Washington: The large dirt mounds of termites are crucial to stopping the spread of deserts into semi-arid ecosystems and agricultural lands, a new study has found.
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 note 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.
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," said Tarnita.
The mathematical model developed for the latest work determines how termite mounds affect plant growth by applying various tools from physics and mathematical and numerical analysis to understand a biological phenomenon, said first author Juan Bonachela, a former postdoctoral researcher in the group of co-author Simon Levin, Princeton's George M Moffett Professor of Biology.
The research was published in the journal Science.