Ancient Ghost Forests Reveal how Alaska’s Glaciers and Cedar Trees Responded to Past Warming Events

DESCRIPTION: This project focuses on the collection and processing of recently-exposed series of ancient cedar forests were being exhumed from the retreating La Perouse glacier in Southeast Alaska. The most northerly stand of climate-driven Alaska Yellow cedar (Callitropsis nootkatensis) decline occurs just outside the La Perouse glacier’s former limit. The leading hypothesis for this cedar decline is an increase in winter thaw events has lead to the loss of an insulating snowpack that leaves cedar roots vulnerable to subsequent frost. By using dendrochronology we will uncover the calendar dates and duration that the glacier was less extensive, and date when it started to advance, killing the forests. In addition, we can date when the standing cedar trees outside the glacier limit began dying due to climate change.