D3451: Saproxylic beetle community responses to varying levels of tree mortality following a significant western pine beetle, Dendroctonus brevicomis (Curculionidae: Curculionidae), driven mortality event in the central and southern Sierra Nevada

Panel traps baited with high-release ethanol were deployed to survey saproxylic beetle communities in the wake of a major drought and western pine beetle, Dendroctonus brevicomis LeCont, driven ponderosa pine mortality event in California (2012-2015). Traps were deployed over two field seasons in 2022 and 2023 primarily utilizing a network of plots established to monitor and quantify forest response to this significant mortality event. In year one, we selected plots with high mortality (at least 50% of trees on the plot) and either low (less than 50%) or high (at least 60%) snag-fall. We compared these sites to plots with lower mortality (less than 30%) as control sites. In year two, we placed control traps on newly created plots without any recent western pine beetle activity. Beetles were identified to families and diversity and richness were compared. Specimens from four families, Buprestidae, Cerambycidae, Curculionidae (scolytinae only), and Elateridae, were identified to genus for further analysis. Alpha, beta, and gamma diversity was calculated for each disturbance category for each year. Additional community comparisons were made utilizing Non-Metric Multidimensional Scaling techniques. Results and their implications are discussed.