Speaker: Evan Larson, Professor of Environmental Sciences and Society, UW–Platteville
Ancient trees carry stories of climate and environmental change, rooted to place, that can help us to understand the past in order to better predict and prepare for the future. In the field of tree-ring science, or dendrochronology, enthusiasts are quick to celebrate the longevity of western species like giant sequoias, redwoods, and bristlecone pine, or eastern species such as bald cypress. These trees are magnificent for their stature, twisted growth on windswept slopes, or massive buttresses in inaccessible swamps and backwaters; their longevity makes sense. Yet as researchers crisscrossed North America in search of long tree-ring records, few took the winding backroads of the Driftless Area, where pockets of centuries-old eastern redcedar trees humbly resided among the outcrops and bluffs along nearly every meandering stream and river that shaped the land. This talk will share how a decade of undergraduate research at the University of Wisconsin-Platteville worked first with prairie oaks, then with eastern redcedar, to create a network of tree-ring data that spans the past millennium and is now providing annually-resolved insights on a suite of hydrologic variables, from drought and groundwater elevations in southwest Wisconsin, to rainfall over the Corn Belt, to a nascent gridded drought reconstruction that will span the Great Plains. Within the information about past climates carried by these trees are woven the influences of shifting culture and land use, with implications for how we approach ecological restoration in the Midwest. Linked with other tree-ring collections developed by UW-Platteville students, the potential for a Wisconsin paleohydrology atlas is emerging.