1. Group Matyssek Introduction to the Kranzberg site,
Hypotheses and Methods,
Interactions and Timetable
Ecophysiology of Plants
Working Team: Markus Löw (PhD Student), Häberle and Matyssek

2. Kranzberg site

3. Experimental Design 10 adult beech trees 1x O3 (ambient ) 2x O3 Sun
(control)
2x O3
(<150 ppb)
Sun
branches
Shade
branches

4. some facts on Kranzberg Forest
beech/spruce mixed stand
age: y. height: 25 m
precipitation: mm
mean temp.: °C
ozone conc.: daily mean: 40 ppb max. 100 ppb

5. Scaling within CASIROZ
Tree
Stem increment
Stem respiration
Xylem Sap Flow
My work:
Branch
Growth pattern
Gas exchange of twigs
Modeling
Leaf
Chlorophyll fluorescence
Photosynthetic performance
Stomatal conductance and transpiration
Seasonal phenology
Root
patterns
species
Cell
metabolism
antioxidants
Gene expression

6. Main Hypotheses of Group Matyssek
whole-tree response patterns to chronic O3 stress
relates to the O3 uptake rater than AOT concept
Gas exchange  conductivities  validation
Uptake (flux) vs. AOT concept
Micro-deposition samplers (Fabian)
Carbon sink (C gain, Biomass production, Sugars [Rennenberg, Oßwald])
Xylem sap flow (whole-tree C & N cycling (Rennenberg)
Isotope ratios 13C/12C, WUE, 18O/16O (Rennenberg), PEPC / RUBISCO (Oßwald)
Porometry and continuous gas exchange measurements
structural & functional branch assessments: first flush, lammas shoot, phenology  C sink

7. Main Hypotheses II
O3 exposure in shade crowns cannot be neglected with respect to whole-tree sensitivity
O3 exposure during dusk and at night is significant. Therefore the risk of O3 injury is as high as under day-conditions (stomata closed and no light dependent supply of antioxidants)
Antioxidant status and damage amplifying reactions determine the degree of symptom development
Methods: Night time measurements in cooperation with antioxidant-measurements (Tausz)

8. Main Hypotheses III
chronic Ozone impact constrains carbon sink strength in adult trees to an extent which is relevant in relation to expected stimulation under increasing CO2 conditions
Assessments: structural & functional branch assessments, stem increment (Dendrometer), respiration, senescence

9. Main Hypotheses IV
Response mechanisms to ozone in adult trees are not consistent with findings in young trees
Comparison within CASIROZ between adult and young trees
Comparison to published data

10. Interactions Examples of immediate cooperations:
Rennenberg (Isotopes, C & N cycling)
Wieser (Gas exchange young trees, branch autarchy?)
Oßwald (RUBISCO, PEPC, sugars, starch)
Tausz (antioxidants, night assessments)
Hanke (leaves: cytokinins, ABA)
Ceulemans (modeling)
Fabian (climatic data, O3-regimes)

11. Timetable