Updated Chittenden Bridge Chronology of Lodgepole Pine (Pinus contorta) in the Greater Yellowstone Ecosystem

Keywords: Dendrochronology, Greater Yellowstone Ecosystem, Detrending, Lodgepole Pine
Session Type: Virtual Guided Poster Abstract
Day: Monday
Session Start / End Time: 2/28/2022 05:20 PM (Eastern Time (US & Canada)) - 2/28/2022 06:40 PM (Eastern Time (US & Canada))
Room: Virtual 40

Abstract

In 2011, researchers created a chronology spanning from 1680 to 2010 in the Greater Yellowstone Ecosystem at the Chittenden Bridge site located in northwestern Wyoming, near the Upper Yellowstone Falls Chittenden Bridge (44.7117, -110.5002). During the summer of 2020 during the North American Dendroecological Fieldweek, we collected tree cores from Lodgepole Pine (Pinus contorta) to update the chronology from 2010. During the 2020 collection season, sampling efforts were focused on older trees growing in extremely rocky microsites, whose restricted rooting zones would make them more sensitive to variations in climate. Twelve trees were selected for sampling at the site and two samples were from each tree. We conducted analyses between the previous and updated chronologies for the Chittenden Bridge site and we detected weak support for any repeat sampling of individual trees. Using a two-thirds smoothing spline, we detrended the combined chronologies for further growth-climate analysis. We then used the PRISM dataset to correlate monthly precipitation, minimum temperature, maximum temperature with the combined chronology. Using the KNMI Climate Explorer tool, we graphically represented spatial correlations between growth and climate for the Greater Yellowstone Ecosystem and surrounding region. Overall, we found the trees in the region are becoming more sensitive to minimum temperature over time, winter maximum temperature is positively correlated with tree ring growth, previous maximum temperature during the summer months are negatively correlated with tree ring growth, and June precipitation is strongly positively correlated with tree growth.