137-9 Land-use and climate change in the early 19th century associated with European Settlement inferred from lake sediments and tree rings, Northeast Ohio

Session: Joint SGD-SEPM-IAS Focus on the Sedimentary Record of Climate Change

Presenting Author:

Greg Wiles

Authors:

Wiles, Greg C.¹, Lyon, Eva C.², Wilson, Mark A.³, Lowell, Thomas V.⁴, Diefendorf, Aaron C⁵, Corcoran, Megan C.⁶, Cook, Edward R.⁷, Wiesenberg, Nicholas C.⁸, Landis, Joshua⁹

Abstract:

Lake and tree ring records used to reconstruct land use and climate changes underscore the convergence of natural and anthropogenic forcings during the early decades of the 19^th century in Northeast Ohio associated with European Settlement. Forcings during this interval of the Little Ice Age include volcanic events (e.g., 1809-10, 1815-16 CE) and decreased solar variability (Dalton Minimum) along with regional anthropogenically forced hydroclimate disruptions associated with deforestation, draining wetlands, and conversion to agriculture.  Additionally, surface albedo changes with deforestation along with a marked increase in dust were active through the interval.

Two, meter-long sediment cores recovered from Browns Lake in Northeast Ohio are dated with Pb-210, Cs-137 and C-14, and exhibit a clear and abrupt increase in clastic input dating to the early decades of the 19^th century consistent with the timing of European Settlement in the watershed. Tree-ring records from old growth white oaks in the watershed show a marked growth release about 1820 CE supporting the radiometric dating. Hydroclimate for this interval is reconstructed using a well-verified summer drought record based on white oak ring width series showing two decades of drying centered on ~1810 CE consistent with the tree-ring based North American Drought Atlas. This drying co-occurs with cooling, and is supported by other lake and bog investigations from the Midwest that suggest low lake levels coinciding with a positive phase of the Pacific North American Pattern (PNA).  These cool, dry conditions are likely exacerbated by the land use transition and associated changes in albedo, hydrology, and increases in dust along with a negative shift in the Pacific Decadal Oscillation. The most recent lake sediments, laid down in the last several decades, show a recovery from the clastic flux back to pre-Settlement organic-rich muds likely reflecting changing agricultural practices, encroachment of trees and shrubs into the surrounding bog, and a regional increase in precipitation. Further study of this pre-industrial to modern transition can help parse out the relative roles of natural and anthropogenically-forced climate variations in the region.

 

 

 

 

 

 

Geological Society of America Abstracts with Program. Vol. 57, No. 6, 2025

doi: 10.1130/abs/2025AM-7849

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