Soil-Forming Factors in the Rocky Mountains of Southwestern Alberta, Canada

The main soil forming factors are climate (principally water balance), parent material (texture, porosity, and chemical composition), vegetation (especially on avalanche slopes), topography (aspect and slope angle), and time. Important local factors are fires and avalanches. Least well known is the effect of time, but a study of 10 soil profiles on each of four moraines ranging in age from the end of the 19th century to about 9000 radiocarbon yr BP at Lake Louise indicates that podzolization was proceeding much faster prior to the deposition of the Mazama ash (6600 to 7000 yr BP) than subsequently. Since we know from other studies that temperatures were higher, precipitation must have been greater at that time. Although volcanic ash weathers quickly, the effect of the volcanic ashes on profile development is dwarfed by the climatic change.