Hydrology-mediated differential response of carbon accumulation to late Holocene climate change at two peatlands in Southcentral Alaska

► Surficial geological differences influence peatland drainage and water-table depth. ► Water-table variability impacts decay of organic matter and peatland C storage. ► Surficial geological controls can influence peatland response to climate change. ► Peatland response to climate change within the same region is heterogeneous. ► Geologic controls on peatlands are important for peat-based paleoclimate studies.