image: These are termite mounds in a North Australian tropical savanna landscape during the wet season. Termite colonies can be significant sources of methane to the atmosphere, but their mounds act as efficient biofilters to intercept substantial amounts of greenhouse gas before emission. view more
Credit: Image courtesy of Philipp A. Nauer.
A study explores turnover of the greenhouse gas methane in termite mounds, which act as biofilters. Termite breakdown of plant material is a component of carbon cycling in tropical ecosystems. Such decomposition also produces globally significant amounts of the greenhouse gas methane, but little is known about methane turnover within the large and intricate structures of termite mounds. Philipp Nauer and colleagues quantified methane turnover in 29 mounds of three tropical termite species in northwest Australia. The authors used three independent methods to measure methane production, oxidation, and transport in the mounds in situ. Comparing methane injected into the mounds against a nonreactive tracer gas revealed that the mounds oxidize methane. Further measurements confirmed that the mounds emit methane into the atmosphere, but methanotrophic bacteria, living in either the mounds or the soil underneath, intercept, on average, half of the methane produced by termites. The authors note that methane turnover data can be used to determine termite biomass with minimal disturbance to the mounds. Further research is needed to determine temporal variations in methane turnover and oxidation in nests made of materials other than soil, but the findings suggest that in situ measurements can lead to precise estimates of termites' contribution to the global methane emissions budget, according to the authors.
Article #18-09790: "Termite mounds mitigate half of termite methane emissions," by Philipp A. Nauer, Lindsay B. Hutley, and Stefan K. Arndt.
MEDIA CONTACT: Philipp A. Nauer, The University of Melbourne, Richmond, AUSTRALIA; e-mail: pnauer@unimelb.edu.au; Stefan K. Arndt, The University of Melbourne, Richmond, AUSTRALIA; e-mail: sarndt@unimelb.edu.au
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