Amazonian Wetland Domestication: A Spatial Analysis of Pre-Columbian Fish Weirs in Lowland Bolivia

Lisa Garcia, MS Student

Biology
Mentors: Felisa Smith and Scott Collins

Paleomiddens are piles of debris created by woodrats which under the right conditions can persist for many tens of thousands of years.

The contents within these middens provide unique historical ecological records, giving a window into past ecological dynamics. Can they be used to infer climate?

This study aims to understand local climate from 34,000 to 8,000 years ago by using carbon (δ13C) and nitrogen (δ15N) stable isotopes from Juniperus osteosperma leaves found in bushytailed woodrat (Neotoma cinerea) paleomiddens, collected from Titus Canyon in Death Valley National Park California.

Preliminary results reveal that δ13C stayed remarkably consistent, and δ15N increased over time in the paleomidden samples. To put these data into modern context, juniper was collected along an elevational gradient around Moab, Utah.

These modern data reflect variation in δ13C and δ15N values, with a substantial decrease in nitrogen isotopic values compared to the paleomidden samples.

These results led to an additional isotope analysis of a juniper specimen collected from Death Valley and held in the Reno herbarium.