Disentangling climate persistence from ecological memory in tree-ring records

Keywords: dendrochronology, ecology, memory
Session Type: Virtual Paper Abstract
Day: Monday
Session Start / End Time: 2/28/2022 09:40 AM (Eastern Time (US & Canada)) - 2/28/2022 11:00 AM (Eastern Time (US & Canada))
Room: Virtual 41

Abstract

The legacies of drought are evident in tree-ring records as strong temporal trends over multiple years. From a physiological perspective, these trends represent lasting damage to woody tissues, loss of leaves, and depletion of stored sugars, all which take multiple years to recover. However, instrumental records of drought also exhibit strong temporal autocorrelation across years. Soil moisture conditions evolve over the course of months to years in response to sustained precipitation deficits. Because tree rings integrate both physiological and climatic signals over time, it is possible to misattribute sustained drought to biological memory. We analyzed a network of moisture-sensitive tree-ring chronologies from the eastern slope of the Rocky Mountains alongside climate records and remotely-sensed observations of ecological productivity to determine which records exhibited the highest degree of temporal autocorrelation. We found that drought records were the most persistent over time, contrary to expectations if biological carryover exceeded underlying dry conditions. Our results suggest that active responses to sustained drought dominate growth patterns of trees from this region.