1. Department of Forest Resources and Environmental Conservation; Virginia Tech; 304 Cheatham Hall, Blacksburg VA 24061 USA
2. Department of Forest and Conservation Sciences; University of British Columbia; 3041-2424 Main Mall, Vancouver BC V6T1Z4 Canada
3. Department of Biological Sciences; University of Alberta, 5-108 Centennial Centre for Interdisciplinary Science; Edmonton AB T6G2E9 Canada
4. Mediterranean Forest Ecology (URFM); Institut National de la Recherche Agronomique (INRA); Domaine St Paul, Site Agroparc, 84914 Avignon France
5. BIOGECO; INRA, Universite de Bordeaux; 69 Route d'Arcachon, 33612 Cestas France
6. Institute of Ecology; Universidad Nacional Autonoma de Mexico (UNAM) Circuito Exterior s/n, Apartado Postal 70-275, 04510 Ciudad de México; Mexico City Mexico
7. Department of Botany and Biodiversity Research; University of Vienna Faculty of Life SciencesRennweg 14, Room 217, A-1030; Vienna Austria
8. Department of Entomology and Plant Pathology; University of Tennessee, 370 Plant Biotechnology Building, 2505 EJ Chapman Drive; Knoxville TN 37996 USA
9. Department of Forestry and Environmental Resources; North Carolina State University Jordan Hall Addition 5231; Raleigh NC 27695 USA