Exploring climate-growth relationships in limber pine (Pinus flexilis) from the Greater Yellowstone Area

Keywords: dendrochronology, pinus flexilis, forest decline
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

In the Greater Yellowstone Ecosystem (GYE), tree mortality is widespread and has been attributed to numerous stressors. In this study, we sampled limber pine (Pinus flexilis) to explore the species sensitivity to climatic variables and assess suitability for climate reconstruction. We developed a near centennial length chronology (1200-2020). We explore recent climate-growth relationships using daily, monthly, and seasonal data. We found a positive relationship with previous year’s January precipitation (r=0.2, p<0.05) and a negative relationship with previous year’s May maximum temperature (r=-0.2, p<0.05). We found partial correlations between climatic variables for variable season lengths. With the effects of maximum temperature removed, 6 month seasonal increments of precipitation were significant for the entire prior year (r>0.2, p<0.05). Daily climate data were assessed to identify significant climatic windows in time that may lie outside specific months on the Gregorian calendar, to provide better insight into the trees’ physiological requirements and responses. We assessed windows in time from 1-365 days. For precipitation, we found the previous year’s Sep. 21-Oct 3rd had the highest correlation with tree growth (r=0.56) and for maximum temperature, a single day (June 25th) in the summer prior had the strongest correlation with tree growth (r=-0.43). Our results show the species is sensitive to precipitation and that tree growth is highly dependent on the prior year’s conditions and highlight the importance of assessing climatic variables outside of human constructs of time and in a way that is biologically meaningful to the study species.