Technical Note—Dichotomous Keys for Scaling and Grading Merchantable Quality Sawlogs
This study documented and field-tested a simplified version of the Westside Grading Guidelines as published in the Official Rules Handbook by the Northwest Log Rules Advisory Group. A four-step dichotomous key was documented and field-tested to determine merchantable vs. nonmerchantable logs. The study also documented and field-tested an individual seven-step dichotomous log grading key for evaluating second-growth Douglas-fir (Pseudotsuga menziesii), Sitka spruce (Picea sitchensis), western hemlock (Tsuga heterophylla), and grand fir (Abies grandis) as derived from the Rules For Grading Logs section of the Official Rules Handbook. Results were compared with certified scalers employed by Yamhill Log Scaling & Grading Bureau and Columbia River Log Scaling & Grading Bureau. Eighty-four individuals measured the length, scaling diameter, determined merchantability versus nonmerchantability and assigned log grade for 440 logs. Results showed participants in the study correctly measuring log length 99% of time, scaling diameters were recorded correctly at an 89% rate, and merchantability and log grade at 98 and 97%, respectively. West. J. Appl. For. 18(4):250–258.
Keywords: Doughlas-fir; Merchantability; environmental management; forest; forest management; forest resources; forestry; forestry research; forestry science; grand fir; natural resource management; natural resources; sitka spruce; western hemlock
Document Type: Miscellaneous
Publication date: 01 October 2003