1. School of Botany and Zoology, The Australian National University, Canberra, ACT 0200, Australia.
2. School of Resources, Environment and Society, The Australian National University, Canberra, ACT 0200, Australia.
3. Forests NSW, P.O. Box J19, Coffs Harbour NSW 2450, Australia.
4. Institute of Silviculture, Freiburg University, D-79085 Freiburg, Germany.