Where Animals and Plants Might Survive Climate Change

Scientists are searching for pockets of ecological resistance in the face of climate change, places that seem to be warming less quickly than others due to unique natural conditions.

The hope is that as the earth continues to get hotter, these “climate refugia” could serve as strongholds for plants and animals

For a decade, scientists have been studying this phenomenon in a steep mountain valley in the Sierra Nevada. Devils Postpile National Monument is known for its distinct geologic formations, where the crumbling columns of rock from an ancient lava bed resemble, well, a pile of posts.

But when Deanna Dulen began working there almost 20 years ago, she noticed something else.

“It was even colder than I ever anticipated,” said Dulen, who is now superintendent of the monument. The chill was especially noticeable on the floor of the valley, which was colder than the peaks thousands of feet above it.

“That’s the opposite of what you’d expect,” she said. “Usually you expect as you go up in elevation, it will be getting colder.”

Dulen began working with several scientists to investigate. After installing dozens of temperature sensors around the valley, they discovered it undergoes “cold air pooling,” a phenomenon that keeps a mass of cool air sitting on the valley floor for about half the day.

It happens thanks to the Postpile’s special topography. The valley is aligned north-south, surrounded by high granite walls, which block the sunlight and cast huge shadows across the valley floor.

“In the morning it stays shadier in the valley much later, and then it gets shadier earlier in the afternoon,” Dulen said. “That shade helps to make it cooler.”

The cold air also gets trapped, especially in the Soda Springs meadow, where the granite walls come together at one end, leaving only a narrow opening for the air to escape.

“Essentially that cold air bottlenecks up,” Dulen said. In the early morning, the meadow can be 18 degrees cooler than locations just a few hundred feet above.

Dulen and her colleagues realized that this effect could prove particularly important in a warming climate. From her time working in Alaska, Dulen knew about “paleoclimate refugia,” the spots that remained relatively free of ice during the last ice age, allowing plants and animals to endure.

Devils Postpile could be a modern “climate refugia,” she thinks, where plants and animals would be somewhat buffered from the effects of rising temperatures. That’s especially important for mountain meadow habitat, which supports a huge number of Sierra Nevada species.

“We’re very concerned about the impacts of a warming climate,” said Dulen. “We have a very high concentration of biodiversity here. We actually have 400 species of plants in just 800 acres; a hundred species of birds.”

Dulen says knowing where climate refugia are can help land managers conserve them. The park service is looking at protecting Soda Springs meadow by keeping out invasive species and making sure the forests around it don’t become overgrown and fire-prone. She may also have to defend against “conifer encroachment,” where pine trees invade mountain meadows in search of water in a hotter, drier climate.

Dulen says knowing where climate refugia are can help land managers conserve them. The park service is looking at protecting Soda Springs meadow by keeping out invasive species and making sure the forests around it don’t become overgrown and fire-prone. She may also have to defend against “conifer encroachment,” where pine trees invade mountain meadows in search of water in a hotter, drier climate.

“There’s no easy answers, but it’s the challenge that we’ve been called to do, and it’s part of working for the National Park Service,” she said. “Parks are living labs for understanding our natural world and how to become better stewards so we can have this for our generation and future generations of all species.”

Dulen is hopeful their efforts will become a model for finding other climate refugia. Initiatives are already underway in Acadia National Park in Maine, where researchers have mapped climate havens for 30 different plants and animals.

“There’s urgency in identifying these places so we can protect them,” said Toni Lyn Morelli, who led the work in Acadia and is a research ecologist with the U.S. Geological Survey at the Northeast Climate Adaptation Science Center in Massachusetts.

Given how fast the climate is changing, though, scientists believe refugia can protect plants and animals for only so long.

“We know there are clearly limits,” she said. “In one sense, this is just buying time for us as a society to come up with better solutions and stop climate change.”

Still, Morelli says, climate refugia could be an important strategy for land managers to lessen climate impacts.

“I feel like it gives people some hope. Or at least something positive to focus on. I think climate change is really hard to think about and to be experiencing. And it’s especially hard for natural resource managers to be responsible for.”

This story is part of KQED Science’s partnership with Covering Climate Now, a global collaboration of more than 300 news outlets to strengthen coverage of the climate story.