Plant-derived CO2 flux from cultivated peat soils

Methods used to estimate the CO2 emission from soil commonly measure the total CO2 flux. To be able to quantify the net CO2 emission from cultivated peat soils there is a need to distinguish between soil organic matter-derived CO2 respiration and plant-derived respiration. In this investigation we used the root exclusion method to separate the plant-derived respiration from total CO2 emission. The plant-derived contribution was estimated to be between 27 and 63% of total CO2 emission depending on soil type and season. We also found a relationship between soil temperature, biomass growth and CO2 efflux, which can be used to estimate plant-derived respiration. Due to the priming effect the root exclusion method is less reliable late in the season.