Data from: Leaf-cutter ants engineer large nitrous oxide hot spots in tropical forests

Though tropical forest ecosystems are among the largest natural sources of
the potent greenhouse gas nitrous oxide (N2O), the spatial distribution of
emissions across landscapes is often poorly resolved. Leaf-cutter ants
(LCA, Atta and Acromyrmex, Myrmicinae) are dominant herbivores throughout
Central and South America and influence multiple aspects of forest
structure and function. In particular, their foraging creates spatial
heterogeneity by concentrating large quantities of organic matter
(including nitrogen, N) from the surrounding canopy into their colonies,
and ultimately, into colony refuse dumps. Here, we demonstrate that refuse
piles created by LCA species Atta colombica in tropical rainforests of
Costa Rica provide ideal conditions for extremely high rates of N2O
production (high microbial biomass, potential denitrification enzyme
activity, N content, and anoxia), and may represent an unappreciated
source of heterogeneity in tropical forest N2O emissions. Average
instantaneous refuse pile N2O fluxes surpassed background emissions by
more than three orders of magnitude (in some cases exceeding 80,000 μg
N2O-N m-2 h-1) and generating fluxes comparable to or greater than those
produced by engineered systems such as wastewater treatment tanks.
Refuse-concentrating Atta species are ubiquitous in tropical forests,
pastures and production ecosystems, and increase density strongly in
response to disturbance. As such, LCA colonies may represent an
unrecognised greenhouse gas point source throughout the Neotropics.