Plant Production Declines in Drylands as Climate Change Impacts Soil

As our climate shifts, drylands in the world are becoming even drier. Water isn't the only resource that will come in short supply, though; the levels of nutrients in the soil will also likely be affected. Now, scientists have found that as the climate changes, plants could experience a decline which could affect the lives of one-fifth of the world's population.

Drylands are defined by predominantly lower levels of moisture. They cover about 41 percent of the Earth's surface and if conditions were to change, those who depend on these ecosystems for crops, livestock forage, fuel and fiber would be drastically impacted.

Most of the 17 nutrients that plants need to grow to their potential are soil resources, such as nitrogen and phosphorus. Yet as the climate changes, the proportion of these nutrients also changes. In order to find out exactly what changes might occur, though, the researchers developed a statistical model.

So what did they find? It turns out that as the climate becomes more arid in regions such as Arizona, nitrogen will decrease and phosphorus will increase. This could spell some real problems for plants in the future.

"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," said Matthew Bowker, one of the researchers, in a news release. "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."

As plants decline, it's likely that more would be at stake than just crop failure. In Arizona, the projected decrease in plant production could magnify the impact of dust storms.

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

The findings are important for understanding exactly how drylands will be impacted by a shifting climate. If the soil nutrients do change, then farmers and residents in these regions will likely have to learn how to cope with the lack of plant cover.

The findings are published in the journal Nature.