The trees were not coming back. In the years following the 2000 Walker Ranch Fire, Tom Veblen, a forest ecologist at the nearby University of Colorado, Boulder, saw that grass and shrubs were regrowing in the charred foothills, but he had to search to find the rare baby version of the tall ponderosa pines that had dominated the area before the fire.
“I kept watching and I was barely seeing any seedlings at all,” Veblen said.
One of his graduate students at the time, Monica Rother, who now leads her own lab at the University of North Carolina at Wilmington, took a closer look, formally sectioning off research plots and returning year after year to count little trees. More than a decade after the Walker Ranch Fire most of her plots had zero tree seedlings.
Now that the winter has cooled the 2021 fire season, scientists are looking at the big burn scars across the West with the grim understanding that, in some places, the pine and Douglas fir forests will not return.
The driving force here is that the rising global temperature is wiping out seedlings. In many spots around the U.S. West, summer temperatures are already high enough to co... Read more