Plants are actually powerful change agents on the planet’s surface. They pump water from the ground through their tissues to the air, and they move carbon in the opposite direction, from air to tissue to ground. All the while, leaves split water, harvest and manipulate solar energy, and stitch together hydrogen, oxygen, and carbon to produce sugars and starches—the sources of virtually all food for Earth’s life.
And in a study published in May, she investigated how U.S. forest die-offs would affect forests elsewhere in the country. In her models, she killed off forests in 13 heavily forested regions that the National Science Foundation has identified as being ecologically distinct. The results were dramatic. When she wiped out trees in the Pacific Southwest, forests in the Midwest and eastern United States suffered. In recent years, the Pacific Southwest has, in fact, lost an estimated 100 million trees, mostly to droughts and voracious insects.