How does drought kill?

The physiological mechanisms of climate-induced forest mortality

Climate change is predicted to have immense and far-reaching effects on the world’s forests. Massive forest die-off has been documented recently across several North American tree species, often linked to global climate change type droughts. Such mortality events could lead to dramatic decreases in carbon stored by forests and severely affect animal populations and local economies dependent on tourism and logging.

Trembling aspen (Populus tremuloides) is the most widespread tree species in North America. A recent and severe aspen mortality, termed sudden aspen decline (SAD), has swept across Colorado, several other western states, and parts of Canada. The die-off has escalated dramatically in the last six years to around 553,000 acres in Colorado alone.

We currently lack knowledge of the fundamental physiological mechanisms of how climate change will affect trees, which hinders our understanding the causes of SAD and predicting the effects of climate change on forests. Integrating the disciplines of plant physiology, ecology, and climate science is necessary to understand and predict climate change’s impacts. My research seeks to fuse these disciplines to provide novel and rigorous ways to assess and predict the impacts of climate change on forests.