The effect of prescribed burning on some physical soil properties of jack pine sites in southeastern Manitoba
The effect of prescribed burning on physical soil properties of clear-cut areas originally supporting jack pine (Pinusbanksiana Lamb.) was studied in southeastern Manitoba.Average temperatures recorded during three burns ranged from <52 °C at 5-cm depth to 300 °C at the mineral soil – humus interface. The most severe burn increased the weight of organic horizons by 7% because of deposition of fuel residues, while the least severe burn produced a 31% reduction in the weight of the organic mantle.Soils at 3.8 and 7.6 cm under burned seedbeds reached permanent wilting point at days 9 and 23 respectively during a 30-day rain-free period. Moisture contents at similar depths on an adjacent scarified area were significantly higher than on the burn, were much less variable, and remained above permanent wilting point for the duration of the 30-day period. Burning did not significantly affect percolation rate.