Leaf cutter ants: a possible missing source of biogenic halocarbons
M. I. Mead A , M. A. H. Khan A C , G. Nickless A , B. R. Greally A , D. Tainton B , T. Pitman B and D. E. Shallcross AA School of Chemistry, University of Bristol, Bristol, BS8 1TS, UK.
B Wildwalk, At-Bristol, Anchor Road, Harbourside, Bristol, BS1 5DB, UK.
C Corresponding author. Email: anwar.khan@bristol.ac.uk
Environmental Chemistry 5(1) 5-10 https://doi.org/10.1071/EN07068
Submitted: 21 September 2007 Accepted: 24 January 2008 Published: 22 February 2008
Environmental context. With large reductions in anthropogenic emissions of many ozone-depleting gases in response to the Montreal Protocol, gases with biogenic sources have become relatively more important in recent years. The global budgets of the biogenic halocarbons are unbalanced with known sinks outweighing sources, suggesting that additional natural sources are required to balance the budgets. In the present study, an investigation has been carried out to determine the importance of leaf cutter ants as a missing source of the biogenic halocarbons, which will reduce the discrepancy of the global budget of the halocarbons.
Abstract. Leaf cutter ant colonies are shown to be a potentially significant new source of biogenic halocarbons. Fungus cultivated by these ant species may emit CH3Br, CH3I, CH3Cl, CH2Cl2 and CHCl3 in significant quantities, contributing to their respective global atmospheric budgets. The study suggests that the mixing ratios of CH3Br, CH3I, CH3Cl, CH2Cl2 and CHCl3 in the ant colony under test were significantly higher than background levels, by on average a factor of 1.5–5.0. Sampling was carried out during three stages of ant colony development (new, moderately active and highly active) and it was found that levels of these halocarbons were elevated during the active phases of the ant colony life cycle. A very rough estimate of the possible emission of CH3Br, CH3I, CH3Cl, CH2Cl2 and CHCl3 from ant colonies globally are 0.50, 0.02, 0.80, 0.15 and 0.22 Gg year–1.
Additional keywords: Adsorption Desorption System (ADS), Automated Thermal Desorber (ATD), Bristol wild walk, gas chromatography (GC), mass spectrometry (MS).
Acknowledgements
MIM would like to thank NERC for a studentship, MAHK was supported by a Dorothy Hodgkin Fellowship and the authors would also like to thank EUROCHLOR under whose auspices various elements of the present work were carried out. The authors would also like to thank the staff at Explore@Bristol for their help and support throughout the present work.
[1]
S. C. Wofsy ,
M. B. McElory ,
Y. L. Yung ,
The chemistry of atmospheric bromine.
Geophys. Res. Lett. 1975
, 2, 215.
| Crossref |
[Verified June 2006].
[34]
[35]
P. G. Simmonds ,
S. O’Doherty ,
G. Nickless ,
G. A. Sturrock ,
R. Swaby ,
A. Knight ,
G. Ricketts ,
G. Woffendin ,
R. Smith ,
Automated gas-chromatograph/mass-spectrometer for routine atmospheric field measurements of the CFC replacement compounds, the hydrofluorocarbons and hydrochlorofluorocarbons.
Anal. Chem. 1995
, 67, 717.
| Crossref | GoogleScholarGoogle Scholar |
[36]
R. G. Prinn ,
R. F. Weiss ,
P. J. Fraser ,
P. G. Simmonds ,
D. M. Cunnold ,
F. N. Alyea ,
S. O’Doherty ,
P. Salameh ,
B. R. Miller ,
J. Huang ,
R. H. J. Wang ,
D. E. Hartley ,
C. Harth ,
L. P. Steele ,
G. Sturrock ,
P. M. Midgely ,
A. McCulloch ,
A history of chemically and radiatively important gases in air deduced from ALE/GAGE/AGAGE.
J. Geophys. Res. 2000
, 105, 17751.
| Crossref | GoogleScholarGoogle Scholar |
[37]
S. A. Montzka ,
J. H. Butler ,
B. D. Hall ,
D. J. Mondeel ,
J. W. Elkins ,
A decline in tropospheric organic bromine.
Geophys. Res. Lett. 2003
, 30, 1826.
| Crossref | GoogleScholarGoogle Scholar |
