Ken Lertzman, Simon Fraser University Daniel Gavin, Department of Plant Biology, University of Illinois, Urbana, IL 61801, USA Douglas Hallett, Center for Environmental Sciences & Quaternary Sciences Program, Northern Arizon Linda Brubaker, College of Forest Resources, University of Washington, Seattle, WA 98195, USA Dana Lepofsky, Simon Fraser University Rolf Mathewes, Department of Biological Sciences, Simon Fraser University |