title: CO2 efflux from subterranean nests of ant communities in a seasonal tropical forest, Thailand.
abstract: Many ant species construct subterranean nests. The presence of their nests may explain soil respiration "hot spots", an important factor in the high CO2 efflux from tropical forests. However, no studies have directly measured CO2 efflux from ant nests. We established 61 experimental plots containing 13 subterranean ant species to evaluate the CO2 efflux from subterranean ant nests in a tropical seasonal forest, Thailand. We examined differences in nest CO2 efflux among ant species. We determined the effects of environmental factors on nest CO2 efflux and calculated an index of nest structure. The mean CO2 efflux from nests was significantly higher than those from the surrounding soil in the wet and dry seasons. The CO2 efflux was species-specific, showing significant differences among the 13 ant species. The soil moisture content significantly affected nest CO2 efflux, but there was no clear relationship between nest CO2 efflux and nest soil temperature. The diameter of the nest entrance hole affected CO2 efflux. However, there was no significant difference in CO2 efflux rates between single-hole and multiple-hole nests. Our results suggest that in a tropical forest ecosystem the increase in CO2 efflux from subterranean ant nests is caused by species-specific activity of ants, the nest soil environment, and nest structure.
authors.affiliation: Department of Forest Biology, Faculty of Forestry, Kasetsart University Bangkok, 10900, Thailand ; Center for Advanced Studies in Tropical Natural Resources, NRU-KU, Kasetsart University Bangkok, 10900, Thailand.
authors.forename: Sasitorn
authors.initials: S
authors.lastname: Hasin
authors.affiliation: School of Human Science and Environment, University of Hyogo Himeji, Hyogo, 670-0092, Japan.
authors.forename: Mizue
authors.initials: M
authors.lastname: Ohashi
authors.affiliation: Graduate School of Fisheries Science and Environmental Studies, Nagasaki University Nagasaki, 852-8521, Japan.
authors.forename: Akinori
authors.initials: A
authors.lastname: Yamada
authors.affiliation: Division of Phylogenetics, Museum of Nature and Human Activities, University of Hyogo Sanda, 669-1546, Japan.
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Hashimoto
authors.affiliation: Department of Forest Biology, Faculty of Forestry, Kasetsart University Bangkok, 10900, Thailand ; Center for Advanced Studies in Tropical Natural Resources, NRU-KU, Kasetsart University Bangkok, 10900, Thailand.
authors.forename: Wattanachai
authors.initials: W
authors.lastname: Tasen
authors.affiliation: School of Forestry and Resource Conservation, National Taiwan University Taipei, 106-17, Taiwan.
authors.forename: Tomonori
authors.initials: T
authors.lastname: Kume
authors.affiliation: Department of Earth and Environmental Sciences, Faculty of Science, Kagoshima University Kagoshima, 890-0065, Japan.
authors.forename: Seiki
authors.initials: S
authors.lastname: Yamane
keywords: ant nest; carbon dioxide; environmental factor; ground-dwelling ant; tropical forest