Dissolved organic carbon (DOC) dynamics vary across landscape units. The Taiga Shield ecozone, a subarctic region of the Canadian Shield, is a mosaic of different landscape units including exposed bedrock, forested hillslopes, peatlands, wetlands, and lakes. DOC exported from these units to downstream systems can influence aquatic life and carbon emissions in this lake-rich region. Lower hillslopes, including forested hillslopes and peatlands, receive DOC from external inputs (precipitation, snowmelt, bedrock inflow) and internal sources (throughfall, organic/mineral soil layers) and transformations can also be important. The role of these landscape units, however, as a contributor to downstream DOC export is not well understood in the Taiga Shield. During snowmelt and post-snowmelt periods, in 2024 and 2025, field trips were conducted to characterize DOC fluxes and quality of different water sources. Results indicate that bedrock inputs from higher topographic positions are the main external DOC load, particularly during snowmelt period. The highest DOC concentrations from forested hillslope occurred in surface water and organic layers, while peatlands showed peak concentrations in surface water during snowmelt and groundwater during post-snowmelt. Optical results revealed both forested hillslopes and peatlands transform DOC into more aromatic, recalcitrant, and higher molecular weight compounds. Also, Peatland DOC shows higher concentration and recalcitrance than forested hillslopes but is less likely to be exported due to hydrological isolation (by bedrock topography). This research highlights the critical influence of seasonality and landscape processes in shaping DOC dynamics and provides improved representation of carbon transport and transformation in the subarctic Taiga Shield ecozone.