Temperature measurements were made to better understand the role of microclimate on mountain pine beetle, Dendroctonus ponderosae Hopkins (Coleoptera: Scolytidae), activity as a result of thinning lodgepole pine stands. Sampling was done over 61 days on the north slope of the Unita Mountain Range in northeastern Utah. Principal components analysis was applied to all temperature variables. Most of the variation was attributed to two variables, coolest part of the night and hottest part of the day. The thinned stand was approximately 1 °C warmer than the unthinned stand. Day temperature was 10 to 11 °C higher than the corresponding night temperature. Models were developed to predict phloem temperature from bark surface temperature. The resultant equations had r2 values of 0.98 or greater.
Bartos, Dale L.; Booth, Gordon D. 1994. Effects of thinning on temperature dynamics and mountain pine beetle activity in a lodgepole pine stand. Res. Pap. INT-RP-479. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Research Station. 9 p.