1. Hojeong Kang Yonsei University Korea 2009 TERRECO Effects of Water Level Drawdown & Elevated Temperature on Peatland Microbes

2. Contents Backgrounds 1 1 Water Level Drawdown 2 2 Temperature rise 3 3 Summary 4 4

3. Backgrounds - Climate Changes & Peatlands

4. Climate changes include Higher temperatureElevated CO 2 Drought & floodingSea level rising

5. Rising temperature (Global) IPCC (2007)

7. Changes in precipitation 1999 vs. 1900 IPCC (2000)

8. Projections of future precipitation 2090-2099 December to February June to August IPCC (2007)

9. Accumulation of un-decomposed organic matter as peat C sink –455 Pg C (cf. 750 Pg C in the atmosphere) –1/3 of SOM Destruction → CO 2, DOC releases –Excavation for energy source –Land use changes –Climate changes Peatlands

10. Classification for peatlands BogFenRiparian Nutrient OligotrophicMesotrophicEutrophic Hydrology Ombrogenous (precipitation) Transition (groundwater flow) Minerogenous (stream or lakes) Soil pH 3.8 ~ 4.44.0 ~ 6.36.0 ~ 6.5 Organic matter 85 ~ 99%20 ~ 90%5 ~ 30% Vegetation Moss (Sphagnum) Grass and Sedge (Carex, Juncus, Festuca) Reed or tree (Phragmites, Cypress, Salix)

11. Play a key role in peatland biogeochemistry – CO 2, CH 4, N 2 O production – Decomposition of OM Culture-based methods account for only 1- 5% Molecular approaches –T-RFLP, DGGE –Realtime Q-PCR –Sequencing (Cloning, pyrosequencing) Microbes

12. To determine effects of –water level drawdown during summer –warming for 3 years on microoganisms in peatland –Microbial community structure –Microbial abundance Objectives

13. Water Level Drawdown

14. Objectives Effects of drought on microbial communities in wetlands

15. Soil cores collected from three types of wetlands (riparian, fen, and bog) in north Wales, UK. Organic content (%) 20406080 3 4 5 6 7 Nitrogen (%) 1 2 3 4 pH Nitrogen Lake (Riparian) Fen Bog Soil pH Source: Mitch and Gosselink, 2000

16. Microcosms Riparian Fen Bog Surface 10cm 20cm 11cm 4 weeks incubation Draining 39% ±1.455% ±1.755% ±1.2

17. Methods Analysis of Microbial communities –Eubacteria (bacterial 16S rRNA genes) –Denitirifiers (nirS genes) –Methanogens (mcrA genes) Real-Time PCR (Abundance) T-RFLP (Diversity, composition)

18. (rdp8.cme.msu.edu/html/t-rflp_jul02.html) T-RFLP (Terminal Restriction Fragment Length Polymorphism)

19. Real Time Q-PCR (Source: Quantabio.com)

20. Drought effect: Abundance (RT-PCR) Microbial community Treatments Gene copy numbers g -1 dry soil (Mean ± SEM) RiparianFenBog Bacteria Control 5.6×10 8 ± 1.9×10 8 7.7×10 9 ± 2.1×10 9 1.7×10 10 ± 3.2×10 9 Drought 2.0×10 8 ± 5.3×10 7 1.1×10 9 ± 2.0×10 8 * 2.3×10 9 ± 2.0×10 8 ** Methanogens Control 1.8×10 7 ± 6.3×10 6 3.3×10 8 ± 2.7×10 8 1.4×10 8 ±2.0×10 7 Drought 7.2×10 6 ± 2.2×10 6 5.8×10 8 ± 5.6×10 8 1.7×10 7 ± 3.4×10 6 *** Denitrifiers Control 1.4×10 7 ± 2.7×10 6 1.9×10 8 ± 1.5×10 7 1.4×10 8 ± 3.0×10 7 Drought 9.7×10 6 ± 1.5×10 6 4.5×10 7 ± 6.9×10 6 *** 2.1×10 7 ± 2.7×10 6 ** Soil Biology & Biochemistry (2008)

21. Drought effects: Composition MRPP test A statistic Difference in proportional abundance BacteriaMethanogensDenitrifiers Bog--- Fen--- Riparian0.04 (p < 0.05)--

22. Drought effects: Diversity Microbial community Treatments Mean ± SEM RiparianFenBog Bacteria Control3.9 ± 0.093.6 ± 0.113.2 ± 0.07 Drought 3.3 ± 0.11*3.7 ± 0.05 3.5 ± 0.13 ( * ) Methanogens Control0.8 ± 0.491.0 ± 0.131.3 ± 0.12 Drought0.9 ± 0.271.0 ± 0.381.3 ± 0.38 Denitrifiers Control1.9 ± 0.391.8 ± 0.381.8 ± 0.22 Drought 2.3 ± 0.18 ( * ) 2.1 ± 0.372.2 ± 0.29

23. BacteriaMethanogensDenitrifiers AbundanceBog Fen- Riparian--- CompositionBog--- Fen--- Riparian-- DiversityBog -- Fen--- Riparian- Drought effects: Summary ↓ ↓ ↓↓ ↓ ↓ ↑ (*) Change

24. Drought Decreased abundance in bog and fen No changes in composition Various responses in diversity Summary

25. Elevated Temperature

26. Control: Ambient temperature Treatment: + 3° C for 3 years Solardomes

27. Warming on peatland (RT-PCR) Kim et al. (unpublished data)

28. Warming effects: MRPP test Treatments A statistics Warming effect Soil Depth EubacteriaMethanogen Surface 0.220 (P<0.01)- Middle 0.190 (P<0.01)- Deep --

29. Eubacteria

30. Methanogen

31. Summary

32. Decrease in abundance in bog and fen No changes in composition Various responses in diversity Water level drawdown Elevated temperature Decrease in methanogen / eubacterial abundance Changes in eubacterial community Decreases in diversity of eubacteria

33. Prof. C. Freeman, Drs. N. Fenner, S-Y. Kim, S-H. Lee NRF & EcoSTAR for financial supports Acknowledgements