1. Using a Network of Flux Towers to Investigate the Effects of Wetland Restoration on Greenhouse Gas Fluxes Dennis Baldocchi, Jaclyn Hatala, Joe Verfaillie, Sara Knox, Frank Anderson Department of Environmental Science, Policy and Management University of California, Berkeley AGU, 2012

2. Delta Peatland is Subsiding! Landscape is Vulnerable to Flooding by Levee Failure; Its Collapse would Shut-Down California’s Water Conveyance System

3. The Delta is a Vulnerable Ecosystem via Severe Land Subsidence

4. Wetlands in California Provide Huge Potential to Sequester Carbon Long Growing Season & Ample Sunlight Promotes Photosynthesis Flooding Retards Respiration At What Cost? Annual Methane Emission Scales with Net Primary Productivity of Wetlands, Natural and Managed

5. New Plans to Reverse Subsidence with Carbon Farming: Restored Tule Wetlands and Rice on Twitchell and Sherman Islands What are the: Cost/Benefits?; Unintended Consequences?

6. Over-Arching Research Questions How Does Management for Carbon Sequestration and Ecological Restoration affect Methane and Water Loss? – How Large are Carbon Dioxide and Methane Fluxes from Drained & Managed Peatlands (Rice, Corn, Pasture) vs Restored Wetlands on daily, seasonal, annual time scales? – How do Greenhouse Gas Fluxes Respond with Environmental Drivers (Light, Temperature, Oxygen, recent Photosynthesis, Water Table, Fraction of Water/Vegetation)?

7. Delta Field Sites DDB Childhood Home DDB Birth Place

8. Five Contrasting Study Sites Drained Peatland Pasture, BAU Seasonally-Flooded, Rice, Agricultural Option Newly Restored, Wetland 15 Year Old, Restored Wetland Corn, BAU

9. Mean Diurnal Pattern of CO 2 Exchange, Summer 2012 Drainage (corn) & Disturbance by Restoration Promote Dark Respiration Flooding of Rice and the Older Wetland Suppresses Dark Respiration Photosynthesis of C 4 Corn out paces C 3 Photosynthesis of Rice and Wetlands Ranking of Carbon Sequestration Potential, peak summertime: Wetland > Rice > Corn

10. Carbon Sink Strength of Wetland Increases with Time since Restoration C Fluxes Depend on Percent of Open Water in Fetch

11. Wetland Restoration Project, Mayberry Slough

12. Restored Wetland Experiences Weekly Oscillations in Nocturnal Respiration, unlike Other Ecosystems A Challenge for Gap Filling and Modeling if the Excursions represent C Losses non-Local in Time or Due to Change in Wind Direction and Fetch

13. Seasonal Variation in CO 2 Exchange of Rice and Newly Restored Wetland Rice has a Shorter Effective C Sink Period than an Established Wetland Management of Rice can Cause Pulses of Carbon Seed Harvest Switches a C Sink to a Source But, C Fluxes of a Restored Wetland Will Depend on Wind Direction and Fetch

14. Older Wetlands are Profligate Methane Sources! Methane Production from Rice on Peat Soils < than Rice on Clays

15. Rice, on peat, is a Smaller Methane Source than, Non-Tidal, Freshwater, Restored Wetlands

16. Low O 2 in Water Promotes High Methane Fluxes Daily Averages

17. Newly Restored + Older Wetland + Rice Shallow Water (< 10 cm) under Rice is Warmer, More Convective and more Oxygenated, Inhibiting Methane Loss compared to non-Tidal, Older Wetland with Deeper and Colder Water (~ 35 cm)

18. Conclusions Restored Wetlands can be Effective Carbon Sinks – Only, Several Years after Establishment – But, they can produce Huge Amounts of Methane Rice and Corn have Large Photosynthetic Potential, and Flooding Inhibits Soil Respiration, compared to Corn – But, Their Effective Growing Season is Short – Carbon is Exported as Seed, Switching a C Sink to a Source – On Annual Basis, Agroecosystems are Carbon Sources that Mine Soil C