Elevation‐Dependent Hydroclimatic Constraints on Millennial Growth of Pinus flexilis Across Its Ecological Amplitude in the Greater Yellowstone Ecoregion
Lily Stroud, Maia Cuddy, Grant L. Harley, Matthew F. Bekker, Karen E. King, R. Stockton Maxwell, Joseph Pettit, Zachary W. Foley, Richard Thaxton, Nick Koenig, R. Justin DeRoseABSTRACT
Aim
We tested how climate–growth relationships, temporal coherence and responses to compound climate extremes vary across a regional elevational gradient occupied by
Location
Greater Yellowstone Ecoregion, northwestern Wyoming, USA.
Time Period
Dated tree‐ring material spans 514–2020
Major Taxa Studied
Limber pine (
Methods
We developed three millennial‐length ring‐width chronologies from high‐, mid‐ and low‐elevation sites. We compared radial growth with instrumental and reconstructed climate, quantified shared and elevation‐dependent growth patterns using PCA and moving‐window analyses, and evaluated growth responses to compound hot‐dry and cool‐wet extremes.
Results
Growth at all elevations was moisture sensitive and declined during warm summer conditions, indicating that heat amplified water limitation across the gradient. The chronologies shared a broad hydroclimatic signal, but the high‐ and low‐elevation sites often differed in growth magnitude and in the timing of growth responses. High‐elevation Wolf Knob temporarily decoupled from the dominant growth pattern during cool Little Ice Age conditions, whereas low‐elevation Outlaw Ridge showed the most persistent growth suppression following hot‐dry extremes.
Main Conclusions
Across the sampled ecological amplitude in the GYE,