1. Department of Forest Mycology and Pathology, Uppsala BioCentre, SLU, Box 7026, 750 07 Uppsala, Sweden.
2. Department of Biology, Indiana University, Bloomington, IN 47405, USA.
3. Imperial College London and Royal Botanic Gardens, Kew, London TW9 3DS, UK.
4. The University of Aberdeen and James Hutton Institute, Aberdeen AB24 3UU, UK.
5. Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48109, USA.