This time of year, the sun never sets in Noatak National Preserve, a park protecting the Noatak River and its surrounding forest and tundra in northwest Alaska. Researchers have observed the forest in Noatak expanding northward into tundra; elsewhere, like in Yosemite National Park, forests have moved upslope into higher mountains. As the climate continues to warm, we’re studying these high-latitude and high-elevation ecosystems with particular interest. How different might these ecosystems look in another 50 years, and which plants and wildlife will successfully adapt?