Greenhouse Gas (CO2, CH4, H2O) Fluxes From Drained And Flooded Agricultural Peatlands In The Sacramento-San Joaquin Delta

  • Sites: US-Snd, US-Twt
  • Publication Type: JOUR
  • Authors: Hatala, J. A.; Detto, M.; Sonnentag, O.; Deverel, S. J.; Verfaillie, J.; Baldocchi, D. D.

  • The Sacramento-San Joaquin Delta in California was drained and converted to agriculture more than a century ago, and since then has experienced extreme rates of soil subsidence from peat oxidation. To reverse subsidence and capture carbon there is increasing interest in converting drained agricultural land-use types to flooded conditions. Rice agriculture is proposed as a flooded land-use type with COsequestration potential for this region. We conducted two years of simultaneous eddy covariance measurements at a conventional drained and grazed degraded peatland and a newly converted rice paddy to evaluate the impact of drained to flooded land-use change on CO2, CH4, and evaporation fluxes.

    We found that the grazed degraded peatland emitted 175–299 g-C m−2 yr−1 as CO2 and 3.3 g-C m−2 yr−1 as CH4, while the rice paddy sequestered 84–283 g-C m−2 yr−1 of CO2from the atmosphere and released 2.5–6.6 g-C m−2 yr−1 as CH4. The rice paddy evaporated 45–95% more water than the grazed degraded peatland. Annual photosynthesis was similar between sites, but flooding at the rice paddy inhibited ecosystem respiration, making it a net CO2 sink. The rice paddy had reduced rates of soil subsidence due to oxidation compared with the drained peatland, but did not completely reverse subsidence.

  • Journal: Agriculture, Ecosystems & Environment
  • Funding Agency: —
  • Citation Information:
  • Volume: 150
  • No:
  • Pages: 1-18
  • Publication Year: 2012/03
  • DOI: 10.1016/j.agee.2012.01.009