The Driftless Cedars: A growing network of eastern redcedar chronologies in the Driftless Area of the Upper Midwest and the nascent Great Plains Drought Atlas

Keywords: Great Plains, dendrochronology, drought, tree rings, climate reconstruction
Abstract Type: Poster Abstract

Abstract

The highest agricultural production in the United States occurs in the Great Plains, a region subject to frequent drought often resulting in substantial environmental and economic impacts. Proxy tree-ring and lake sediment data suggest that the instrumental record of precipitation and soil moisture may not be representative of the natural variability over the past millennium. However, the mostly treeless Great Plains region lacks annually dated tree-ring chronologies, particularly prior to 1600 CE. This makes placing observed climate variability into a longer-term context challenging and adds considerable uncertainty to the available reconstructions of moisture anomalies for the region. Here, we present early results of a new collaboration seeking to develop millennial-length tree-ring chronologies bordering the Great Plains. These chronologies will enable development of a Great Plains Drought Atlas based on more local data than the currently available reconstructions. Leveraging research projects specifically designed to provide undergraduate students with authentic research experiences, we have developed two eastern redcedar (Juniperus virginiana) chronologies from living and remnant material that span 665 and 858 years in length. We have also identified numerous additional sites likely supporting ancient living trees and remnant wood. In addition to these redcedar chronologies, multiple dugout canoes made of oak have been recovered along the perimeter of the Driftless Area, with carbon dates ca. 1000–1200 CE, and are available for ring-width analysis. This creates the possibility of a millennial-length oak chronology to complement the eastern redcedar data and provide a multi-species perspective on past hydrologic variability.