Biogenic volatile organic compound emissions from a boreal forest floor

A dynamic soil chamber was used to quantify biogenic volatile organic compound (BVOC) emissions from the forest floor of a Norway spruce and Scots pine dominated boreal forest. To carry out measurements (five campaigns from June to October 2015), six plots were randomly selected. The BVOC emissions from the forest floor ranged from 0.4 to 66.6 µg m–2 h–1, and the emission rates peaked in October with an average of 10.26 µg m–2 h–1 when the litterfall biomass was the highest and the air temperature was the lowest (< 10 °C). Monoterpene (MT) was the main group of detected BVOCs, their contribution to total BVOC emissions from the forest floor being > 80%, while the contribution of isoprene was close to zero during all campaigns and the sesquiterpene (SQT) emissions in September and October were negligible. α-pinene, ∆3-carene and camphene were the dominant MT compounds throughout summer and autumn. The MT emission rate increased exponentially with air temperature inside the soil chamber from June to September. Variations among the frames and in time indicate that needle litter may be an important source of BVOC emissions.