Greenhouse Gas Fluxes from Dutch Peatland Water Bodies: Importance of the Surrounding Landscape

Abstract

Methane and carbon dioxide fluxes were quantified for 14 ditches and larger water bodies in Dutch peatlands, surrounded by different habitat types, using concentration changes in floating flux chambers. Average fluxes from these waters were 11 ± 2 (mean ± SE) mg CH4 m−2 h−1 (n = 66) and 86 ± 21 mg CO2 m−2 h−1 (n = 55). Variability among water bodies was substantial in both gases and could be explained by water depth and surrounding habitat. Ditches in intensively used dairy land or rough pastures had significantly higher CH4 emission rates (17 ± 6 and 18 ± 8 mg CH4 m−2 h−1) than those in reed and sedge beds or open water (7 ± 1 and 5 ± 2 mg CH4 m−2 h−1). Bubbles contributed between 34 and 69% to the total CH4 flux, with higher proportions observed in ditches sheltered by tall vegetation. Observed day-time CO2 fluxes were either positive (shaded ditches in reed and sedge stands or rough pasture; 120–150 mg CO2 m−2 h−1) or did not differ from zero (open water, ditches in intensively managed pasture). Since these peatlands have substantial areas of permanent surface water (6–43%), landscape-scale carbon flux estimates are improved by incorporating specific flux estimates for these waters.