Plants and animals living in the Rocky Mountain West could face bigger challenges than previously expected as global temperatures rise, according to a new study by the University of Montana.
Its lead author, Solomon Dobrowski, an associate professor of forest landscape ecology, said as climate change makes their current homes inhospitable, both wildlife and plant life will face four options.
"Basically as the earth warms, if you're a plant or an animal living in Jackson Hole, Wyoming, you're going to have to either adapt to those changes; you'll have to tolerate those changes; you'll have to move or you'll go locally extinct," he said.
Because mountain areas contain multiple micro-climates, scientists had predicted organisms living there wouldn't have to travel far to find cooler habitats. But Dobrowski's research found even short migrations could expose plants and animals to potentially life-threatening variations in temperatures, moisture and soil quality.
He explained the complexity of mountain topography creates variable climates close together, which is one reason they support roughly one-quarter of the planet's biodiversity, and are home to nearly half of the world's biodiversity hotspots.
Dobrowski said those variances also pose risks, however.
"So, if you think about moving from one mountaintop to another mountaintop, you often have to traverse a very warm valley in between," he explained. "And organisms, through time, that warm valley may preclude them from actually being able to migrate and keep pace with climate change."
He noted Rocky Mountain states are already seeing some impacts of climate-related migration. He cited the disappearance of white-bark pine, a prominent food source for grizzlies, as one reason bears have moved to lower elevations in search of food, increasing their contact with people.