Whitebark pine (Pinus albicaulis) Blue Intensity and Quantitative Wood Anatomy Methods Show Promise for Temperature Reconstruction for the Greater Yellowstone Ecosystem.

Keywords: Dendrochronology, Quantitative Wood Anatomy, Whitebark Pine, Pinus albicaulis
Session Type: Virtual Paper Abstract
Day: Monday
Session Start / End Time: 2/28/2022 03:40 PM (Eastern Time (US & Canada)) - 2/28/2022 05:00 PM (Eastern Time (US & Canada))
Room: Virtual 5

Abstract

Whitebark pine (Pinus albicaulis) populations are declining across southern Canada and northwestern United States. In the Greater Yellowstone Ecosystem (GYE), whitebark pine populations are negatively impacted by increased temperatures, decreased snowpack, and increased disease occurrence. The nutrient-dense seeds from whitebark pine support grizzly bear (Ursus arctos horribilis), Clark's nutcracker (Nucifraga columbiana), and Douglas squirrel (Tamiasciurus douglasii) survival and reproductive health. Understanding how whitebark pine respond to variable climate conditions is critical for the continued legacy of the whitebark pine ecosystem and its dependent and co-occurring species. Blue intensity (BI) is a new dendrochronological method such that blue light reflectance values from high resolution scans represent wood densities annually or intra-annually. Quantitative wood anatomy (QWA) is a novel dendrochronological method such that anatomical and cellular features are quantified and analyzed in micro-resolution quality. Our study uses both BI and QWA methods to measure BI values in whitebark pine (1600-2019) from the GYE and QWA parameters in whitebark pine such as maximum radial cell wall thickness (CWTRad), hydraulic conductivity (Kh), and lumen area (LA). Utilizing a soxhlet resin extraction process, which mitigated the common whitebark pine sapwood and heartwood color contrast issue that typically limits BI application, we found a strong summer (May-Aug) relationship between BI and maximum temperature (p < 0.01). With QWA methods, we found a strong subannual (Apr-Sep) relationship between CWTRad (p < 0.01) and maximum temperature. BI and QWA novel methods applied to whitebark pine show promise for a temporally and spatially strong temperature reconstruction for the GYE.