1. School of Arts, Science and Education, Medicine Hat College, 299 College Drive S.E., Medicine Hat, AB T1A 3Y6, Canada
2. Forest Science, Planning and Practices Branch, British Columbia Ministry of Forests, Victoria, B.C. V8V 1T7, Canada
3. Centre for Forest Biology, University of Victoria, Victoria, PO Box 3020 STN CSC, B.C. V8W 2Y2, Canada