To survive climate change, plants can't just get up and move（在线收听）

To survive climate change, plants can't just get up and move

Transcript

As the climate gets hotter, plants may need to grow in new locations to survive. But the animals that help spread the seeds are disappearing.

RACHEL MARTIN, HOST:

Climate change is putting plants in a tough spot. Many are growing in places that won't be suitable as temperatures get hotter. And they can't exactly uproot and head elsewhere, right? Their seeds can move. But that's getting harder to do because the animals that help spread their seeds are disappearing.

NPR's Lauren Sommer reports.

LAUREN SOMMER, BYLINE: Understanding climate change means studying some tough questions. Ecologist Evan Fricke's specialty is knowing, when an animal eats a piece of fruit, how long it takes to come out the other end.

EVAN FRICKE: There's always this poop angle to my research - you know, Ph.D. in bird poop, basically.

SOMMER: Why is that important to climate change? - because of the deal that's been struck between animals and plants. Plants need to spread their seeds, but they can't really move. So they put them inside delicious fruits that animals eat. The animals get a snack, and plant seeds get a ride.

FRICKE: It hangs out in that digestive tract for minutes to hours for most plant species and then gets deposited somewhere else.

SOMMER: Birds might take seeds just a few feet. An elephant can take a seed miles. There's even some thought that some fruits are constipating so the seeds get an even longer ride inside the animal. And right now is a crucial time for seeds to move. Climate change is making ecosystems hotter or drier - no longer a good fit for the plants that grow there.

FRICKE: The areas that are suitable for growth, survival, reproduction are basically moving. And so the plants need to, quote-unquote, "migrate" to keep up with the changing climate.

SOMMER: But just when plants need them, birds and animals are declining due to hunting, habitat loss and extinction. As a researcher at the University of Maryland and Rice University, Fricke and other colleagues wanted to find out how that would affect plants globally. In a paper out in the journal Science, they found there's a 60% decline in the ability of plants to move with climate change.

FRICKE: If they're unable to do that, that means that certain plants might disappear from our forests and other ecosystems.

SOMMER: Fricke says this is already playing out because larger animals, which move seeds farther, have declined the most. In an ecosystem, one change can have cascading impacts.

FRICKE: It highlights that there's this tight link between the biodiversity crisis and the climate crisis.

SOMMER: That complex relationship is on the cutting edge of research, says Noelle Beckman, an ecologist at Utah State University who wasn't involved in the study. With climate change, plants can't be studied in a vacuum.

NOELLE BECKMAN: They're experiencing all these different changes, from climate change to their seed dispersers being potentially hunted out or lost to habitat loss.

SOMMER: That has some scientists looking at ways to help plants move. It's known as assisted migration - basically planting seedlings in places that will be better for them in the future climate. But at the very least, Beckman says, this research shows that conservation shouldn't just be about protecting the things in an ecosystem, but the relationships between them.

Lauren Sommer, NPR News.