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Title: Tulip-poplar leaf diffusion resistance calculated from stomatal dimensions and varying environmental parameters

Journal Article · · For. Sci.; (United States)
OSTI ID:5745702

The study describes the gradients of stomatal size and density in the crown of a mature forest-grown tulip-poplar (Liriodendron tulipifera L.) in eastern Tennessee. These data are used to predict leaf resistance to vapor diffusion in relation to stomatal width and boundary layer resistance. Stomatal density on individual leaves did not vary, but density increased with increasing crown height. Stomatal size decreased with increasing height of leaves within the crown. Stomatal size and density variations interacted to result in a constant number of stomata per leaf at all crown heights. Stomatal diffusive resistance values calculated from stomatal measurements and varying environmental parameters indicated that stomatal resistance controlled transpiration water losses only at small apertures (<0.6 ..mu..m). Boundary layer resistance was controlling at large stomatal apertures (>0.6 ..mu..m) and at low wind speeds (approx.100 cm/s). Under normal forest conditions tulip-poplar stomatal resistance exercised more control over transpiration than did boundary layer resistance.

Research Organization:
Oak Ridge National Lab., TN
DOE Contract Number:
W-7405-ENG-26
OSTI ID:
5745702
Journal Information:
For. Sci.; (United States), Vol. 29:1
Country of Publication:
United States
Language:
English