Most people think termites are a nuisance that consumes wood in homes and businesses. In reality, these termites represent less than four percent of all termite species worldwide. Termites are critical in natural ecosystems—especially in the tropics—because they are key players in wood decomposition. The world would be piled high with dead plants and animals without termites.
Forested ecosystems contain over 675 billion metric tons of biomass; a significant fraction of that biomass has been immobilized for centuries in wood. According to new research, and in conjunction with current global change trends, where we expect warming shifts to tropical climates in many areas around the planet, the effect termites could have on wood decay is likely to increase as termites are predicted to have access to ecosystems where they are not currently present.
In an international study that collected data in 133 sites spanning 20 countries, assistant professor Paul-Camilo Zalamea and research associate Carolina Sarmiento from the Department of Integrative Biology at the University of South Florida, along with more than 100 collaborators, learned that termites are pivotal when it comes to breaking down wood, contributing to the earth's carbon cycle. Their research also showed that termites are very sensitive to temperature and rainfall – as temperatures heat up, the termite's role in wood decay will likely expand beyond the tropics.
"We found that termite discovery and wood consumption were highly sensitive to temperature. This result has tremendous consequences for understanding carbon storage," said Zalamea, also a research associate at the Smithsonian Tropical Research Institute in Panama.
Global wood block decay experiment located in tropical lowland forest in Barro Colorado
Island, Panama.
Photos by Paul-Camilo Zalamea.
For the study, published in the journal Science, lead author Amy Zanne (University of Miami) and collaborators studied wood decomposition using the same experimental design replicated in a variety of habitats across six continents.
"This paper results from a massive collaborative effort. In my research group, we were in charge of running the wood decay experiment deployed on Barro Colorado Island (BCI) in Panama," Zalamea added. "This study is the largest collaboration I have worked on, and it was gratifying to see how the local scale data we collected in Panama was related to the global patterns described in the paper," Sarmiento added.
Barro Colorado Nature Monument, and Gatun Lake, Panama. Photo by Paul-Camilo Zalamea.
Like cows, termites release carbon from the wood as methane and carbon dioxide, which are two of the most important greenhouse gases. Thus, expansions in termite distributions may increasingly contribute to greenhouse gas emissions.
"Before the publication of our paper, little was known about the climate sensitivity of termites in wood decay; now we know that termites are highly sensitive to temperature, considerably more than microbes, widely known in the literature as key players in wood decay," added Zalamea. "This finding is extremely relevant, because it shows how termites have been overlooked in the past, and it improves our ability to better understand the carbon cycle globally," Sarmiento added.
Adapted from University of Miami press release by Paul-Camilo Zalamea, Ph.D., Assistant Professor, Department of Integrative Biology and Carolina Sarmiento, Research Assistant, Department of Integrative Biology