Master of Arts, The Ohio State University, 2019, Geography

The goal of this research is to develop a new proxy record sensitive to water availability in the tropical Andes, where climate change threatens glacial reserves of water stored as ice. As such, this study constitutes the first investigation into the radial growth of the newly described tropical tree species, Polylepis Rodolfo-vasquezii. In the dry season of 2017, a sample set of cores were extracted from a P. rodolfo-vasquezii montane forest in the Cordillera Huaytapallana in the central Peruvian Andes. Standard dendrochronological techniques were applied to the samples to produce a 77 year-long annually resolved chronology, from 1940 to 2016. Correlation analysis between tree ring widths and station data as well as regional anomalies and reveal that P. rodolfo-vasquezii is sensitive to wet season precipitation and discharge from the nearby Shullcas River. The strongest relationship with the tree rings was late wet season discharge. Based on these correlations, the first-ever monthly and seasonal discharge reconstructions were produced for the Shullcas River. The calibration-verification statistics for each model indicate that there are varying degrees of predictive skill in the reconstructions produced. The optimal reconstruction was for the average of April-May discharge. This work provides evidence that Polylepis rodolfo-vasquezii is a useful species for dendrochronological research and highlights its relationship to moisture in the Cordillera Huaytapallana.

Committee: Bryan Mark PhD (Advisor); Alvaro Montenegro PhD (Committee Member); Ellen Mosley-Thompson PhD (Committee Member) Subjects: Environmental Science; Geography; Hydrologic Sciences; Paleoclimate Science