MACROFOSSIL AND BIOMARKER RECORD FROM HUDSON BAY LOWLAND SOUTH RIDGE HOLLOW BOG, NORTHEAST ONTARIO

A sediment core was taken from VM Bog Tower + 375 m South Ridge Hollow in the Hudson Bay Lowlands of Northeast Ontario at 52°69’ N, 83°94’ W. Ontario’s Hudson Bay Lowlands are predominantly comprised of bogs and fens (approximately 60%) and characterized by a cool, moist subarctic climate with sporadic permafrost in the area from which the core was taken (Riley, 2011). Bogs in the region can be treed or open, and are typically dominated by Sphagnum fuscum as well as various shrubs including Chamaedaphne calyculata and Vaccinium spp., with ridges comprised primarily of conifers such as Picea mariana. The core depth extends to 258cm and has been dated using radiocarbon. By analyzing the presence of macrofossils and leaf wax biomarkers in the sampled peat, this paper seeks to reconstruct past vegetational and climatic conditions. While pollen analysis provides important information about regional distribution of plant species, macrofossils are more indicative of the presence of local species as they generally do not travel as far as pollen and spores. Further, hydrogen isotope ratios of leaf wax biomarkers can provide paleohydrological information. Completed samples, extending to a depth of 20 cm, indicate the presence of Picea spp., Larix laricina, Chamaedaphne calyculata and possibly Vaccinium spp., in addition to the dominant (~90%) Sphagnum spp. typical of bogs in the region. Cyperaceae spp. remains appear to be present at a depth of 18 to 20 cm from the surface, along with fungal remains. These findings are generally consistent with surface vegetational observations. Further analysis of greater depths, however, may reveal vegetational shifts.