1. Bordeaux Sciences Agro INRA UMR 1391 ISPA Gradignan F‐33170 France
2. Nicholas School of the Environment Duke University Durham North Carolina 27708
3. Department of Biology Western University London Ontario Canada
4. The R.H. Smith Institute of Plant Sciences and Genetics in Agriculture, The R.H. Smith Faculty of Agriculture, Food and Environment The Hebrew University of Jerusalem Rehovot 76100 Israel
5. Institute of Botany and Ecology University of Tartu 51005 Tartu Estonia
6. Department of Biology University of New Mexico Albuquerque New Mexico 87131
7. Department of Forest Sciences University of Helsinki Helsinki FI‐00014 Finland