The role of climate on the developmental history of Frontenac Peatland, southern Quebec

The developmental stages, hydrological conditions, and net peat accumulatio n rates at three coring sites of Pare de Frontenac Peatland (Quebec) were r econstructed to examine the role of climate on pent accumulation. During th e early to mid-Holocene, elevated temperatures proved to be a more critical factor for sustained peat production than precipitation, because peatland development occurred mostly under a dry climate according to a low lake-lev el stage lasting from 11000 to 7000 calibrated (cal.) BP in a nearby lake. Between 7000 and 6000 cal, BP, elevated net pent accumulation rates roughly correspond with a rise in lake water level, suggesting that higher precipi tation and (or) less evapotranspiration then favored peat growth. A decreas e in peat accumulation occurred from 5000 to 2500-1500 cal. BP, while the l ake level was high from 4400 cal. BP. An important increase in net pent acc umulation rate is recorded for this entire peatland from 1500 cal. BP. Lack of close timing between fake level changes and changes in pent accumulatio n rates or surface hydrology suggest that temperature and autogenic process es were often more important than regional water balance in the development al history of the peatland.