CLIMATE SENSITIVITY AND GROWTH RESPONSE OF TWO CONIFERS ON HIGH ELEVATION RIDGE AT WOLF KNOB, SHOSHONE FOREST, WY

The North American Dendroecological Field Week (NADEF) is an intensive dendrochronology-based research workshop, funded by the National Science Foundation. The 2019 Introductory Group at NADEF focused on learning the fundamental skills of dendrochronology, including: proper field sampling techniques, sample preparation (mounting/sanding), dotting/dating, measuring, cross dating, and preliminary analysis. Precisely-dated total ring width chronologies were developed for Pinus contorta (Lodgepole Pine) and Pinus flexilis (Limber Pine) at the Wolf Knob field site, located in the Greater Yellowstone Area. This is a moisture-limited environment, which reduces stem density and competition, thus making this an ideal site to investigate climate. Here, we show that these two species exhibit differing associations with climate variability and ecological changes. Both species show a positive correlation with monthly precipitation and a negative correlation with mean monthly temperature. When compared with the Palmer Drought Severity Index (PDSI), radial growth increments of lodgepole pine are correlated with the more large-scale Western U.S. drought pattern, while those of limber pine respond to more localized, small-scale drought events. After examining the age distribution for both species, the lodgepole pine demonstrate episodic regeneration; two distinct cohorts established 100 years ago (c. 1900) and 300 years ago (c. 1700), while the limber pine show continuous regeneration.