Persistence of Pinyon Pine Snags and Logs in Southwestern Colorado

Abstract

Abstract We examined the persistence of pinyon pine (Pinus edulis Engelm.) standing snags and downed logs in southwestern Colorado pinyon-juniper woodlands. The time since death of pinyon pines killed by bark beetles, black stain root disease, or unknown causes in three study areas in southwestern Colorado was determined through monitoring of permanent plots and dendrochronological crossdating methods. The structural condition and form of the trees was recorded and related to the time since death. Pinyon snags may persist for up to 25 years, with persistence of intact snags averaging 8.4 years and broken snags averaging 13.2 years. Sound logs had been dead for a mean of 9.8 years, whereas more fragmented logs had been dead for a mean of 14.4 years. Extremely fragmented trees had been dead for 16.2 years. There was no statistically significant difference in the time since death for snags versus logs in similar condition classes. A simplified rating system to determine the number of years dead for pinyon pine based on form and condition is provided. West. J. Appl. For. 20(4):247–252.