© 1989 Heron Publishing—Victoria, Canada
Turbulent transfer in a deciduous forest
Dennis D. Baldocchi
Atmospheric Turbulence and Diffusion Division, NOAA, P.O. Box 2456, Oak Ridge, TN 37831, USA / Received January 31, 1989
Summary
Carbon dioxide, water vapor and other passive scalars are physically transferred between a plant canopy and the atmosphere
by turbulence. Intense and intermittent sweep and ejection events transfer most of the mass. Although the capacity for turbulence
to transfer material is high, mass transfer is coupled to the diffusive source or sink strength of the foliage and soil and
is ultimately limited to a minimum level set by the supply of material, or the demand for it. The diffusive source/sink strength
of material leaving or entering leaves and the soil is a function of many physical, biological and chemical attributes and
processes. These attributes and processes include the amount and distribution of foliage, the leaf boundary layer and surface
resistances, the turbulence and radiative regimes in the canopy, biochemical and photochemical reactions and the scalar concentration
field within and above the canopy and inside leaves and the soil. Here we discuss how these factors contribute to turbulent
transfer in a deciduous forest.
