Contributions of Reticulitermes flavipes (Isoptera: Rhinotermitidae) to greenhouse gases, CO2 and CH4, on the Oklahoma Tallgrass Prairie Preserve

Evidence indicates that carbon dioxide and methane are important greenhouse gases that may influence global temperatures.  Contributions of these gases by mound-building termites have been well studied.  However, CO₂ and CH₄ contributions by temperate zone, non-mound-building subterranean termites is poorly defined.  This field experiment was conducted to quantify the gas output from foraging subterranean termites, Reticulitermes flavipes (Kollar), on the Oklahoma Tallgrass Prairie Preserve (TGPP).  During May through December 2014, gas samples were collected monthly from flux chambers at 0-, 30-, and 60-minute intervals and analyzed via gas chromatography.  Termites emitted the greatest volumes of CO₂ during May (11.5 mg CO₂ L^-1 h^-1) and June (5.1 mg CO₂ L^-1 h^-1), then emissions steadily declined from July through December.  CH₄ emitted was highest in May (3.2 µg L^-1 h^-1), then decreased and stabilized in June, July, and August (2.1, 2.0, and 2.1 µg L^-1 h^-1, respectively).  During cooler October and December seasonal temperatures, significantly lower CO₂ and CH₄ emissions occurred.  Environmental conditions during May and June are more conducive to termite foraging.  Due to drier soils and extreme heat, termite foraging activity began to decline during July and August. The data suggest a direct correlation between the number of termites present at the time of sampling and CO₂ production, but this was not observed for CH₄ emissions.  This research shows that R. flavipes contributes significant amounts of CO₂ and CH₄ to the local atmosphere.