Effect of drainage on CO2 exchange patterns in an intensively managed peat pasture

[摘要] ABSTRACT: Eddy correlation measurements of CO₂ exchange were made in intensively managed peat pastures at 2 different groundwater tables during most of a growing season. F was separated into a respiratory and an assimilatoryCO₂ flux. The fit of the Arrhenius temperature response to F_r showed that F_r was generally higher at low groundwater tables. The fit of a hyperbolic irradiance response to F_a showed thatF_a was also generally higher at low groundwater tables, more than compensating for higher F_r. The daily CO₂ balance suggested that the low groundwater pasture was a larger CO₂ sink or a smallerCO₂ source than the high groundwater pasture during the measurement period. The difference in F_r between the groundwater tables was substantially less than the factor 2 difference in level of soil subsidence. This suggeststhat oxidization of soil organic matter was a relatively minor factor in soil subsidence.

[关键词] Eddy correlation;CO2 exchange;Assimilatory flux;Respiratory flux;Pasture;Grassland;Peat;Drainage