Dirt mounds made by termites could prevent spread of deserts

http://www.eurekalert.org/pub_releases/2015-02/nsf-dmm020515.php

Public Release: 5-Feb-2015 Dirt mounds made by termites in Africa, South America, Asia could prevent spread of deserts
Termites create oases of moisture, plant life
National Science Foundation

Termites might not top the list of humanity's favorite insects, but new research suggests that their large dirt mounds are crucial to stopping deserts from spreading into semi-arid ecosystems.

The results indicate that termite mounds could make these areas more resilient to climate change.

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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 vulnerable to desertification.

Researchers report in this week's issue of the journal Science that termites slow the spread of deserts into drylands by providing a moist refuge for vegetation on and around their mounds.

Drylands with termite mounds can survive on significantly less rain than those without termite mounds.

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Corresponding author Corina Tarnita, a Princeton University ecologist and evolutionary biologist, said that termite mounds also preserve seeds and plant life, which helps surrounding areas rebound faster once rainfall resumes.

"Because termites allow water to penetrate the soil better, plants grow on or near the mounds as if there were more rain," said Tarnita. "The vegetation on and around termite mounds persists longer and declines slower.

"Even when you get to 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."

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Robert Pringle, an ecologist and evolutionary biologist at Princeton and co-author of the paper, said that the unexpected function of termites in savannas and grasslands suggests that ants, prairie dogs, gophers and other mound-building creatures could also have important roles in ecosystem health.

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