Teaming Up with Termites

They are about the size of a Tic Tac. They have no eyes and a see-through gut. They eat poop and farm fungi. And they might be our best allies in the fight against desertification. Who are these climate change warriors?

Termites! Yes, that same lowly insect that likes to chew through the back deck. According to a new report published in the February issue of Science, these critters and the mounds they create are crucial to the resilience of savannahs and other dryland ecosystems across the planet.

“Termite mounds are islands of fertility,” says Robert Pringle, an ecologist at Princeton University and study coauthor.

When you think of termite mounds—if you think of them at all—you might imagine a tall dirt tower, as high as 25 feet. But beneath the ground, the colony can stretch for another 30 feet or more. Termites can survive in extremely dry places, Pringle says, but when it does rain, their subterranean tunnels allow water to penetrate the soil. This encourages vegetation to take root, creating a refuge for other insects, mammals, and birds. Even when the rest of the savannah has withered and died, the mounds remain, like green polka dots on a ruddy field.

But no oasis can survive indefinitely. If cut off from rain for too long, even these dirt dwellers and their entourage will shrivel up and croak. According to the United Nations, nearly 30 million acres are lost to drought and desertification each year, and climate change will likely make it worse. (It’s such a big deal that the U.N. created a special convention to combat desertification.)

Every dryland ecosystem has a certain threshold before it becomes desert, says study coauthor Corina Tarnita, who is also a Princeton ecologist. What’s interesting is that termite colonies significantly alter the amount of drought the savannah can withstand. “The termite mounds prolong the life of that system,” she explains. “And they also make it a lot easier to bring the system back once you’ve lost it.”

Like ants, termites gather refuse and hoard it below. So even if the colony dies, when the rains return, stockpiles of subterranean seeds lay primed and ready to sprout. In this way, every termite mound is a savannah starter kit—just add water.

Pringle and Tarnita traveled to Kenya for their study, but their termites—those of the genus Odontotermes—can be found throughout the Paleotropics. And that’s good news, because more than 41 percent of the earth’s landmass is considered “drylands.”

According to the International Union for Conservation of Nature, drylands are home to one-third of the world’s population and 28 percent of endangered species. For the inhabitants of such places, where a few inches of rain can mean the difference between life and death, climate change is no mere talking point.

Last year was the hottest since temperature records began in 1880. And as the mercury rises, so do the frequency and severity of droughts.

As the global desertification problem gets worse, it will become increasingly important to develop early warning systems in order to identify ecosystems on the brink of collapse. And these termite findings change a lot of what we thought we knew.

You see, when drylands tip over into the desert category, they tend to do so in a series of easily identifiable patterns. From above, you see the vegetation start to break up and form gaps. Those gaps widen into what Tarnitas describes as a labyrinth pattern. The labyrinth then turns to spots. Finally, if the drought persists, all these gradual patterns give way to what’s called a “catastrophic shift.” The spots disappear, along with all normal savannah life. The final phase of desertification is complete.

Before Pringle and Tarnita’s study, the thinking was that the spot phase indicated that an ecosystem was perilously close to a catastrophic shift. That’s still true, if the spots you see are the last of the green clumps. But if termites are in the area, guiding the arrangement of the flecks of vegetation, the diagnosis is a little less brutal.

“It’s not like the road is now rosy, and everything is perfect,” says Tarnitas. “But if there are termites, then at the very least we know we have an ally in those systems.”

In addition to helping us learn the patterns of the drylands, the dirt devils may yield other secrets. For instance, it may be possible to mimic the way the mounds retain water and deploy this technology in areas without the benefit of termites.

After all, until our world leaders can agree on meaningful ways to address climate change, perhaps a bunch of blind, poop-eating invertebrates can pick up their slack.