1. The effect of ozone on VOC- emission from peatland Åsmund Rinnan Quality & Technology Department of Food Science Faculty of Life Sciences University of Copenhagen Denmark

3. People involved Riikka Rinnan – sampling, measurements, background Toini Holopainen – plant responses to O 3 Jarmo K. Holopainen – plant VOCs Pertti Pasanen – indoor air VOCs Rinnan R., Rinnan Å., Holopainen T., Holopainen J.K. & Pasanen P. (2005) Emission of volatile organic compounds (VOC) from boreal peatland microcosms –effects of ozone exposure. Atmospheric Environment 39: 921-930.

4. Questions to be answered Are specific plant species related to emission of certain VOCs? What is the general effect of ozone on VOC emissions from peatland?

5. Peatland microcosms

6. Depth 40 cm ø 11 cm Water table at -2 cm Eriophorum vaginatum Eriophorum vaginatum Andromeda polifolia Andromeda polifolia Sphagnum mosses Vaccinium oxycoccus

7. Ozone exposure Computer-controlled growth chambers 0, 50, 100 & 150 ppb ozone 5 weeks VOC collection from 4 microcosms/treatment = 16 in total VOC divided into 9 sub- groups

8. Ozone treatment Species abundance 0 ppb50 ppb100 ppb150 ppb Sample 1-41000 Sample 5-80100 Sample 9-120010 Sample 13-160001 Emission data Plant species vs Emission of VOCs

9. Ozone treatment Species abundance Emission data PLS B = [ B Species abundance B Ozone ] Plant species vs Emission of VOCs

10. Mean regression coefficientsStandard deviation of regression coefficients Regression coefficients from Jack-Knifing (Leave-One-Out)

11. Mean regression coefficients Standard deviation of regression coefficients Plant species vs Emission of VOCs Regression coefficients from Jack-Knifing (Leave-One-Out) OzonePlant species

12. Regression coefficient Vaccinium Andromeda Eriophorum Sphagnum Plant species vs Emission of VOCs

13. Regression coefficient

14. Sphagnum Andromeda 0 ppb 50 ppb 100 ppb 150 ppb Shows 2D, in reality 6D Virtual sample Effect of ozone on emission of VOCs

15. 100 ppb Control of virtual sample

16. InformationNoise Species abundance Species abundance = Information + Noise Effect of ozone on VOC emission

17. Information Emission data MLR Effect of ozone on VOC emission

18. Predicted VOC emission Plant PC 1 Real sample Virtual sample Predicting VOC-emission

19. Predicted VOC emission Measured VOC emission Prediction error Real sample Estimating the uncertainty of prediction

20. Species abundance NoiseInformation Emission data MLR Predicted VOC emission Plant PC Predicted VOC emission Measured VOC emission Prediction error 1 4 3 2 The whole prediction process

21. Effect of ozone on emission

23. Conclusion PLS with dummy variables helped us find the specific plants contribution to the VOC- emission Creating a virtual sample made it possible to evaluate the effect the ozone-level had on the VOC-emission