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In an upland forest in the Experimental Lakes Area (ELA), Ontario, dissolved organic carbon (DOC) concentrations in precipitation increased with passage through a forest canopy, as throughfall and stemflow. A maximum mean concentration of 67 mg/l occurred in the forest floor, which decreased to 11 mg/l in the B horizon, as DOC was sequestered in the soil. High DOC concentrations were measured in an ephemeral stream draining the upland, as a result of saturated overland flow, and the leaching of litter and woody material. / Porewater DOC concentrations decreased with depth in two bogs. The porewater DOC was comprised primarily of acidic fractions (70 to 87%), with a predominance of hydrophobic acids. The bogs were significant sources of DOC, exporting between 17.2 and 29.4 g DOC/m$ sp2$ over the study period. In 1993, a bog was flooded simulating the creation of a hydroelectric reservoir, and resulting in significant increases in porewater DOC concentrations at the surface. A maximum surface concentration of 223 mg/l was measured in late September. The flooding of the bog also resulted in significant increases in DOC concentrations in the draining waters, with the outflow of the watershed increasing from a mean of 20.5 mg/l in 1992, to 14.7 mg/l in 1993.