Carbon budget for a British upland peat catchment

Area of Science:

• Environmental Science
• Ecology
• Geochemistry

Background:

• Upland peatlands are significant global carbon reservoirs.
• Accurate estimation of carbon budgets requires understanding all carbon flux pathways, including fluvial export.
• Previous carbon budget estimates for British upland peat may have overlooked fluvial carbon transport.

Purpose of the Study:

• To analyze fluvial carbon flux from an upland peat catchment in the North Pennines.
• To integrate fluvial carbon flux into a comprehensive carbon budget for British upland peat.
• To refine estimates of the carbon sink capacity of British upland peat.

Main Methods:

• Weekly monitoring of dissolved organic carbon (DOC), pH, alkalinity, and calcium.
• Measurement of particulate organic carbon (POC) in suspended sediment.
• Quasi-continuous measurements of flow and stream temperature, with intensive DOC monitoring during autumn.
• Calculation of annual dissolved CO(2), dissolved inorganic carbon, DOC, and POC fluxes.
• Integration with gaseous CO(2) and CH(4) exchanges and water table height data.
• Application of Monte Carlo methods to combine catchment data with literature values for national estimates.

Main Results:

• The study catchment was found to be a net carbon sink of 15.4+/-11.9 gC/m(2)/yr.
• Estimated net carbon sink for all British upland peat ranges from 0.15 to 0.29 MtC/yr.
• Fluvial carbon export is a critical, previously underrepresented, component of peatland carbon budgets.
• Primary productivity is a more sensitive factor in carbon budget estimations than fluvial carbon flux.

Conclusions:

• This study provides the first comprehensive assessment of fluvial carbon export within British upland peat carbon budgets.
• The estimated size of the British upland peat carbon sink is smaller than previously suggested.
• Understanding and quantifying fluvial carbon transport is essential for accurate peatland carbon budget assessments.