1. Tree-Ring Laboratory, Lamont-Doherty Geological Observatory, Palisades, NY 10964
2. Tasmanian Trades and Labour Council, Forestry Unit, New Town, Tasmania 7008, Australia
3. Tasmania Forestry Commission, Hobart, Tasmania 7001, Australia
4. Barbetti, N. W. G. Macintosh Centre, University of Sydney, New South Wales 2006, Australia
5. Commonwealth Scientific and Industrial Research Organization (CSIRO), Division of Atmospheric Research, Mordialloc, Victoria 3195, Australia
6. Climate Monitoring and Diagnostics Laboratory, National Oceanic and Atmospheric Administration, Boulder, Colorado 80309