For many species, climate change brings switches in their niches

By David Frey

Over the past four decades, Finland’s climate has changed substantially, with increasing temperatures and a shorter duration of snow cover. Credit: Laura Antão

It’s tempting to think of climate change as something looming in the future. But scientists have already collected decades of data showing warming temperatures, changing ecosystems, and wildlife moving and trying to adapt to new environments.

But less is known about how climate change is affecting species’ ecological niches—the ranges of temperatures and other environmental conditions that they tolerate. For some species, like those that rely on ice and snow, warmer weather is pushing them into less optimal conditions. Others, at the northern edge of their range, may benefit.

“More and more, people know that climate change is here. The evidence is piling up,” said Laura Antão, a postdoctoral fellow at the University of Helsinki. Antão is a lead author of a study published in Nature Climate Change looking at how a warming climate is causing species in Finland to “reshuffle” between more beneficial and less beneficial parts of their niches.

Her team looked at four decades of data for almost 1,500 species—from phytoplankton to mammals—a feat only possible thanks to long-term monitoring records in the country.

They weren’t looking at how species were moving to different areas to keep up with climate change—although they knew that was happening. Instead, they set out to model how species were shifting within their climatic niche. Were conditions becoming more optimal for them? Were they becoming more extreme?

What they found, Antão said, is that “there is a lot of shuffling going on.”

Finland was a good place to look, she said. Climate change is happening two to three times faster in the northern polar regions than elsewhere in the globe, creating both winners and losers among species.

The researchers found that species in the northern part of the country, like birds, often benefited from warming temperatures, finding themselves in a more optimal part of their niche. Others, like butterflies in southern Finland, already live in optimal conditions and only stand to lose as temperatures become even warmer. That’s probably true for other insects, too, she said, which often can’t adjust as change their behavior as easily as mammals to adapt to changing conditionds.

“Some of these species are migrating to the poles. Some are migrating to mountain summits. At some point, there is no other place,” Antão said.

But even for species that seem to be benefiting from warmer temperatures, climate change may bring other costs. If their ecosystem gets disrupted—say a critical plant disappears, or there’s not enough prey to feed a predator—it can cause ramifications throughout the ecosystem.

“These interactions—these partnerships—are fundamental,” Antão said. “There is an expectation that if we start to push some of these species too far, there might be this cascading effect.”

Antão considers this research a first step toward better understanding how species respond to climate change, predicting how they may respond in the future and preparing lower latitudes for what’s to come.

“This can be a cautionary tale for other places,” she said. “Changes will happen. Maybe not as fast, but they will come.”

David Frey is managing editor at The Wildlife Society. Contact him at dfrey@wildlife.org with any questions or comments about his article. Read more of David's articles here.

You can follow him on Twitter at @davidmfrey.


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