Soil Sensitivity to Acid Deposition and the Potential of Soils and Geology in Alberta to Reduce the Acidity of Acidic Inputs

The objective of this project was to prepare maps of Alberta, at a scale of 1:2 000 000, showing the distribution of soils relative to their sensitivity to acid deposition and the distribution of soils and geology relative to their potential to reduce the acidity of atmospheric deposition. This project was Alberta's contribution to a Western Canada Long Range Transport of Air Pollution (LRTAP) Committee effort to prepare such maps for the four western provinces, Yukon, and Northwest Territories in a coordinated and collaborative fashion.

When this project started, no soils base map was available for Alberta that was suitable for interpreting iron sensitivity of soils to acid deposition or their potential to reduce the acidity of atmospheric deposition. Descriptive information was assembled and synthesized for mineral soils and peatland systems throughout the province. About 350 discrete map units were delineated. These were consolidated into 215 distinct map unit types. The quality and detail of the soils information that was available for the southern half of the province and the Peace River area, and the national parks in the Rocky Mountains, was quite good. However, the information that was available for the far north and the northeastern areas of the province, and the eastern slopes, was more general. In particular, there lacked information for organic and organic Cryosolic soils, except in a few localized areas.

Expressed as a percentage of the total area of Alberta, soils (and associated geology) with high potential to reduce acidity occupy 64.4 per cent, soils with medium potential, 21.8 per cent, and soils with low potential, 11.3 per cent. Most of the southern half of Alberta and the Peace River region has soil with a high potential to reduce acidity. Soil with medium potential is in the north central, northeastern and eastern slopes regions, and to some extent in the Rocky Mountains. Soil with low potential is in the far north, the northeastern regions and the northern Rocky Mountains.