Spatial patterns of duff consumption in black spruce and jack pine stands in the boreal mixed wood forest



Bajtala, Mark J.

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University of Guelph


The major force driving most boreal vegetation dynamics is fire. The goal of this study was to determine and explain the spatial patterns of duff consumption in wildfires in the Canadian boreal forest, which influence the patterns of tree regeneration after fire. Duff consumption occurs primarily by smouldering combustion which is influenced largely by duff moisture. Black spruce stands have significantly larger (up to 10x) and fewer (up to 3x) burned patches of duff than jack pine stands. Patterns of duff consumption in 17 burned stands (8 jack pine, 9 black spruce) were compared to patterns of duff moisture, bulk density, depth and composition in 17 comparable unburned stands. The data were collected in central Saskatchewan near Prince Albert National Park in 1996 and 1997. Differences in general stand characteristics (standing stem density and species composition) between black spruce and jack pine stands do not account for the differences in duff consumption patterns. Further investigation into duff consumption patterns should look more closely at the effects of canopy cover, and standing stem distributions and the influence of moisture within the litter, fermentation and humus layers separately. (Abstract shortened by UMI.)



Duff consumption, Wildfires, Canadian boreal forest, Tree regeneration, Saskatchewan