Yearly follow-up of methane turbulent exchange over an intensively grazed pasture in Belgium.

Methane emissions account for 8 % of the EU-15 GHG emissions and livestock generates 40 % of these emissions (European Commission, 2009). These fluxes are mainly measured in metabolic chambers with the drawback of bringing the cattle in an unfamiliar environment. Recent technological advances in spectroscopy now permit methane flux measurement using eddy covariance. This micrometeorological method has numerous strengths. It can measure fluxes in situ, continuously and across broad areas. This provides information about grassland and cattle emission behaviour throughout the year and across a broad range of climatic conditions. We present here a one year monitoring of methane exchange between an intensively grazed grassland and the atmosphere obtained using the eddycovariance method.