Assessing the climate feedbacks of U.S. Southwestern dryland forests and woodlands.

Like other dryland regions around the world, the U.S. Southwest is on a steep trajectory towards a hotter and drier climate. Among the most conspicuous effects of this drying are large-scale vegetation transitions towards sparser systems and lower growth forms. Such structural transformations will have far-reaching consequences for ecosystem functioning and for the climate feedbacks of dryland vegetation. These feedbacks remain undervalued and understudied in a climate mitigation context, because drylands sequester less carbon per area compared to more mesic systems. This neglect is unfortunate, because – due to their sheer extent – global drylands amount to about 22% and 38% of the global above- and belowground carbon pools. There is thus urgent need to better understand and quantify the spatiotemporal variability in the carbon, water, and energy budgets of these systems. And because broad-scale remote sensing and vegetation modelling still struggle with persistent limitations in drylands, developing robust and scalable ground observations along environmental gradients is key. In this talk, I outline opportunities for enhancing ecological networks by integrating tree-ring data with ground and airborne remote sensing. I also discuss opportunities for the resulting spatiotemporal information to benefit nature-based climate solutions in the U.S. Southwest and elsewhere.