1. Arnold Arboretum of Harvard University; 1300 Centre Street Boston MA 02131 USA
2. School of Science; University of Waikato; Hamilton 3240 New Zealand
3. Department of Environmental Conservation; University of Massachusetts; 160 Holdsworth Way Amherst MA 01003 USA
4. Institute of Botany; University of Basel; Schoenbeinstrasse 6 4056 Basel Switzerland
5. School of GeoSciences; University of Edinburgh; Crew Building, West Mains Road EH9 3JN Edinburgh UK
6. ICREA at CREAF; Campus de UAB; Cerdanyola del Valles Barcelona 08023 Spain
7. Earth and Environmental Sciences Division; Los Alamos National Laboratory; Los Alamos NM 87545 USA
8. Plant Biology Section, School of Integrative Plant Science; Cornell University; Ithaca NY 14853 USA
9. Department of Agronomy; Purdue University; West Lafayette IN 47907 USA