Using Pollen Ratios as Indicators of Precipitation in the Eastern Deciduous Forests of North America

Keywords: Pollen, Precipitation, North America, Eastern Deciduous Forest, Paleoecology
Session Type: Virtual Poster Abstract
Day: Sunday
Session Start / End Time: 2/27/2022 03:40 PM (Eastern Time (US & Canada)) - 2/27/2022 05:00 PM (Eastern Time (US & Canada))
Room: Virtual 27

Abstract

Pollen records from lake sediment can directly provide valuable insight into vegetation composition throughout time. However, vegetation composition alone can only indirectly reconstruct the climate of a location. For this reason, many individuals compare pollen data with other proxies such as oxygen isotopes that reveal how climate varied during those time periods. Analyzing vegetation composition ratios and comparing them to other proxy data may reveal a trend between the pollen ratios and certain climate extremes. We examined eight pollen ratios and compared them to oxygen isotope data from the same core. Oxygen isotopes can be used to infer the precipitation levels of a location. We selected pollen taxa for the ratios by selecting ones that contrasted in moisture requirements in the modern day. Our evidence indicates that moisture may not have been the main factor driving the differences in amount of pollen per taxa. These findings suggest that other drivers, such as temperature, disease, insect pests or other disturbances could have had a greater influence on abundance of dominant tree taxa than moisture.