1. Forestry and Natural Resource Extension, Department of Forest Engineering and Resources Management, Oregon State University , 631 Alder St., Myrtle Point, OR 97458 , USA
2. University of Florida, School of Forest, Fisheries, and Geomatics Sciences , 208 Newins-Zeigler Hall, PO Box 110410, Gainesville, FL 32611-0410 , USA
3. Forestry and Natural Resource Extension, Department of Forest Engineering and Resources Management, Oregon State University , 996 Jefferson St., Eugene, OR 97402 , USA