CGRG Bibliography of Canadian Geomorphology
Search Results
Author : Bauer, I.E.; and Vitt, D.H.
Date : 2000.
Title : Lateral expansion and paleoecology of a peatland complex in central Alberta, Canada.
Publication : Annual Scientific Meeting, Canadian Geophysical Union, Banff, Alberta, May 23-27, 2000.
Issue : Abstract.
Page(s) :
Abstract
Many of the extensive peatlands in boreal western Canada are formed by paludification, i.e. the expansion of peatland vegetation into areas formerly occupied by upland communities. The temporal dynamics of this process as well as the autogenic and allogenic factors controlling it are presently only poorly understood. The developmental history of a large peatland complex in the Mid-Boreal Wetland region of central Alberta (113° 15’W 55° 03’N) was examined using a combination of mapping and paleoecological techniques. The site includes a number of different peatland types, ranging from wet, open fen to ombrotrophic bog. Basin morphometry was interpolated from over 300 depth measurements distributed along transects throughout the site. Basal radiocarbon dates from 16 cores show an overall linear relationship (R 2 =0.61) between peat depth and basal peat age. Long-term average rates of apparent carbon accumulation measured in different peatland types range from 27 g C m -2 yr -1 to 33 g C m -2 yr -1 . Peat accumulation at the site began about 7500 cal years BP, towards the end of the early Holocene warm period. Lateral site expansion was slow initially because the peatland was confined by steep local substrate slopes and peat accumulation was dependent on relatively localized supplies of moisture. Rates of peat initiation increased between 5000 cal years BP and today, probably in response to further climatic cooling and associated changes in the regional moisture balance. Macrofossil analysis of basal core samples shows differences between initial peat-forming communities from different regions of the site, indicating that the mechanism of paludification was not uniform throughout the peatland. Macrofossil analysis of selected core profiles further shows different patterns of community succession associated with different regions of the site.
Bibliography of Canadian Geomorphology