1. CEFE, Univ Montpellier, CNRS, EPHE, IRD , 1919 route de Mende, 34090 Montpellier , France
2. Department of Plant Biology and Ecology, University of the Basque Country (UPV/EHU) , Barrio Sarriena s/n, 48940 Leioa , Spain
3. Forest Research Center, INIA, CSIC , Ctra A Coruña km 7.5, 28040, Madrid , Spain
4. Département des Sciences Biologiques, Université du Québec A Montréal , CP 8888 Succursale Centre-ville, Montréal, Québec H3C 3P8 , Canada