Dwindling Winds from Climate Change May Tip Predator-Prey Balance

Could changes in the wind upset the balance between predator and prey? That just might be the case. While rising temperatures and shifting precipitation may get most of the attention, climate change can also impact wind patterns which, in turn, could alter predator-prey relationships.

"There are all sorts of other things that are changing in the environment that affect animals and plants and their interactions," said Brandon Barton, one of the researchers, in a news release. "My students and I were standing out in a cornfield on day as big gusts of wind came by, and the corn stalks were bending almost double. From the perspective of an animal living in the corn, we thought, 'That's got to have a big effect.'"

Currently, researchers estimate that wind speeds in the Midwest will decline as much as 15 percent during the 21^st century. This is due to the fact that Earth's poles are warming faster than the equator and are robbing the atmosphere of some of the temperature differential that creates the wind. In addition, buildings create barriers to the wind.

In order to better understand the effects on predator-prey relationships, the researchers took a look at lady beetles. These beetles eat a major soybean pest: the soybean aphid. The researchers grew plots of soybeans in alfalfa fields; while some were protected with wind blocks, the others were left in the open.

In the end, the scientists found that there were two-thirds more lady beetles in the plots hidden from the wind. There were also twice as many soybean aphids on the plants growing in the open. The wind had to direct effect on the aphids since they were so tiny, but did have an effect on the beetles.

So what does this mean? Slower natural wind speeds may actually reduce the amount of pesticides needed to keep soybean aphids from wrecking harvests. In addition, this research presents other opportunities for pest control.

"By growing trees or not harvesting them around a field, you may be able to have an indirect effect on the number of aphids on your soybean plants," said Barton. "The mechanism may be different for other predators, but it's not hard to start thinking about the effects. Think of a wolf or coyote. Larger predators hunting by scent-and the prey trying to detect their predators-may be affected by less wind moving scents around."

The findings are published in the journal Ecology.