Above surface processes –

eddy covariance gas exchange

The carbon balance in a wetland

3 restored tidal wetlands

5 restored nontidal wetlands

3 Agricultural/pasture sites

San Francisco Bay-Delta

1 historic tidal wetland

Eddy Covariance

Most agricultural sites are strong sources of GHG

Wetlands can be sinks of GHG but there is high interannual variability

Coastal wetland can be large sources of CH₄

Radiative forcing of wetland restoration

Arias-Ortiz et al. 2021

Atmospheric Carbon Fluxes at Eden Landing and Rush Ranch

• Average annual removal of CO₂= 407.4 g C-CO₂ m^-2 yr^-1 (SD= 47.1)
• Average Annual emission of CH₄ = 0.6 g C-CH₄ m^-2 yr^-1 (SD=0.3)

• Average Annual removal of CO₂= 287.3 g C-CO₂ m^-2 yr^-1 (SD= 94.5)
• Average Annual emission of CH₄ = 0.91 g C-CH₄ m^-2 yr^-1 (SD=0.3)

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Estimating Net Ecosystem Balance

Rush Ranch (US-Srr) and Eden Landing (US-Edn)

Combining soil sediment, lateral and atmospheric carbon fluxes to estimate NECB

Bogard et al. 2020 US-Srr

• Atmospheric removal = -255 g C m^-2 y^-1
• Lateral export = 105 g C m^-2 y^-1

Arias-Ortiz et a. 2021 US-Edn

• Atmospheric removal= 386 g C m^-2 y^-1
• Soil organic carbon = 70 g C m-2 y-1
• Estimated Lateral export= 316 g C m^-2 y^-1

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Long-term measurements

US-Myb Annual budgets: nontidal managed wetland, decreasing CH₄ emissions with time

Matsumura et al. in prep