Christopher Deaderick Dr. Daniel Tinker Department of Botany

1. Growth release of subcanopy trees following Mountain Pine Beetle induced overstory mortality in Rocky Mountain National Park Christopher Deaderick Dr. Daniel Tinker Department of Botany PROPOSED RESEARCH PROJECT Introduction Importance of Study For the past decade, mountain pine beetles (MPB) have invaded millions of hectares of forest in Colorado and Wyoming, causing extensive conifer mortality. While it is commonly believed that growth rates of subcanopy trees increase following removal of overstory trees, limited empirical data exist to confirm this. Tree ring data can provide insights into such growth releases, as well as chronological occurrence of past climate and disturbance events and the severity and frequency of these events. By elucidating the growth response of subcanopy trees, this study will enhance understanding of important alterations in stand structure and composition following severe MPB forest mortality. The Mummy Range from Moraine Park, Rocky Mountain National Park Methods Purpose Statement The study area is located in Rocky Mountain National Park (RMNP) west of the Continental Divide in Lodgepole pine dominated forest severely impacted by MPB. In 2008 the MPB epidemic appeared to be subsiding during field surveys. Thirty-eight sites will be resampled, each containing two 20 m x 20 m square plots randomly positioned 90 m apart, for a total of 76 plots. In each plot tree core samples and tree diameter (DBH) will be collected for 5 trees of each canopy cohort and species type. Collecting densiometer measurements will estimate tree canopy cover. Tree core preparation and analysis will follow standard dendrochronological methods (Stokes and Smiley 1996). Tree ring crossdating matches the growth patterns of narrow and wide rings across the sampled trees to show past regional environmental factors that produce common year-to-year radial growth variations. This study will identify the timing and magnitude of growth release events detected from tree ring widths. This study will examine the magnitude of growth release of subcanopy trees following MPB-induced overstory mortality, and will estimate the differences in growth release among cohorts (vertical canopy layers) and among tree species. Hypothesis I hypothesize that there will be an increase in subcanopy growth as a result of decreased overstory cover and reduced competition for water, light and nutrients as a result of extensive mortality among mature trees. Relationship between wildfire synchrony, precipitation anomaly, and seedling establishment in the Black Hills, South Dakota (Brown 2006). Range of the mountain pine beetle in North America Acknowledgements Dr. Daniel Tinker Gregory Pappas McNair Scholars Program