Authors: Stockton Maxwell*, Radford University, Grant Harley, University of Idaho, Sanjay Bhandari, Indiana State University, Sunshine Brosi, Frostburg State University, Olivia Hinton, California State University - Fullerton, Christine Lucas, University of the Republic - Uruguay, Lara Van Akker, Canadian Forest Service
Topics: Paleoenvironmental Change, Biogeography, Physical Geography
Keywords: dendrochronology, paleoclimatology, tree ring, water resources, Yellowstone
Session Type: Poster
Start / End Time: 3:05 PM / 4:45 PM
Room: Lincoln 2, Marriott, Exhibition Level
Presentation File: No File Uploaded
The Greater Yellowstone Ecosystem (GYE) is the headwaters for seven major rivers in the western US with waters flowing to the Pacific Ocean, Gulf of California, and the Gulf of Mexico. These waters are key to ecosystem functioning, recreation, and human consumption. Here, we reconstruct the Yellowstone River, Bighorn River, and regional snowpack (Apr 1 snow water equivalent; SWE) to provide a multi-century context for contemporary changes in water resources. We employed a nested principal components regression model driven by chronologies from multiple species growing in the intermontane region. All reconstruction models explained greater than 60% of the instrumental variance and have strong verification statistics for the past millennium. Reconstructed streamflow for both rivers indicated that the observed record does not represent the full range of variability over the past ca. 1000 years, including anomalous pluvials in the 1600s CE and prolonged drought in the 900s CE. Reconstructed SWE showed that the trend in recent decades was not represented in the past several centuries either. Further analysis of reconstructed snowpack indicated that 20th and 21st century warming might be driving the recent “snow drought”. Decreasing snowpack and subsequent low streamflows will have adverse effects on ecosystem services, species abundances, and the resilience of the GYE.