YELLOWSTONE NATIONAL PARK, Wyo. — This is a tale of two forests, Densetown and Stumptown, whose paths diverged after a succession of wildfires. One illustrates the historic resilience of the dense Yellowstone pinelands; the other portends a much sparser future for these forests under climate change.

Seventeen years ago, fire swept through this area north of Jackson Lake and Grand Teton’s glaciered peaks, burning a forest of old-growth lodgepole pines that had towered for more than 200 years. In its aftermath, a new generation of pines sprouted, healthy and dense.

Then last year, wildfire again roared through. Thanks to the vagaries of wind and terrain, one thick section of the forest was untouched. A neighboring plot of trees was reduced to singed stumps and ashen pine skeletons. A crew of scientists here this summer studying the forest’s regrowth nicknamed the sections Densetown and Stumptown.

Their findings on how forests respond to fire will help guide forest management and firefighting policies as a warming climate contributes to more frequent wildfires. Fires are now raging across the West, from Southern California to Glacier National Park, with experts predicting that 2017 will go down as one of the worst wildfire seasons in decades.