1. The Carbon Sink Strength of Beech in a Changing Environment: Experimental Risk Assessment of Mitigation by Chronic Ozone Impact Participant 7, PD. Dr. G. Wieser, Dipl.-Bio. Ch. Then, Ing. T. Gigele

2. Validation of the ecological significance of former O 3 studies l l Climatised twig chambers enhanced O 3 in control trees and cuvettes with ambient air in O 3 fumigated trees ►clarify profit from defence capacity of neighbouring crown parts l l 3-year-old container grown seedlings in fumitared and non fumigated areas of the sun- and shade exposed canopy ►improve the ability for upscaling from seedling studies to adult trees Aims

3. Calculation of O 3 uptake l l Climatised twig chambers continuous measurements of microclimate, O 3 leaf gas exchange l l Seedlings repeated diurnal courses of stomatal conductance (portable gas exchange system; LCA3, ADC) and modeling (Emberson model) Methods

4. Estimation of O 3 effects l l Photosynthetic capacity l l Carboxylation efficiency l l Night time respiration Thermoelectrically climate-controlled Minicuvette System (Walz): 20 °leaf temperature 9.2 Pa kPa -1 VP DLA 350 µmol mol -1 CO 2 light saturation (artificial light souce) l l Quantum yield l l Chlorophyll fluorescence Mini-Pam (Walz) l l Growth l l SLA Methods

5. Measurement Schedule MonthMeasurement or activity twig chambers Measurement or actvity container growns sedlings MayContainer transfer to canopy Growth measurements Leaf morphology (SLA) Diurnal Physiology Estimation of O 3 effects JuneGrowth measurements Leaf morphology (SLA) Diurnal Physiology JulySystem instalationGrowth measurements Leaf morphology (SLA) Diurnal Physiology Estimation of O 3 effects Aug.System testingGrowth measurements Leaf morphology (SLA) Diurnal Physiology Sept.System testingGrowth measurements Leaf morphology (SLA) Diurnal Physiology Oct. System removal for passing the winter Growth measurements Leaf morphology (SLA) Diurnal Physiology Estimation of O 3 effects Container removal for passing the winter Sample harvest LMR, root/shoot ratio Growig season 2003

6. MonthMeasurement or activity twig chambers Measurement or actvity container growns sedlings MaySystem instalation Start of fumigation Growth measurements Leaf morphology (SLA) Estimation of O 3 effects Container transfer to canopy Growth measurements Leaf morphology (SLA) Diurnal Physiology Estimation of O 3 effects JuneGrowth measurements Leaf morphology (SLA) Diurnal Physiology JulyGrowth measurements Leaf morphology (SLA) Estimation of O 3 effects Growth measurements Leaf morphology (SLA) Diurnal Physiology Estimation of O 3 effects Aug.Growth measurements Leaf morphology (SLA) Diurnal Physiology Sept.Growth measurements Leaf morphology (SLA) Diurnal Physiology Oct.Growth measurements Leaf morphology (SLA) Estimation of O 3 effects End of fumigation and System removal Growth measurements Leaf morphology (SLA) Diurnal Physiology Estimation of O 3 effects Containe removal and Final harvest LMR, root/shoot ratio Growig season 2004 Measurement Schedule

7. Co-operation and data exchange with partner groups l l Participant 1 (Matyssek in WP1) Ecophysiological comparison of gas exchange data obtained from twig chambers and seedlings with canopy data from the Free Air Canopy Ozone Exposure (FACOE) system l l Participant 2 (Oßwald in WP 1 and 2) l l Participant 4 (Renneberg in WP 2) l l Participant 8 (Tausz in WP 2) providing O 3 uptake data for relating molcular and biochemical parameters to the effective O 3 dose taken up by the leaves with respect to the sampling protocols of partner 2, 4, and 8 Interface

8. Overall contribution Determine age and size related differences in: l lO 3 influx l lLeaf morphology l lGas exchange behaviour Linking O 3 avoidance (uptake) and tolerance (detoxification) to a conceptual framework