Termites Protect Tropical Rainforests During Droughts

The insects get a bad rap, but in a Borneo rainforest “they’re like ecological insurance”

Trees, some of the tallest in the world, towered above Hannah Griffiths and her colleagues each morning as they tramped deep into a pristine patch of rainforest in the Maliau Basin in Borneo. Birds sang and wildlife ambled across their paths. One day, a sun bear skittered across the path in front of them. Another day, a king cobra slithered by.

But the scientists walked past, crossing suspension bridges and pushing deeper into the forest, where they had set up a set of experiments to look at the ecological effects of smaller, less flashy creatures: termites.

Termites, they knew, ruled the realm of the dirt in the forest, chomping through the drifts of leaves that fell from the trees, digging tunnels and aerating the soil, and “engineering” throughout the ecosystem. But they didn’t know exactly how important the insects were to keeping the forest healthy and functional—so they had set out to tease out their role by removing termites from a particular spot in the forest and seeing how it responded.

As luck would have it, they started their experiment when the forest was gripped by an extreme drought, during the 2015-2016 El Niño event. And what they found—summarized in a paper published Thursday in Science—was unexpected: termites were everywhere—nearly twice as many as during a normal rain year. And those termites helped the forest to withstand the drought intact and healthy: in the termite-rich areas, the soil stayed moist, more tree seedlings sprouted, and the system hummed along despite the long, hard dry spell.