Multiproxy evidence from caves of Native Americans altering the overlying landscape during the late Holocene of east-central North America

Abstract

We compare environmental changes recorded in stalagmites and alluvium from the mountainous Buckeye Creek basin of West Virginia, USA to a nearby, independent archaeological record of Native American presences in the forested watershed. A climatic record constructed from stable isotopic (δ¹⁸O _calc and δ¹³C_calc) and trace metal (Sr/Ca) ratios in stalagmitic calcite is consistent with regional palynology during much of the Holocene. The stalagmite δ¹³C_calc and Sr/Ca values track aridity associated with North Atlantic Ocean (NAO) ice-rafting events during solar minima. However, the δ¹³C_calc record diverges sharply from the Sr/Ca record at ~2100 (calendar) years BP, which maintains the same relationship with ice rafting in the NAO. A dramatic and sustained enrichment in δ¹³C_calc values (>1‰) without a corresponding shift in Sr/Ca values, suggests a systemic change in above-cave vegetation and soil carbon. This hypothesis is corroborated by a record of the stable isotopic composition of bulk organic carbon (δ ¹³C_org) in alluvial silts. Cultural artefacts record Native American presences in the watershed during the late Holocene and archaeologists place peak Native American presence as having occurred between 750 and 550 years BP, nearly contemporaneous with peaks in δ¹³C_calc , δ¹³C_org, and relative charcoal abundances documented herein. Notably, values of the three environmental proxies decrease after Native Americans abandoned the watershed. The available evidence is consistent with Native Americans having made significant changes to the area’s ecosystem and soils prior to the arrival of Euro-colonial peoples at ~225 years BP. Our findings highlight the active roles native peoples had in shaping the North American “wilderness” described prior to its destruction by early European settlers.