Devin Noordermeer's 1st First Authored Paper in Frontiers in Forests and Global Change

Devin Noordermeer MSc, from Ensminger Lab, publishes his first-authored paper in Frontiers in Forests and Global Change

Autumn Warming Delays the Downregulation of Photosynthesis and Does Not Increase the Risk of Freezing Damage in Interior and Coastal Douglas-fir

https://doi.org/10.3389/ffgc.2021.688534

Evergreen conifers transition from growth to dormancy during autumn via a process called cold acclimation, which is triggered in response to decreases in temperature and daylength. Climate change will cause warmer autumns, potentially disrupting cold acclimation. This disruption may impact the length of an evergreen conifers’ carbon uptake period as well as their ability to tolerate stressful winter conditions. These potential impacts are especially unclear for species with ranges that encompass diverse climates, such as Douglas-fir (Pseudotsuga menziesii). Our study investigated intraspecific variation in the effects of autumn warming on photosynthetic activity, photosynthetic pigments, and freezing tolerance in two interior (var. glauca) and two coastal (var. menziesii) Douglas-fir provenances. We exposed seedlings in growth chambers to conditions which simulated future warmer autumns and conditions which reproduced historical autumn temperatures. Our findings suggests that key components of cold acclimation, such as downregulation of photosynthesis, may be delayed in Douglas-fir under future warmer autumns, potentially leading to an increased carbon uptake period. Our findings also suggest that this will not likely come at the cost of impaired development of freezing tolerance. These findings have important implications on forestry breeding practices for Douglas-fir under changing climates.