Termite mound paradises help buffer African dry land against climate change

• Can hold back deserts by creating oases of plant life

TERMITE mounds may help protect arid landscapes in Africa from turning into deserts as climate change exacerbates droughts.

      The results of a new study not only suggest that termite mounds could make these areas more resilient to climate change than previously thought, but could also inspire a change in how scientists determine the possible effects of climate change on ecosystems.

     Termites might not top the list of humanity’s favorite insects, but new research suggests that their large dirt mounds are crucial to stopping the spread of deserts into semi-arid ecosystems and agricultural lands. The results not only suggest that termite mounds could make these areas more resilient to climate change than previously thought, but could also inspire a change in how scientists determine the possible effects of climate change on ecosystems.

     In the parched grasslands and savannas, or drylands, of Africa, South America and Asia, termite mounds store nutrients and moisture, and — via internal tunnels — allow water to better penetrate the soil. As a result, vegetation flourishes on and near termite mounds in ecosystems that are otherwise highly vulnerable to “desertification,” or the environment’s collapse into desert.

      Princeton University researchers report in the journal Science that termites slow the spread of deserts into drylands by providing a moist refuge for vegetation on and around their mounds. They report that drylands with termite mounds can survive on significantly less rain than those without termite mounds. The research was inspired by fungus-growing termites of the genus Odontotermes, but the theoretical results apply to all types of termites that increase resource availability on and/or around their nests.

       Corresponding author Corina Tarnita, a Princeton assistant professor in ecology and evolutionary biology, explained that termite mounds also preserve seeds and plant life, which helps surrounding areas rebound faster once rainfall resumes. “The rain is the same everywhere, but because termites allow water to penetrate the soil better, the plants grow on or near the mounds as if there were more rain,” Tarnita said.

     “The vegetation on and around termite mounds persists longer and declines slower,” she said. “Even when you get to such harsh conditions where vegetation disappears from the mounds, re-vegetation is still easier. As long as the mounds are there the ecosystem has a better chance to recover.”

      Jef Huisman, an aquatic microbiology professor and theoretical ecologist at the University of Amsterdam in the Netherlands, said that the Princeton research shows that recently proposed early-warning signals for the desertification of arid ecosystems can be too simple, and possibly result in projections of future climate change that do not account for the complexity of nature. Huisman is familiar with the study, but was not involved in it.