Biogenic fluxes of halomethanes from Irish peatland ecosystems

Irish peatland ecosystems have been shown to be important sources of low mo lecular weight halocarbons. Emission of CH3Br, CH3Cl, CH3I and CHCl3, was r ecorded from all peatland sites monitored, with minor flux of other halocar bons at certain sites. Fluxes were found to be highly linked to incident li ght, with strong diurnal cycles recorded at all open peatland sites. Estima tes of halomethane emissions, particularly from coastal peatland and conife r plantation forest floor sites, suggests that these ecosystems may make a significant contribution to the global budgets of several important halocar bons. 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, respecti vely, were determined for peatland ecosystems. (C) 2000 Elsevier Science Lt d. All rights reserved.