The San Joaquin Marsh is one of the final remnants of a wetland, prior to the early 1900s, covered 2100 ha along San Diego Creek. Most of the regional wetlands were drained for agriculture in the early 20th century. Despite regional wetland removal, the San Joaquin remained intact. During the 1950's, vegetation was cleared to promote duck hunting. No further disturbances have occurred since the clearing. The hydroperiod is partly managed by the SJFM VC Reserve and the Irvine Ranch Water District. During the spring months, water volume begins to reduce by evapotranspiration and subsurface draining. The remaining standing water disappears during the summer. The wetland is annually replenished in January and December to a depth of 1 m in an effort to mimic natural hydrocycles.

• Network: AmeriFlux
  
• Principal investigators: Mike Goulden
  
• PI-affiliated institution: University of California, Irvine
  
• Primary IGBP ecosystem type: Permanent wetlands
  
• Dominant plant functional type: Marsh grass
  
• Recent and historic disturbance and management events that may affect this site:
  • Undisturbed: No disturbance or management has occurred on the site
• Flux data collection:
  • Start date: April 1998
    
  • End date: Ongoing
    
• Flux methods:
  • Eddy Covariance
    
• Optical data collection:
  • Start date: April 2003
    
  • End date: Unknown
    
• Data collection period: Continuous operation: Variable collected continuously with the reported method.
  
• Data scale: Stand
  
• Collection methods: Tram, Tower
  
• Types of data collected: Fluxes, canopy reflectance
  
• Publications:
  • Rocha, Adrian V., and Michael L. Goulden. "Large interannual CO2 and energy exchange variability in a freshwater marsh under consistent environmental conditions." Journal of Geophysical Research: Biogeosciences (2005–2012) 113, no. G4 (2008).
  • Rocha, Adrian V., and Michael L. Goulden. "Why is marsh productivity so high? New insights from eddy covariance and biomass measurements in a Typha marsh." agricultural and forest meteorology 149, no. 1 (2009): 159-168.
  • Ojanguren, Clara Tinoco, and Michael L. Goulden. "Photosynthetic acclimation within individual Typha latifolia leaf segments." Aquatic Botany 111 (2013): 54-61.

External homepage: https://ameriflux.lbl.gov/sites/siteinfo/US-SJ1

External homepage: https://www.ess.uci.edu/~marsh/