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DKIP

Carbon Flux Quantification in a Flooded Wetland


photo of river
A solar powered data logger collects real time plant production
and carbon accumulation data in the eastern pond of the 12-acre
Twitchell Island USGS/DWR Carbon Pilot-Scale Wetland.

Background

The USGS Carbon Group in the California Water Science Center has conducted a project for over a decade that demonstrates the extent to which peat-forming wetlands can reverse peat soil organic matter loss. This decade long project has demonstrated that the oxidative loss of soil organic matter during cultivation, representing a current flux from soils to the atmosphere of 7 Metric Tons (MT) of carbon dioxide (CO2) per acre per year, can be reversed under specific wetland conditions, resulting in fluxes of about 25 MT CO2 per acre per year into the soil substrate from the atmosphere, for a net benefit of over 30 MT CO2 per acre per year. However, despite promising initial results, there are many uncertainties that require further research before large scale implementation. The uncertainties which must be better understood are: the quantity of methane gas (CH4) and nitrous oxide (N2O) produced which can in some circumstances occur in quantities large enough to offset any CO2 sequestration in flooded wetlands on peat soils.

Project Description

This DKIP funded project which is in progress attempts to provide further research to understand the available data, measure and model the green house gas fluxes in the pilot wetland and will quantify photosynthetic fixation and carbon accretion in wetlands on peat soils.