Soil Chemistry in Drylands to Change as Climate Become More Arid

Levels of soil nutrients are likely to become imbalanced as the world's drylands become even drier, potentially affecting the lives of more than a billion people, according to a new study.

Researchers from Northern Arizona University -- which is itself in a particularly dry, dusty location -- suggest that an increasingly dry climate may have a variety of effects on soil compositions.

Matthew Bowker, assistant professor of forest soils and ecosystem ecology, said that most of the 17 essential nutrients plants need to grow are soil resources, including nitrogen and phosphorous.

By running a statistical climate change model, Bowker was able to predict how soils will respond to climate change, focusing on what happens as soils in dry areas dry out further.

One of Bowker's finds was that as the climate become more arid, nitrogen will decrease and phosphorus will increase.

"Both are essential for plant growth, and both are typical components of fertilizer, but both need to be around in the right quantities for plant growth to proceed most efficiently," Bowker said.

"It's like a situation where you're making hamburgers but run out of beef. You can't just slip in another bun and still produce a hamburger."

The effects have the potential to be profound in drylands, which cover 41 percent of the Earth's surface. One-fifth of the world's population lives on drylands.

Bowker suggests that people who derive their livelihoods from arid ecosystems will become increasingly strained as a drying climate will lessen available local resources, as well as cause more dust storms.

"We can probably expect more and more dust in the air," he said.

Boweler's work in Arizona was part of a larger effort by a team of scientists, who traveled to 224 locations in 16 countries on every continent but Antarctica. Bowker led one of the sampling teams, which visited 10 study sites in northern Arizona and Utah. Those sites ranged from dry, grassy shrublands with low precipitation to relatively wet sagebrush ecosystems.

"This is a testament to the power of networked science," Bowker said, adding that it would have been "prohibitively expensive" for any one researcher or research group to complete the project.

The results of the study are published in the journal Nature.