Denitrification in a subarctic lake

Abstract

The rates of denitrification for an ice covered subarctic lake were measured by nitrogen-15 tracer techniques and the results compared to the measured decrease of nitrate in the lake during the same period. The effects of nitrate, glucose, acetate and phosphate concentration on the rate of denitrification were also investigated. Good agreement was found between the rate of denitrification and the loss of nitrate. The average rate of denitrification for the period measured was 5 µg N/ℓ·day which is in good agreement with rates determined for other subarctic and temperate lakes and semi-tropical marine environments. Glucose, acetate and phosphate were found to enhance the rates of denitrification.