Relevance of the project objectives

For the assessment of ozone impact on forests, the main discussions, during previous workshops, stress that the flux-based method is better than the concentration-based method. The following recommendations were made:

  • Further field-based validation of ozone flux-effect relationships and critical levels for vegetation are required via epidemiological studies (ozone-induced symptoms assessment)
  • Validation of DO3SE with eddy covariance flux data would make a valuable contribution.

The ozone flux-based method should be further developed by:

  • Expanding the number of species with flux-effect relationships
  • Further qualifying and quantifying uncertainties
  • Further stimulating the cooperation with ICP Forests
  • Adding flux parameterisations for additional species.

With respect to the above recommendations, the FO3REST project is totally suitable and provides an opportunity to infer an evaluation of the DO3SE model parameterisation through a comparison of observed, with field campaigns, and modelled total O3 deposition and to extend the number of DO3SE model evaluation studies conducted under “Mediterranean style” conditions at 4 locations with different Mediterranean tree species, such as Pinus halepensis, Quercus ilex, Pinus pinea. Furthermore, the modelling and measurements of ozone fluxes will be translated into real-world Mediterranean forest impacts in terms of growth and visible injury. Most experiments to establish biologically relevant plant responses have been performed under controlled conditions not representative of actual field conditions and the results may not provide realistic results for developing standards for protecting vegetation in natural environments. FO3REST is directed toward a specific analysis of ozone symptoms and real damage levels in the field, trying to define more realistic thresholds for vegetation protection against ozone pollution.