Wetland Carbon Watch

Two reports brought to me courtesy of the Society for Ecological Restoration's RESTORE newsletter:

• The re-wetting of peat bogs in Ireland that had been used for the industrial production of peat fuel is being examined for its carbon sequestration value.  Up to 30,000 acres could be re-wetted over the next 20 years, but the characterization of carbon fluxes has yet to be done.
• Ohio State's Bill Mitch is reporting that wetland swales in Ohio sequester carbon at a mass of 140g per square meter.  

  “I can’t prove that with the 140 grams of carbon per year that my wetlands area sucking up the average temperature in the world is therefore going to be .001 degrees Celsius colder,” Mitsch told Ohio Sea Grant Communications. “But for the wetlands of the world, we have some calculations that suggest that carbon sequestration in wetlands on a global scale could be on the order of more than 10 percent of the carbon coming out of the smokestacks. 

  This news is, as always, double-edged: wetlands are a potential source of carbon when drained, as well as being a potential sink when restored.  As stable long-term sinks they leave something to be desired.  And do wetlands become sinks in the spring and sources when they dry out in the fall?  Annual fluxes are regionally-specific, poorly characterized, and almost certainly lack stationarity.