Veneer recovery from beetle-killed spruce trees, Kenai Peninsula, Alaska

Abstract

A four-level, visual classification system based on tree condition was developed for beetle-killed spruce on the Kenai Peninsula, Alaska. The veneer recovery study estimated volume and value of veneer recovered from trees in all but the most deteriorated class (class 4). Trees were selected by dbh and deterioration class from plots spanning the peninsula. Results showed significantly lower recovery of both volume and value for logs from dead trees compared to logs from live trees. Volume and value recovery did not statistically differ between deterioration classes 2 and 3. There was about a 6% difference in cubic recovery between logs and veneer blocks from live (class 1) and dead (classes 2 and 3) trees. Defect present before beetle attack (existing defect) played a significant role in recovery results. Models were developed by deterioration classes incorporating losses from existing defect. Each 1% of existing defect translated to a decrease of 0.4% in cubic recovery and a loss of $1.96/CCF of gross woods-length log volume. The recommendation is to have two deterioration classes: one for live and infested trees and a second for dead trees. These two classes are sufficient for evaluating veneer recovery.