To provide estimates of biosphere/atmosphere exchange fluxes on different scales of time and space with the required accuracy to support future European environmental policy in the areas of eutrophication, acidification, oxidant formation and radiative properties of the atmosphere. In order to attain this aim it will be necessary to provide mechanistic research into land/freshwater atmosphere exchange of the gases and aerosols necessary to develop and test deposition and emission models of key gases and aerosols.
Highlights of the scientific results Several field campaigns have been organised within BIATEX, the largest EUROTRAC subproject involving 41 groups from 15 countries. • Joint measurements of the fluxes of nitrogen, sulphur and hydrocarbon compounds have been made over various types of vegetation. • The joint field campaigns and the individual experiments have led to a much better understanding of the mechanisms underlying the surface exchange of trace substances. These campaigns and experiments • have also established a sound basis for the quality of deposition and biogenic emission measurements. The results are being evaluated in order to produce maps of the biogenic emission Of S02, oxidised and reduced nitrogen and for the emission of volatile organic compounds (VOCs) in Europe.