Abstract
Conversion of wetlands by drainage for agriculture or other anthropogenic activities could have a negative or positive feedback to global warming (GWF). We suggest that a major predictor of the GWF is salinity of the wetland soil (a proxy for available sulfate), a factor often ignored in other studies. We assess the radiative balance of two northern salt marshes with average soil salinities >20 ppt, but with high (macro-) and low (micro-) tidal amplitudes. The flux of greenhouse gases from soils at the end of the growing season averaged 485 ± 253 mg m-2 h-1, 13 ± 30 μg m -2 h-1, and 19 ± 58 μg m-2 h -1 in the microtidal marsh and 398 ± 201 mg m-2 h-1, 2 ± 26 μg m-2 h-1, and 35 ± 77 μg m-2 h-1 in the macrotidal marsh for CO2, N2O, and CH4, respectively. High rates of C sequestration mean that loss of these marshes would have a radiative balance of -981CO2 eq. m-2 yr-1 in the microtidal and -567CO2 eq. m-2 yr-1 in the macrotidal marsh.
Original language | English (US) |
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Article number | 044016 |
Journal | Environmental Research Letters |
Volume | 6 |
Issue number | 4 |
DOIs | |
State | Published - 2011 |
Keywords
- Carbon dioxide
- Methane
- Nitrous oxide
- Radiative forcing
- Tidal marsh