1. CAS Key Laboratory of Forest Ecology and Management; Inst. of Applied Ecology, Chinese Academy of Sciences; Shenyang PR China
2. Swiss Federal Inst. for Forest; Snow and Landscape Research WSL; Zuercherstrasse 111 CH-8903 Birmensdorf Switzerland
3. Dept of Biology; Univ. of Fribourg; Fribourg Switzerland
4. Dept of Biology; Ghent Univ.; Ghent Belgium