ACID-PHOSPHATASE, ALKALINE-PHOSPHATASE AND ARYLSULFATASE ACTIVITIES IN SOILS FROM A JACK PINE (PINUS-BANKSIANA LAMB.) ECOSYSTEM AFTER CLEAR-CUTTING, PRESCRIBED BURNING, AND SCARIFICATION

Acid phosphatase, alkaline phosphatase and arylsulfatase activities we re determined from organic and mineral soils of a jack pine (Pinus ban ksiana L.) community 4 years after clear-cutting alone, clear-cutting followed by prescribed burning and clear-cutting followed by scarifica tion. Controls consisted of uncut plots. Prescribed burning lowered so il enzyme activities in the organic layers as compared to the other tr eatments. Acid phosphatase activity correlated with pH, log of fire in tensity, consumption of total surface fuels and consumption of total f uels. Acid phosphatase was also inversely related to soil pH. The resu lts suggest that acid phosphatase activity may be useful for assessing the impact of fire on soils. The use of soil enzymes to predict post- fire changes in soil quality and subsequent ecological phenomena is al so discussed.