John A. Kershaw, Jr. is Professor of Forest Mensuration and Biometrics at the University of New Brunswick, Canada. Mark J. Ducey is Professor of Natural Resources and the Environment at the University of New Hampshire, USA. Tzeng Yih Lam is Assistant Professor of Forest Measurements at the University of British Columbia, Canada. Thomas W. Beers is Professor Emeritus of Forestry Measurement and Biometry at Purdue University, USA.