University of Antwerpen UA Database and stand level modelling Gaby Deckmyn

1. University of Antwerpen UADatabase and stand level modellingGaby Deckmyn Objectives for CASIROZ • Develop and maintain the database • Develop, parameterise, validate and use a model to predict the effect of ozone on European forests

2. University of Antwerpen UADatabase Current situation: • Database developed • First year data from the German groups have been submitted • Other data still missing • Vincent Budts has left, I will take responsibility until we have a new PHD student Please submit data ASAP

3. Stand level modelling, UA Current Situation: * The Mefyque model is running • Validation is underway • The model is ‘ready’ to add the ozone effects

4. Stand level modelling, UA General output • Daily Biomass and volume of all compartments • Daily C and H2O fluxes • Light absorbtion per layer • Daily LAI and LA distribution • Halfhourly photosynthesis, transpiration and respiration (per layer) • Energy budget • Total C budget • Wood development: EW/LW, density, pipe radius

5. Changes made to allow ozone effects: • Stomatal fuctioning simulated using Dewar model (2002) based on soil and leaf water potentials influencing ABA concentration. • On halfhourly basis • This allows exact calculation of the ozone uptake by the tree (and even per leaf area and with difference between sunlit and shaded leaves) • A1lows effects of ozone on stomatal functioning to be included in a functional way, but input from the measurements is needed to decide how.

6. Changes made to allow ozone effects: • Photosynthesis simulated using Farquhar model • On halfhourly basis, per leaf layer, for sunlit and shaded leaves • A1lows effects of ozone on photosynthesis to be included in a functional way, but input from the measurements is needed to decide how.

7. Changes made to allow ozone effects: 3. Soil model • A new soil model has been developed • The model will be validated during the coming months • Main innovation is the inclusion of mychorrisae as a seperate C-pool, in competition with soil bacteria and soil fungi • Degradation of soil C depends on the availability (from T, water, soil structure and composition of the material) but secondly on the activity of the soil organisms competing for the energy and nutrients from degradation. • Trees benefit from the N from mychorrisae, that benefit from tree C

8. Stand level modellingMain developments in the near future: • Improving and validating soil model • Include calculation of ozone flux in the leaves • Include ozone effects on stomatal functioning and photosynthesis • Include ozone effects on the soil (if significant) • Parametrise for the Kranzberg site • Validate for the CASIROZ data

9. What we would like to receive: • New data from project (preferably linked and analysed for environmental effects) and existing data : • Tree height, shape • LAI, SLA • Photosynthesis: A/Ci, chlorophyll • Ozone effects on C allocation • C cost for defense • Stomatal conductance • Transpiration, sapflow • Respiration • Phases: budbreak, leaffall • Climate, including ozone

10. Stand level modellingTime frame • Soil model validated and improved December 2004 • Master thesis including the full ozone model by may 2005 • Parametrisation and validation for the Kranzberg site by July 2005 Cooperation for specific validation and publication is welcome!