Carbon storage change in a partially forestry-drained boreal mire determined through peat column inventories

To study the impact of forestry drainage on peat carbon storage, we cored paired quantitative peat samples from undrained and drained sides of an eccentric bog. Five pairs of 0 to ≤ 100-cm-deep surface-peat cores, and a pair of profiles representing the full peat deposit provided stratigrapic evidence of marked loss of surface peat due to drainage. For the drained side cores, we found a relative subsidence of 25-37 cm of the surface, and a loss of about 10 [kg.sub.DW] [m.sup.-2], corresponding to 131 ± 28 g C [m.sup.-2] [a.sup.-1] (mean ± SE) for the post-drainage period. Similar peat loss was also found in the full deposit profiles, thus lending credibility to the whole-column inventory approach, even though the decrease (9 [kg.sub.DW] [m.sup.-2]) was relatively small in comparison with the total carbon storage (233 and 224 [kg.sub.DW] [m.sup.-2] for the undrained and drained sides, respectively).