Heterotrophic soil respiration in forestry-drained peatlands

Heterotrophic soil respiration (CO 2 efflux from the decomposition of peat and root litter) in three forestry-drained peatlands with different site types and with a large climatic gradient from the hemi-boreal (central Estonia) to south (southern Finland) and north boreal (northern Finland) conditions was studied. Instantaneous fluxes varied between 0 and 1.3 g CO 2 -C m -2 h -1 , and annual fluxes between 248 and 515 g CO 2 -C m -2 a -1 . Variation in the annual fluxes among site types was studied only in the south-boreal site where we found a clear increase from nutrient-poor to nutrient-rich site types. More than half of the within-site variation was temporal and explained by soil surface (-5 cm)…