1. Department of Earth and Environmental Sciences, Lamont‐Doherty Earth Observatory, Columbia University, Palisades, NY 10964‐8000,
2. Department of Biology, Texas Technical University, Lubbock, TX 79409‐3131, USA,
3. Department of Plant and Microbial Sciences, University of Canterbury, Private Bag 4800, Christchurch,
4. Landcare Research, PO Box 69, Lincoln 8152, and
5. New Zealand Forest Research Institute, PO Box 29237, Christchurch, New Zealand