1. Department of Agronomy, Purdue University, Lilly Hall of Life Sciences, 915 West State Street, West Lafayette, IN 47907‐2054, USA;
2. Present address: Institute of Terrestrial Ecology, Swiss Federal Institute of Technology (ETH Zurich), Grabenstrasse 3, CH 8952, Schlieren, Switzerland
3. Department of Forestry & Natural Resources, Forestry Building, 195 Marsteller Street, West Lafayette, IN 47907‐2033, USA;
4. USDA Forest Service Southern Research Station, Forestry Sciences Laboratory, PO Box 12254, 3041 East Cornwallis Road, Research Triangle Park, NC 27709, USA;
5. Staatliches Museum für Naturkunde, Erbprinzenstrasse 13, D‐ 76133, Karlsruhe, Germany;