Volatile organic compound emissions from young black spruce trees

Black spruce trees are an important component of the vast northern boreal forest and therefore may influence global atmospheric chemistry. Variations in the Volatile Organic Compound (VOC) emission rate of young (3 year old) black spruce trees as a function of light and temperature were found to be consistent with the functions suggested by Guenther et al. [Guenther, A., Monson, R., Fall, R. (1991). Observations with eucalyptus and emission rate algorithm development. J. Geophys. Res., 96(D6):10799-10808]. VOC emission rates were determined using a fast response hydrocarbon detector in conjunction with a glass cuvette. This allowed the VOC emission rate to be determined on a real-time basis. Summation of separate equations for isoprene and monoterpenes yielded a predictive total VOC emission rate model as a function of light and temperature which was based on total hydrocarbon data provided from the fast response hydrocarbon detector. Speciations of the spruce emissions provided further evidence that temperature relationships of the isoprene and monoterpene emission rate could be fitted to the general functions proposed in the literature. The base VOC emission rate at standard conditions was found to be 9 ± 4 μg C h^-1 (g dry needle weight)^-1.