Climate change could make wet ecosystems act more like dry ones

By Nicholas Gerbis
Published: Monday, July 25, 2022 - 8:05am

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European Space Agency; CC BY-SA 3.0 IGO.
Satellite imagery shows the landscape in Denmark in a typical July in contrast to the dry, hot conditions with little vegetation in July 2018.

A new paper in the journal Nature Ecology & Evolution says global warming and drying trends can make wetter ecosystems act more like dry ones.

The authors argue ecosystem models need to reflect such possibilities.

Economists are fond of saying, "all things being equal." But complex systems are rife with feedbacks and exchanges that models don't always include.

Co-author Heather Throop of ASU's School of Earth and Space Exploration and School of Life Sciences said assuming the mechanisms that regulate cooler and wetter areas won't change as they dry could throw off ecological models.

"Maybe these wet systems — at some times, in some places — are going to be operating more like drylands, so we have to sort of consider those rules and add those kinds of patterns into our models," she said. 

Droughts and heatwaves can kill trees, reduce plant growth and lower biodiversity. But living things also adapt, meaning wetter areas can grow drier without necessarily becoming deserts.

Co-author Kevin Hultine, director of research at the Desert Botanical Garden, said, in some cases, adaptations might make ecosystems more resilient.

"You might find that rooting depth is deeper in some of these areas. That could actually buffer that ecosystem from really becoming more of a classic dryland," he said.

Traditional models would miss such outcomes.

Janne Hansen; CC BY-NC 4.0.
Corn in Denmark during the July 2018 heatwave.

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