gainesville; Florida; USA
4. Department of Physical Geography and Quaternary Geology; Stockholm University; Stockholm; Sweden
5. Komi Science Center; Russian Academy of Sciences; Syktyvkar; Russia
6. Northeast Science Station; Russian Academy of Sciences; Cherskii; Russia