University of Miami tropical biologist Amy Zanne led an international research study to investigate the discovery and decay of termites and microbial wood.
Most people think of termites as a nuisance that consumes wood in homes and businesses. But these termites make up less than 4 percent of all termite species worldwide.
Termites are vital in natural ecosystems — especially in the tropics — because they help recycle dead wood from trees. Without such blighters, the world would be littered with dead plants and animals.
But these energetic, wood-eating insects could soon be moving toward the North and South Poles as global temperatures warm due to climate change, new research shows.
In an international study led by University of Miami biology professor Amy Zanne, researchers have found that termites play a key role in breaking down wood and contributing to the Earth’s carbon cycle. They also learned that termites are very sensitive to temperature and precipitation. So as temperatures get warmer, the insect’s role in wood decomposition will likely expand beyond the tropics.
Amy Zanne is the Aresty Chair in Tropical Ecology in the Department of Biology at the College of Arts and Sciences. Photo: Evan Garcia/University of Miami
“With rising temperatures, the impact of termites on the planet could be enormous,” said Zanne, the Aresty Chair in Tropical Ecology in the Department of Biology at the College of Arts and Sciences.
For the study, published in the journal Science, Zanne and more than 100 collaborators examined locations around the world where bacteria and fungi (microbes) and termites eat dead wood. They also studied how temperature and precipitation might affect wood discovery and decay using the same experimental setup at more than 130 sites in a variety of habitats on six continents. Their findings suggest that areas of high termite activity should increase as the earth becomes warmer and drier.
“Termites have had their greatest impacts in places like tropical savannas and seasonal forests and subtropical deserts,” Zanne noted. “These systems are often underestimated in terms of their contribution to the global carbon budget.”
Amy Austin, an associate professor of ecology at the Universidad de Buenos Aires and a collaborator with Zanne, said the global study helped scientists gain broader insight into wood decay.
“Including dry, hot bioregions, particularly in the Southern Hemisphere where termites are often abundant and active, provided new insights into their role in carbon turnover,” Austin said. “As ecologists, we may need to broaden our view of forest ecosystems beyond a closed-canopy forest and recognize that charcoal stores in drier ecosystems are an important part of the global carbon cycle.”
Asian underground termite (Coptotermes gestroi) soldier in cardboard nest. C. gestroi is a wood-eating termite. Photo courtesy of Thomas Chouvenc
Although both microbes and termites decompose dead wood, there are important differences between them. While microbes need water to grow and consume wood, termites can function at relatively low humidity levels. In fact, termites can look for their next meal even if it’s dry and bring what they want back to their mounds or even move their colony into the wood they consume.
“Microbes are important worldwide when it comes to wood rot, but we have largely overlooked the role of termites in this process. That means we don’t consider the massive impact these insects could have on the future carbon cycle and interactions with climate change,” Zanne explained.
Like little cows, termites release carbon from wood in the form of methane and carbon dioxide, two of the most important greenhouse gases. Therefore, according to Zanne, termites could contribute increasingly to greenhouse gas emissions with climate change.
“I am fascinated by how microbial and termite wood decay affects the release of carbon into the environment,” said the researcher, who has been studying feedbacks from wood-based carbon release for more than a decade.
Zanne began her research on termites in 2008 and joined other wood decay experts when she took part in a research group in Sydney, Australia. This led to a major research project in Queensland, Australia, funded by the National Science Foundation and the Natural Environment Research Council, which even included collaborating with artist Donna Davis to depict termites, microbes and decaying wood.
She expanded the study globally through social media and word of mouth, including researchers across career levels and locations, all conducting the same experiment with locally sourced materials.
André M. D’Angioli, a Brazilian biologist, collaborated on the project as part of his PhD at the Universidade Estadual de Campinas.
“Participating in the global timber project was a big step for my research,” he said. “It was fascinating to see how the regional data I collected in Brazil correlated with the global patterns found in this paper.”
Zanne said the opportunity to lead a global research venture is extremely rewarding.
“This is one of the most incredible projects I’ve ever worked on,” she said. “It was a truly international collaboration. Our ability to better understand wood decay and parts of the carbon cycle on a global scale is now better because of this research.”
The study, “Termite Temperature Sensitivity Affects Global Wood Decay Rates,” was published in the September 23 issue of Science and is also available online.
