Biogenic fluxes of halomethanes from Irish peatland ecosystems

Irish peatland ecosystems have been shown to be important sources of low molecular weight halocarbons. Emission of CH3Br, CH3Cl, CH3I and CHCl3 was recorded from all peatland sites monitored, with minor flux of other halocarbons at certain sites. Fluxes were found to be highly linked to incident light, with strong diurnal cycles recorded at all open peatland sites. Estimates of halomethane emissions, particularly from coastal peatland and conifer plantation forest floor sites, suggests that these ecosystems may make a significant contribution to the global budgets of several important halocarbons. Global annual fluxes of 4.7 (0.1–151.9), 0.9 (0.1–3.3), 5.5 (0.9–43.4), and 1.4 (0.1–12.8) Gg yr−1 for CHCl3, CH3Br, CH3Cl, and CH3I, respectively, were determined for peatland ecosystems.