CO2 efflux from subterranean nests of ant communities in a seasonal tropical forest, Thailand.

Sasitorn Hasin,Tomonori Kume,Mizue Ohashi,Akinori Yamada,Yoshiaki Hashimoto,Seiki Yamane,Wattanachai Tasen

doi:10.1002/ece3.1255

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.

Highlights

Soil respiration is the total CO2 efflux from the soil surface, a major component of the carbon cycle in an ecosystem (Luo and Zhou 2006)
In tropical seasonal forests, total soil CO2 efflux clearly fluctuates with changes in soil moisture because there are distinct dry and wet seasons characterized by large differences in rainfall (Kume et al 2012)
Ecology and Evolution published by John Wiley & Sons Ltd

Summary

Introduction

Soil respiration is the total CO2 efflux from the soil surface, a major component of the carbon cycle in an ecosystem (Luo and Zhou 2006). Accurate estimations of total soil CO2 efflux are important to calculate the net carbon exchange between the atmosphere and terrestrial ecosystems (Raich and Potter 1995). The total soil CO2 efflux fluctuates with changes in temperature and moisture (e.g., Xu and Qi 2001). In temperate and boreal ecosystems, temperature affects total soil CO2 efflux more strongly than does moisture, whereas in tropical ecosystems, the opposite situation can occur (Malhi et al 1999). In tropical seasonal forests, total soil CO2 efflux clearly fluctuates with changes in soil moisture because there are distinct dry and wet seasons characterized by large differences in rainfall (Kume et al 2012).

Objectives

Methods

Results

Discussion

Conclusion