Divergent hydrological responses to 20th century climate change in shallow tundra ponds, western Hudson Bay Lowlands

The hydrological fate of shallow tundra lakes and ponds under conditions of continued warming remains uncertain, but has important implications for wildlife habitat and biogeochemical cycling. Observations of unprecedented pond desiccation, in particular, signify catastrophic loss of aquatic habitat in some Arctic locations. Shallow tundra ponds are a ubiquitous feature in the western Hudson Bay Lowlands (HBL), a region that has undergone intense warming over the past similar to 50 years. But it remains unknown how hydrological processes in these ponds have responded. Here, we use cellulose-inferred pond water oxygen isotope records from sediment cores, informed by monitoring of modern pond water isotope compositions during the 2009 and 2010 ice-free seasons, to reconstruct hydrological conditions of four shallow tundra ponds in the western HBL over the past three centuries. Following an interval of relative hydrological stability during the early part of the records, results reveal widely differing hydrological responses to 20th century climate change among the study sites, which is largely dependent on hydrological connectivity of the basins within their respective surrounding peatlands. These findings suggest the 20th century has been characterized by an increasingly dynamic landscape that has variably influenced surface water balance - a factor that is likely to play a key role in determining the future water balance of ponds in this region. Citation: Wolfe, B. B., E. M. Light, M. L. Macrae, R. I. Hall, K. Eichel, S. Jasechko, J. White, L. Fishback, and T. W. D. Edwards (2011), Divergent hydrological responses to 20th century climate change in shallow tundra ponds, western Hudson Bay Lowlands, Geophys. Res. Lett., 38, L23402, doi:10.1029/2011GL049766.