PARENT SESSION
Organized Oral Session 6: Development of landscape heterogeneity at multiple scales in wetlands
Organizer(s): B Warner and A van der Valk
Monday, August 8, 8:00 AM - 11:30 AM, Meeting Room 516 A, Level 5, Palais des congrès de Montréal
Environmental controls on vegetation patterning in large boreal peat basins.
Glaser, Paul1, Siegel, Donald2, Reeve, Andrew 3, 1 Department of Geology and Geophysics, Minneapolis, MN, USA2 Department of Earth Sciences, Syracuse, NY, 132443 Department of Earth Sciences, Orono, Maine, USA
ABSTRACT- A few large peat basins in boreal North America and Eurasia contain a significant fraction of the world's peat deposts. These large peat basins are characterized by their low relief, extensive peat cover, and striking vegetation patterns. Investigations in the Hudson Bay Lowlands (HBL) of Ontario and Glacial Lake Agassiz peatlands (GLAP) of Minnesota indicate that the development of the vegetation/landform patterns is intimately related to the dynamics of groundwater flow systems driven by a changing climate or isostatically rising landscape. In both regions the distribution of raised bogs, fen water tracks, and spring fens is closely coupled to groundwater flow systems that either transport dissolved salts vertically upward from the underlying glacial deposits to the peat surface or drive the movement of precipitation downward through the peat column. Raised bogs, for example are restricted to locations that will support the growth of water table mounds, whereas fen water tracks function as conduits for runoff on more steeply sloping aspects of the landscape. Pool patterns are related to changes in peat slopes, flow constrictions, and developmental stage. The developmental pathways in these large peat basins, however, must continually adjust to climatic or tectonic drivers that perturb the interaction between local and regional flow systems.
Key words: peatland, vegetation patterning, groundwater, environmental change