A lysimeter study on the effect of temperature on CO 2 emission from cultivated peat soils

Abstract

A lysimeter method was evaluated for its suitability in gas emission studies by studying the effect of temperature on CO 2 emissions (dark respiration) from cultivated peat soils. The study was carried out with organic soils from two locations in Sweden, a typical cultivated fen peat with low pH and high organic matter content (Örke) and a more uncommon fen peat with high pH and low organic matter content (Majnegården). A drilling method with minimal soil disturbance was used to collect 12 undisturbed soil lysimeters per site. CO 2 emission was measured weekly from the vegetated lysimeters and the results were compared with data from incubation experiments. The CO 2 emissions measured in the lysimeter experiment were in the same range as those in other studies and showed a similar increase with temperature as in the incubation experiment. With climatic and drainage conditions being similar in the lysimeter experiment, differences in daytime CO 2 emission rates between soils (483 mg ± 6.9 CO 2 m − 2 h − 1 from the Örke soil and 360 ± 7.5 mg CO 2 m − 2 h − 1 from the Majnegården soil) were presumably due to soil quality differences. Q 10 values of 2.1 and 3.0 were determined in the lysimeter experiment and of 1.9 to 4.5 in the incubation experiment for Örke and Majnegården respectively. CO 2 emission data fitted well to a semi-empirical equation relating CO 2 emissions to air temperature. The lysimeter method proved to be well suited for CO 2 emission studies.