EFFECTS OF FOREST FIRES ON SOIL PROPERTIES IN NORTHERN SASKATCHEWAN

Abstract

The effects of forest fires on some physical and chemical soil properties in the Black Lake region of northern Saskatchewan were determined on four burned-over areas, and results were compared with corresponding mature forested areas. Formerly, two of the burns supported jack pine forests and the other two supported black spruce forests.Temperatures, water infiltration rates, and erosion were the physical soil properties considered. Temperatures at the 1-inch and 3-inch depths in the burned-over soils averaged 10.5 F and 9.7 F respectively, higher than soil temperatures under mature forests. Water infiltration rates, compared at one location only, were not impaired. Erosion following fire was slight.Soil nutrients and soil pH were the chemical properties considered. Total exchange capacity decreased on three of the four burns, when compared with mature forests. Exchangeable hydrogen was reduced and available phosphorus increased on each of the burned-over soils. Exchangeable calcium increased on three of the four burned-over soils. No conclusions could be reached for alterations in total nitrogen, exchangeable magnesium, potassium, and sodium. On the burned-over areas acidity decreased at 1-inch depths and 3-inch depths.Forest fire influence both chemical and physical soil properties on the winter range of barren-ground caribou in northern Saskatchewan. These alterations may be important in changing the habitat to one less favorable for the germination and growth of preferred food plants.