Key points are not available for this paper at this time.
Measurements of natural hydrocarbon emission fluxes are reported for a northeastern U.S. deciduous forest, for a northwestern U.S. coniferous forest, and for dominant tree species in the Atlanta, Georgia, region. The emission data were obtained by using a vegetation enclosure procedure and a micro‐meteorological gradient technique. Isoprene fluxes determined by the gradient method in the deciduous forest varied from 2500 μg/m 2 /h at 20°C to 8000 μg/m 2 /h at 30°C. Corresponding fluxes obtained with the vegetation enclosure method ranged from 890 to 7300 μg/m 2 /h. Isoprene fluxes determined by both methods increased exponentially with increasing temperature. Emission rates from isoprene‐emitting trees in the Atlanta area were similar to those observed in Pennsylvania. Alpha‐pinene fluxes measured in a Douglas fir ( Pseudotsuga menziesii ) forest ranged from 9 to 1320 μg/m 2 /h. Relative humidity appeared to directly influence the alpha‐pinene emission rate. The reasonable agreement between hydrocarbon fluxes obtained with two independent techniques is significant evidence of the general validity of current biogenic hydrocarbon emission rates.
Lamb et al. (Wed,) studied this question.